Academic Program At CEPT

A World Summit for Sustainable Development (WSSD) in Johannesburg in 2002 recognized the access of energy services as a prerequisite to the achievement of all MDGs. Only 2/3 population of the world has access to electricity and around 2.4 billion worldwide rely on traditional biomass for cooking. These clean energy resources must be maximally used to meet the cooking and lighting needs of the households. While electrification and clean energy for cooking are not essentials to sustain life, they are socially and environmentally desirable.

This study was mainly done using stakeholder and occupant survey analyses of the everyday practices of urban poor inhabitants with regards to energy access and consumption and concomitant economic, social, environmental and political implications at the household and neighborhood levels. A proper base data documentation was conducted of the selected sites in Ahmedabad for understanding the energy use, patterns and needs of urban poor both in quantitative and qualitative nature. The sites included Gulbai Tekra: un-intervened slum, Garodiya Tekra & Jadiba Nagar: Upgraded slum, Ekta Nagar: Slum rehabilitation project, Swarnim Nagar: Resettlement housing & Gota Public Housing: EWS public housing. The paper brings out the ground situation of the existing schemes and subsidies related to clean energy and electrification. The ground study revealed that more than 90% of beneficiaries do not get the scheme benefits especially in the schemes relating to Electricity while only around 40% of the surveyed people have received some sort of scheme benefits for LPG cylinder. The hazards of unclean energy are more seen in closed spaces which were evident from the surveys in Swarnim Nagar- a 4 storeyed slum resettlement project show that around 45% of people suffered from sort of health issue due to the usage of wood/ gobar in corridors. The budget for LPG cylinders is also kept under budget by the poor by using secondary fuels predominantly wood. This can be seen both in vertical and horizontal housing development. Even when 90% have access to formal electricity and LPG connections, they suffer tremendously due to high recurring consumption bills. Due to this, in LPG cylinders, people have restarted using woods as their secondary cooking fuel. Studies and surveys from new public housing projects namely the Ekta Nagar rehabilitation project, Gota Public Housing Project have shown a very significant shift to cleaner fuels mainly because of strict RWA policies disregarding the use of unclean fuels and also because of the ready availability of cleaner fuels i.e. Gota already has CNG connection by Athani which has significantly brought down the cooking fuel cost and is also based on the usage, Ekta Nagar is also slowly shifting to CNG. Residents find it very difficult to afford the cost of LPG (Rs.830/Cylinder) on a one-time basis in Gulabi Tekra, Jadiba Nagar and Garodiya Tekra and also in Swarnim Nagar where they shift to unclean sources as they can buy them in smaller amounts of Rs.10-Rs.20 / kg for wood and Rs1 / Piece for gobar cake. In the case of electricity as people do not have money to pay the electricity bill, they pay in parts and previous dues begin to accumulate which finally ends in huge resulting in disconnecting the connection when that situation arises, the residents borrow money from moneylenders for high interest and pay which ends up being a huge financial burden to the users, this is mainly seen in slums and upgrade slums.

The main recommendations made in the study are to focus on schemes and subsidies on recurring consumption costs because presently that is the main barrier in maintaining the clean energy sources in the ground now. Subsidies, payment systems to pay installation cost in smaller payments, the energy efficiency of appliances, prepaid electricity can be some methods to tackle this problem.

Abstract: With unprecedented urbanization, India is expected to see a steep rise in the residential cooling demand. Despite the alarming projection, the ‘what, why, and how’ of cooling behavior remains fairly less explored in the Indian context. As stressed upon by IEA Anne 53, variation in behavior often leads to a mismatch in the actual and predicted energy performance of the buildings leading to greater issues such as higher return on investment and unachieved energy targets. Behavioral uncertainty leading to unreasonable peak demand has become one of the major challenges for the government and distribution companies in the tropical regions.Detailed observations and understanding of the behavioral variables can lead to a tailored policy approach responding to different household groups. While there have been several instruments identified to understand occupant behavior, often they have been reported to be too impractical and cost-ineffective by the past researchers. Amidst the unfortunate scenario and restrictions, the introduction of smart metering systems worldwide is proving to be a boon. The availability of real-time electrical data communication has led to a lot of interesting insights useful to energy policymakers in the developed countries. The launch of the Smart Meter National Programme and its aim of replacing 25 crore conventional meters with smart meters will lead to a huge amount of data generation in India as well. With such upcoming technology, it becomes vital for the community to explore the possibilities and insights that can be generated through the data leading to better energy security in India. The study evaluated the cooling behavior by using machine learning and statistical analysis on the data collected through the smart meters installed in 34 households of Mathura and Bareily. It raises a set of fundamental questions around the parameters that determine the AC usage behavior in Indian households. Based on the commonalities 3 prominent groups of households were found i.e (1) Active users (2) Average users (3) Conscious users. Their usage characteristics and the possible strategies (Behaviour, building, or equipment level) has also been discussed as a part of this study.

Abstract: Natural ventilation (NV) has the potential to influence indoor air quality (IAQ) in built microenvironments. Not only NV is an important energy-saving factor, but from a health, wellness, and comfort perspective, it is crucial. The Residential Energy Conservation Building Code (BEE, 2018) identifies it as one of the potential passive strategies to reduce energy use, by allowing NV in favourable outdoor conditions. However, its full potential couldn’t be utilized due to unavoidable constraints of severe outdoor air pollution in many urban environments. Several studies have shown that a higher air exchange rate (ACH) can be an energy-efficient measure to improve IAQ. This study attempts to monitor IAQ for similar events in a heavily polluted environment and correlate the result with the measured ACH higher to understand the indoor/outdoor (I/O) air pollution ratio. Dilution of the indoor pollutant is the only method to enhance the IAQ in the naturally ventilated spaces, by providing the required outdoor fresh air. However, the impact of such dilution when the outside is polluted is an understudied area of research. This study to curb the identified gap was carried out in the polluted urban environment of Gwalior, Central India, during the winter months of December 2020 to March 2021.A two-part methodology was developed for conducting the study, in the first part, the ACH was measured on selected 30 naturally ventilated bedrooms to find out if they meet the ventilation standards. In the second part of the study, the primary sources of air contaminants in the bedroom micro-environment were monitored indoors and outdoors. The result of the effect of the independent variables such as window type, number of windows, location of the opening, floor height, mesh, surrounding built-up density, etc. was compared with the ACH and IAQ to analyze the indoor/outdoor ratio.The ACH results presented a weak correlation between the measured data and the code recommendation of 12.5% of the openable window to floor area ratio. Only one bedroom was found to meet WFRop's recommendation, but 16 bedrooms were found to meet the standard for ventilation requirements. This realized that other parameters also have an impact on ventilation requirements. Further results indicated that infiltration and cooking are the major cause of indoor air pollution with 57% and 27% respectively. This indicated that even with a closed window, levels of pollution inside may be identical to those outside. Other results showed that the bedroom with a higher ACH was found to have a lower indoor to outdoor pollution ratio, However, these bedrooms also had more polluted hours because of infiltration (Outdoor pollution). The study focused on to what extent natural ventilation might be an energy-saving measure to improve indoor air quality during the episode of outdoor pollution and the conclusion and recommendations were made concerning design characteristics to improve NV and IAQ

Abstract: The air-conditioning system is one of the major consumers of electricity in an urban context with the window/glazing in the building being the weakest elements in the envelope susceptible to heat ingress. In India, the HVAC system comprises 40% of the building's energy consumption. Thus, it is crucial to have a detailed building characteristic dataset to develop a robust Urban Building Energy Model (UBEM) to estimate the annual energy demand and consumption profile. UBEM can be used to evaluate retrofit or design options and study the impact of climate change or other extreme environmental events. Generally, the process of data collection for the same is through construction documents or a large-scale field survey. This process will require an unreasonably high human effort and time which will impact its scalability and replicability.

In this study, a method is proposed to estimate the window to wall ratio (WWR) and air-conditioning status of a building from its ground-view façade imagery. The input image dataset includes visible and thermal IR images of the same perspective, captured using a thermal camera. The method consists of an algorithm that is divided into 3 segments. The first, consisting of an object detection classifier using Faster R-CNN, a deep neural network, is used for building and window detection from the visible input images. The second segment calculates the area of the bounding boxes of the objects which are used to estimate the window-to-wall ratio. The third segment super-imposes the bounding coordinates onto the thermal image to extract the pixel values which represent the surface temperature of the window and external wall region. When the difference between the window and the wall regions is greater than 7oC, it is regarded as air-conditioned. For object detection classifier with a precision of 57% (based on the training dataset used) estimates the WWR with a variation of 40%.

The algorithm developed through this thesis can help develop a rich dataset to generate an urban building energy model with LoD3 (Level of Detail). This mode of data collection has better scalability and replicability to make it both a time and cost-effective method to be adopted in developing the building stock model for energy modeling. This resultant Urban Building Energy Model can simulate the energy performance of the buildings in the urban environment to provide quantitative and qualitative insights for the stakeholder to provide informed decisions.

Abstract: The building envelope is a barrier to ambient conditions and its composition influence heat transfer. Walls and roof form a major portion of the building envelope hence, an envelope with high thermal performance acts as an energy conservation measure, providing indoor thermal comfort. A Laterite and rammed earth residence were considered as the study subjects and the thermal performance of the walls with its influence on the indoor conditions were analysed. The study was spanned over a period of 3.5 months where surface temperatures of the walls oriented to different directions and indoor conditions of its adjoining spaces were monitored. The laterite stone walls showed a mean inner surface temperature of 29.3°C to 30°C on all the walls oriented along different directions. The indoor air temperature was observed to have a mean of 30.8°C whereas the indoor mean radiant temperature, a measure of the radiant impact of the surfaces had a mean of 31.3°C. In the rammed earth residence, the mean inner surface temperature was least for north wall at 27.3°C and highest for south wall at 28.4°C. The mean outer surface temperature ranged from 29.4°C on the north wall to 34.1°C on the south wall. The large difference between outer surface temperature and inner surface temperature of the rammed earth wall can be attributed to the high thermal conductivity of the walling material. The indoor air temperature was observed to have a mean of 30.7°C whereas the indoor mean radiant temperature, a measure of the radiant impact of the surfaces had a mean of 30.2°C. The lower mean radiant temperature compared to the air temperature showed that the walls provide a cooling effect for the indoor spaces. As the building designs are not identical, an attempt to analyse spaces with similar exposure and adjacency was done have a preliminary understanding of the difference in the two materials. Comparing the distribution pattern of the surface temperatures of the east wall showed that 45% of inner surface temperature for rammed earth and 97% of inner surface temperature for laterite stone were more than 28°C. Hence rammed earth wall due to its thermal properties has an overall 2°C lower surface temperature compared to laterite stone wall. Comparing the indoor air temperature and relative humidity levels, it was observed that 76% of the data for rammed earth observed a temperature less than 31°C while the relative humidity was less than 68%. The thermal simulation study found that with the use of rammed earth, cooling load for a space can reduce by 10%. Additionally, the rammed earth wall had a lower time lag of 5 hours compared to laterite stone of 7 hours which showed that the walls cool faster due to its higher thermal conductivity, which helps naturally ventilated buildings to lose heat faster and cool leading to higher comfort levels.

Abstract: A field study of windows was carried out for six institutional and hospitality buildings located in Delhi and Ahmedabad to assess the impact of dust on daylight transmittance of glazing. Vertical illuminance measurements were taken using a lux meter to calculate the relative percentage loss in visible light transmittance (VLT) due to dust on glazing. The measurements were carried out under overcast conditions for stabilized illuminance readings. The VLT loss was observed to be between 2% - 11% for over 75% of the 108 windows that were studied. Factors affecting the dust deposition included (but were not limited to) shading type and length, exposure to indoor or outdoor dust, indoor room conditioning and frequency of cleaning. The range of light transmittance loss was found to be 0.8% to 29.69% while the mean was recorded as 8.72%.

To analyze the worst-case scenario and the extent of soiling that a glass surface can undergo, a glass sample was soiled in laboratory by repeatedly spraying (aqueous dust solution) and drying the sample till dust saturation was reached. A relative loss of 55% in glass VLT was observed after 30 consecutive soiling cycles, beyond which soiling the glass further did not yield considerable difference in its light transmittance. A soiling saturation curve was derived out of this experiment to inform the inputs in daylight simulations carried out in LightStanza.

Annual daylight simulations for the Academic block in Indian Institute of Management, Ahmedabad were performed which showed a maximum relative decrease of 62.8% in Useful Daylight Illuminance (UDI) due to VLT deterioration because of dust deposition on windows. A 139% increase in average percentage of hours falling under insufficient illumination (<100 lux) was observed when the windows were dirty. The magnitude of change in horizontal illuminance levels was found to be perceptible to human eyes.

Simulations were carried out to assess the impact of dusty windows on lighting energy of two typical rooms in the building. The rooms were provided with manual switching controls and automatic daylight dimming controls to observe the impact of daylight dimming and regular cleaning on lighting energy consumption. The absolute effect on annual energy consumption was observed to be insignificantly low (lowered by ≈120 kWh/ room) when considered for its impact at the building level.

Abstract: In the last 10 years, 43% increase has been observed in heat wave incidents in the city of Ahmedabad located in the hot and dry climatic region in India. With average summer maximum daytime temperature of 41⁰C and increased frequency of extreme weather conditions, occupant controlled passive design measures such as external movable shading devices are an important strategy for integrating resilience into buildings to provide indoor comfort.

This study is focused on understanding the occupant behavior in operating external movable shades control installed in balconies of residential buildings in Ahmedabad, India. External balcony shades influence direct solar gains incident on the balconies, access to daylight and views in the indoor spaces, air movement in the balconies and adjacent spaces. Occupant behaviour was observed in terms of frequency of shade deployment and frequency in change of shade position in response to outdoor environmental conditions. From the frequency of shade movement, the proportion of occupant behaviour has been further categorized as: passive, active and non-users.

Passive users are defined as occupants moving their shades occasionally i.e. less than four times for a defined study period whereas Active users move their shade frequently at a rate more than four times throughout the study period. Non-users do not move their shades even once during the entire study period. In this study, the factors influencing the active and passive users are considered to understand the strongest correlation variable with the average shade occlusion.

Abstract: Air is the primary carrier of contaminants/pollutants in an indoor space and a governing parameter in achieving an acceptable indoor air quality. People spend more than 90% of their daily life indoors. Hence, it becomes inevitable to maintain the indoor spaces clean and healthy, which profoundly affects the productivity and safety of the people in the space. The testament from various researchers, research organizations, and civic health bodies of various nations regarding air being the primary carrier of the contaminants demands a need to investigate the transmission impact and measures that can reduce these effects. The ASHRAE building readiness guide advises an increase in outdoor air ventilation and enhanced filtration as solutions at the system level. The measures suggested address the contaminant transmission impact by varying the outdoor air fractions and providing effective filtration systems. These can lead to a rise in energy consumption or changes to the system size, having monetary and environmental impacts.

Centers for Disease Control and Prevention describes controlling exposures as a fundamental method to protect people indoors. Previous research studies have shown that improving ventilation effectiveness enhances indoor air quality without necessarily increasing air change rates. However, these studies are limited to clean rooms and laboratories, which function at higher air change rates. This research study investigates air distribution systems’ ability for effective air distribution in the occupied zone considering a contaminant source (occupant-generated) in the room.

Ceiling diffusers have a significant impact on indoor air temperature and air velocity. This study focuses on the predominant air distribution systems of mixing ventilation used in office spaces in India, with mainly three types of ceiling diffusers, i.e., square, round, and vortex. This study aims to understand the impact of the ceiling diffuser types, their relative location to occupants on the airflow patterns, and the quick removal of airborne contaminants. The fluid flows are analyzed by computational fluid dynamics (CFD), which uses numerical analyses and structured data using the finite volume method to solve the room's air distribution. The present study considers tracer gas as internally occupant-generated pollutants. Multi-objective optimization is performed for all the parametric combinations using modeFRONTIER, which uses a machine-learning methodology to mimic the CFD solver and reduce the computational time. The workflow tests with various optimization algorithms and produces local and global optimum results.

The assessment of air distribution due to the diffuser type and its location is carried out by evaluating air distribution performance index (ADPI), air change effectiveness (ACE), and ventilation effectiveness (VE), gaining insights into desired airflow patterns and control method for occupant generated contaminants. The outcome of this study will suggest an optimum diffuser design and its location for the office space. This research study will further help identify retrofitting measures that can be energy-efficient, propagate a measure for maintaining healthy office spaces, and be involved as a design intervention at HVAC system design stages.

Abstract: The study is conducted at Centre for Environmental Planning and Technology (CEPT) University, and focuses on split air-conditioning systems throughout the entire university campus, as it is the most predominant system amongst all HVAC systems installed. The global split air conditioning systems market is expected to grow at a noteworthy Compound Annual Growth Rate (CAGR) of around 4.3% and reach around US$ 178 billion by 2026. Rising global temperatures coupled with population growth and an increase in disposable income, make India and other southeast Asian countries vulnerable to higher demand for air-conditioning systems. Bureau of Energy Efficiency (BEE) launched a standard and labeling program for RACs in 2007 and revised the energy efficiency norms periodically, resulting in overall efficiency improvement to the extent of 36%. However, there is further potential to improve the efficiency of RACs to meet the rising energy demand, and installing these systems while replacing existing systems is the challenge. Along with strong policies supporting this action, it requires more case studies proving the same to be beneficial. For that purpose, the following study is being conducted, taking into account various parameters which can affect the performance of a split–air conditioner, and along with it the cost-benefit that is derived not just by upgrading to more efficient systems but how better maintenance can prove to be beneficial. It also considers their reduced impact on the environment considering the use of less harmful or 'green' refrigerants, and reduced power consumption. The study focuses on operational performance, climate impact, and economic assessment of 135 split-air conditioning units at the CEPT University Campus, ranging from 1.4 TR to 2.1 TR. It also considers the climate impact due to the different measured power consumption, air-flow, filter condition, type of refrigerant used, etc. The key findings show that a majority (71 units) are of 1.5 TR capacity. And 94 units use R22 as a refrigerant, which will eventually be phased out. This forms a strong base to consider a replacement scenario, with strong climate and environmental benefits. The study finds that the measured performance reduces by an average of 16% for all units. The payback period when considering super-efficient air-conditioners with an ISEER rating of 5.6, using R32 refrigerant, was less than 3 years, while the climate impact is reduced by 70% and 80% when compared to R22 and R410A respectively. Replacing all the existing units with super-efficient air-conditioners is a step in the direction of reducing the climate impact due to the inefficient performing air-conditioners.

Abstract: Human activities are causing climate change. Greenhouse gas emissions are specifically the leading cause of the rapidly changing climate. Net Zero Energy buildings are one of the solutions to cater climate change problem in the construction sector. These net-zero energy buildings are meant to perform net-zero throughout their life span. Major building simulations are however for the net-zero energy buildings done using typical weather files. Typical weather files are being generated using historic weather data, which represent past years. As, the Indian context, life span of the building is expected to be 75 to 100 years, it is expected to perform net-zero throughout the lifespan from the building. Hence future weather files are important to be looked at. IPCC has developed the weather scenarios for future climate. Based on these weather scenarios future weather files can be generated. While designing such futuristic buildings, in the building simulation future weather data could be one of the focus points. CARBSE is a net-zero energy building at CEPT University, Ahmedabad. That same is considered as the case study as a part of this thesis work. The building has recorded all the energy usage data from the year 2016 to 2019 for evaluation, as it is a living lab for building energy performance. This study starts with understanding and generation of future weather files. Secondly, comparing future weather files and typical files with the actual years for better understanding. Climate analysis and scope of passive strategies in future years are a major concern as the building uses such energy conservation measures to reduce cooling load. Building performance assessment and net-zero status check are done for the same weather years. If the building is not managing to maintain its status of net-zero, what are the reasons behind the same are looked at in detail? Refurbishment solutions for Envelope, HVAC systems and Renewables are proposed and evaluated by the cost as well. From all the above refurbishment solutions, a method can be developed to evaluate net-zero energy building according to owners’ perspective for energy and cost.

Abstract: Human activities are causing climate change. Greenhouse gas emissions are specifically the leading cause of the rapidly changing climate. Net Zero Energy buildings are one of the solutions to cater climate change problem in the construction sector. These net-zero energy buildings are meant to perform net-zero throughout their life span. Major building simulations are however for the net-zero energy buildings done using typical weather files. Typical weather files are being generated using historic weather data, which represent past years. As, the Indian context, life span of the building is expected to be 75 to 100 years, it is expected to perform net-zero throughout the lifespan from the building. Hence future weather files are important to be looked at. IPCC has developed the weather scenarios for future climate. Based on these weather scenarios future weather files can be generated. While designing such futuristic buildings, in the building simulation future weather data could be one of the focus points. CARBSE is a net-zero energy building at CEPT University, Ahmedabad. That same is considered as the case study as a part of this thesis work. The building has recorded all the energy usage data from the year 2016 to 2019 for evaluation, as it is a living lab for building energy performance. This study starts with understanding and generation of future weather files. Secondly, comparing future weather files and typical files with the actual years for better understanding. Climate analysis and scope of passive strategies in future years are a major concern as the building uses such energy conservation measures to reduce cooling load. Building performance assessment and net-zero status check are done for the same weather years. If the building is not managing to maintain its status of net-zero, what are the reasons behind the same are looked at in detail? Refurbishment solutions for Envelope, HVAC systems and Renewables are proposed and evaluated by the cost as well. From all the above refurbishment solutions, a method can be developed to evaluate net-zero energy building according to owners’ perspective for energy and cost.

Abstract: Net-zero energy designs typically have incremental monetary costs due provision of elements like PV panels, efficient HVAC equipment, insulation, DGU windows etc. These materials and/or equipment translate to incremental embodied carbon as well. The annual performance evaluations do not consider this embodied carbon released before the use of the building. They also don’t consider the impact of deconstruction and disposal of the building. The annual savings of a building might not be able to compensate for these emissions. A net-zero energy status is thus, not sufficient to ensure savings in greenhouse emissions across the lifespan of a building.

The accounting of emissions can be done through a Life Cycle Analysis (LCA). The goal of conducting the LCA then is to quantify the amount of CO2 emissions that are to be extracted from the environment to reach an absolute zero carbon status. It opens possibilities of bridging the gap between net-zero energy and absolute-zero carbon for a net-zero energy building (NZEB) in India. This study looks at the quantification of the trade-off needed for an existing NZEB based on requirements of ISO 14040/44.

The data collection process requires spanning several reporting locations and published references. The consistency in data quality was achieved through the evaluation of data sources against indicators for type, age, geography and data units. The uncertainties in data and assumptions progress in the calculations and also affect the reliability of the results. The results of a Pareto analysis were used as a proxy for an uncertainty importance analysis. The uncertainty of the largest inputs was explicitly addressed to establish the accuracy of the inventory.

Once the trade-off is quantified, it enables the possibility of developing a business case to compensate for the emissions. The NZEB can target achieving a net-zero carbon status within a certain time. The gap between net-zero energy and net-zero carbon was calculated to be 2,619 tCO2e. The study results in an understanding of the sensitivities of a life cycle analysis towards the system boundary, data quality requirements and acceptable limits of uncertainty. The inventory developed for this study applies to any building constructed within Gujarat from 2012 to 2018. This can be used to scale up the research to create benchmarks and/or standards.

Abstract: The physics of heat transfer in a zone cooled with a radiant system differs from all air systems. In case of zone cooled with radiant system, heat is removed by both convection and radiation whereas in case of all air system heat is removed by convection only. Standard Cooling load calculation methods suggested by (ASHRAE, 2017a) standard considers overhead well mixed system and heat removal by convection only. In case of All air system, convective load instantaneously becomes cooling load, and the thermal mass of the zone first absorbs the radiative part of the load and later it is removed by convection to the zone air. Because of direct removal of some part of radiative load in case of radiant system, cooling load in case of radiant system is different from all air systems. Also, standard cooling load calculation methods consider a constant temperature setpoint for calculating cooling load which is not necessary for achieving thermal comfort. Standard cooling load calculation methods fail to identify this difference, and this has been identified by much literature. In this thesis, a survey of radiant system designers of 40-50 buildings was conducted to understand the current scenario of radiant system design in India. It was identified that most designers do not differentiate cooling load between radiant and all air system. Based on survey and literature study, 5 cooling load calculation methods were identified, and radiant system was designed using these methods. Assessment of radiant system for these 5 methods was carried out by simulations using DesignBuilder which uses EnergyPlus as simulation engine. A validated model from the literature study was selected for the analysis. EnergyPlus was used for simulations because it performs the heat balance for all the surfaces of the zone and conduction transfer function has been modified to include the heat sink/source within a surface and it can capture the transient behaviour of radiant system. The simulation results identified that the peak cooling rate in the radiant system was 46 – 68% higher than what was calculated using standard cooling load calculation methods. By designing the radiant system using iterative method using simulations, it was identified that up to 50% reduction in plant size was possible compared to standard design procedure.

Abstract: India — the second-most populous (1.37 billion in 2019) nation of the world (International Monetary Fund, 2021) - is anticipated to have the biggest population in the world by the year 2030 (UN, 2019). Concurring to the 2011 census information, India’s number of households was 246 million with a population of 1.2 billion (GoI, 2017). Under the 2011 average household measure (4.9) suspicion, there will be 307 million households in 2030.The floor area of residential buildings in India is evaluated twofold (16.0 billion sq.m to 31.6 billion sq.m) and the residential energy consumption is assessed to trifold (246 TWh/y to 748 TWh/y) between 2017 and 2030, as per NITI Aayog (2015). This development of residential floor space, combined with an increment in electricity production, leads to critical energy demand within the up and coming decades. Hence the significance of creating energyefficiency techniques & building energy-efficient residential buildings in India is fundamental (Rajan Rawal, September 2014).The purpose of the study is to assess net-zero energy potential for a proposed apartment building, suggest effective energy conservative measures, and see the financial achievability of the same by reporting the payback period and internal rate of return (IRR). The study will cover the economic feasibility of each energy conservative measure and the potential of photovoltaics at present state of art technology to combinedly achieve potential net-zero residential building.The study is conducted for a proposed G+12 apartment building located in Sonipat, NCR. The plug load data to calculate equipment power density is gathered by conducting a survey. The study also includes a 14 days comparison of simulated and measured indoor temperature results for a test room, energy-saving potential for Eco-Niwas Samhita form building as usual case,and its internal rate of return.After applying three different identified internal profiles (low-mid-high consumption) the BAU case EUI is in the range of 92kWh/m2-year to 88kWh/m2-year. ECM's - IMAC MM 90% temp. setpoints, shading, NV, efficient envelope, efficient PTAC system were identified as energy conservative measures (ECM’s). After all ECM's were applied one upon another the EUI is in the range of 37kWh/m2-year to 31kWh/m2-year (66% reduction from BAU case). Which gives a payback period of 8 months.A 73kWp of rooftop PV is installed which offsets 26 kWh/m2-year EUI with a payback period of 2.1 years. The ENS compliance case with a low payback period is found and this case has the EUI range of 69kWh/m2-year to 72kWh/m2-year (19% reduction from BAU case) which payoff from day 01 when used AAC blocks.

Abstract: Improving the energy efficiency of buildings is a key towards climate change mitigation strategy. Application of this requires upgrading the existing stock, a subset of this are buildings with historic importance. The study presents the thermal comfort and energy performance potential of building retrofits being carried out at Faculty of Architecture (FA) building at CEPT University, Ahmedabad. It is a building of modern heritage and has unique place in the history of modern architecture in India. The building also influences architectural teaching pedagogy in India and abroad. FA building was designed by B.V. Doshi in the year 1968 and was categorized as Universal Cultural Heritage in October 2017. It is being conserved as per the guidelines accepted by The International Council for Monuments and Sites (ICOMOS) and International Committee for Documentation and Conservation of Buildings, Sites and Neighborhood of the Modern Movement (DOCOMOMO). The structure is being upgraded in accordance with modern needs for comfort and environmental requirement. Retrofit of the heritage building has been carried out not only to reduce the energy consumption of the building but also to preserve the building for future generations. The study starts off by comprehending the trade-off between the heritage status of the building and energy efficient strategies proposed that addresses to the concerns of thermal comfort and energy conservation to support its round the year occupation. Workflow and approach followed for developing FA building energy model includes documentation of construction assembly, internal gain parameters, schedules, and system level details. The study commences by recording the Illuminance levels measured in various studio spaces and Glare Analysis for students and faculty members. This followed by study of the impact of night flushing potential on energy consumption for space cooling. A zone level comfort analysis comparison for pre and post restoration scenarios. Addressing the issues of thermal comfort and energy efficient strategies, ensures a healthy and sustainable lifestyle of the building occupants. The outcome of the proposal is a developed methodology for evaluation of post restoration scenario of a heritage building in terms of visual and thermal comfort, in Indian context. Also, this study can be further referred to monitor the intent of strategies proposed with actual building operations results.

Abstract: Occupant's interaction with external fenestration can have a large impact on the indoor environment and energy consumption of buildings. The increase in India’s residential cooling demand gives rise to the need for gaining a better understanding of mixed-mode operations in residential buildings.

This study explores the non-thermal drivers that inhibit occupant interaction with external fenestration, this is divided into three stages. Stage1: User window operation survey that reached out to 150 occupants to identify the non-thermal drivers that prevented the opening of windows during favourable outdoor environment. Stage2a: A field mapping study in which 10 residences were studied for a period of 5 days. The parameters monitored were temperature, humidity, CO2 and window operation status. Stage2b: An experimental stage to determine the window status by finding the air change rate through the tracer gas experiment. The experiment analysed the CO2 decay curves with various opening percentages, these curves were cross-referenced with the occupant-generated CO2 data to define the window status. To ensure the window status was accurately achieved multiple considerations were taken to maintain the occupant’s privacy.

Stage3: Simulation, assisted in identifying the ideal period for which windows could be operated. This established the possible energy saving by analysing the comfort hours. The whole building simulation model was created in design-builder to simulate the data collected on-site. The window operation schedule was fed into the simulation model and simulated for two cases, case one’s windows operation schedule was based on the differential temperature variation algorithm and case two in which the schedule was derived from the field study. In the study conducted in residential households, it was found that 90% of its residences the fenestration operations were under the influence of non-thermal drivers. This resulted in a 20% reduction in comfort hours.

Abstract: The design of active and passive techniques to manage the thermal comfort of the building occupants depends on the indoor design conditions (Temperature and RH). To recommend these indoor design conditions in Indian context, practitioners refer to standards like the NBC (National Building Code of India, 2016) which specify these conditions based on the building operation type (NV, MM and AC). However, the code does so by use of Indian Model of Adaptive Comfort which only specifies the Neutral Operative temperatures but does not specify the corresponding RH ranges for which it shall be applicable. This is so because it is an empirical model, and the RH data is built-in when it is derived. The specification of the same shall help the researchers and practitioners in applying the RH limits to the indoor comfort conditions specified for the spaces studied or designed. The Objective of the research was to include the RH signal into the IMAC thermal comfort equations. This was done by studying the open source published thermal comfort survey data (ASHRAE RP 884) through statistical methods like Griffiths Constant Method and Python based machine learning algorithms. The study resulted in definition of sensitivity of thermal sensation vote on change in indoor temperature in specific RH ranges and comparison of Neutral temperature so arrived with that predicted by IMAC model for all Naturally ventilated and Mixed Mode buildings. The study also resulted in specifying an updated prediction model for NV buildings with an RH range of 40 to 75 %. . This study shall apply to Indian conditions as the data utilized for the study shall be derived from the thermal comfort studies carried out in India.

Abstract: Lime plaster is one of the key sustainable building materials which is also effective as a passive cooling strategy. It is well known for its moisture buffering capabilities. In this work, the hygrothermal performance of lime plaster is observed through simulations and surveys. Surveys are carried out for 45 traditional buildings of Ahmedabad in India with measurements of ambient variables, such as temperature, relative humidity, wall moisture content, etc. In hygroscopic materials such as lime plaster, realistic conditions like mold growth cannot be predicted through simulations. The surveys carried out are the best examples to understand the circumstances of mold growth. And an attempt is made to use these readings and observations to predict the phenomena of mold growth in a space while conducting simulations. To understand this, an experiment is carried out where similar samples of lime plaster are exposed to different Relative Humidity from 75% to 97%. This information can be then correlated with the surface relative humidity plotted through simulations. Moreover, the Relative Humidity at which the mold growth initiates in a lime plaster can be derived. Using a combined approach of simulation, survey, and experiment it was possible to predict the mold risk of the space.

Abstract: This paper presents a methodology to calculate and plot operative temperature (Top) for naturally ventilated (NV) spaces at multiple points in a thermal zone both spatially and temporally. The proposed methodology calculates 3 environmental variables (air temperature, mean radiant temperature (solar adjusted) & air velocity) which affects comfort for NV spaces and bisects the workflow.
1. Thermal simulation: To obtain air temperature and surface temperatures to calculate mean radiant temperature.
2. Computational Fluid Dynamics (CFD): To obtain air velocity distribution.
Further, data from CFD & thermal Simulation is amalgamated and integrated with other calculation variables such as view factor & effective radiant field (ERF) to derive Tair, Tmrt & Air velocity (Vair). The weather data is binned for wind direction to optimize the number of CFD runs. The proposed method limits itself to iso-thermal airflow and hence accounts only for wind assisted ventilation. Top across thermal zone is calculated for grid points to generate point-in-time thermal plots. Further, Top across all the data points in space will be translated into a spatiotemporal representation for a given set of thermal comfort acceptability criteria which will indicate the percentage of time a grid point meets the comfort condition.

Abstract: A steep growth in the residential sector is expected as per the literature survey. Eco Niwas Samhita is a residential energy conservation building code which estimates the heat gain from building envelopes. In the available literature, nothing could be found regarding heat gain due to infiltration. Therefore, the thesis focuses on estimating the effect of infiltration rate on RETV. The study has two aspects, first being surveying 20 air-conditioned apartments and other being simulating 9216 parametric cases. It was observed that only 3 out of 20 residential apartments were under the RETV limit of 15W/m2. The blower door test suggested that the infiltration rate varies from 0.53ACH to 1.63 ACH. It was observed that the average infiltration rate is 0.74 ACH for aluminium sliding windows and 1.35 ACH for the wooden casement windows. The sensitivity analysis shows that the heat gain from infiltration can vary from 5% to 33% of the overall envelope heat gains. The Parametric analysis conveys that the heat gains from infiltration are as significant as that of walls. Lastly, infiltration coefficients are proposed for the revised RETV equation. The derived infiltration coefficients are 5.46, 4.22 and 3.53 for Hot-dry, Composite and warm-humid climate respectively.

Abstract: Solar irradiation has a huge impact on building energy consumption due to solar heat gains through the building envelope. Considering trees as exterior obstructions in initial calculation would optimise building energy efficiency. The challenge lies with the limited research on individual tree shade characteristics from a building modeling perspective. Therefore, a simplified methodology that would consider tree shade factors sans geometry without compromising on data accuracy for detailed energy estimation in various simulation engines is required. Site measured data through hemispherical photography and simulated results from Rhino honeybee and grasshopper are calculated in the workbook and presented as a Shading factor (SHF) schedule. Shading factor (SHF) is a possible solution to the above-mentioned challenge. It is defined as a fractional reduction in irradiation received over a building element due to tree shading. It is determined by finding canopy ‘Void ratio’ or ‘Transmissivity’ based on field parameters like canopy area, canopy density, tree species, tree location and orientation with respect to building element. Presently, no such study to incorporate native Indian trees as a passive measure in simulation engines is available. Therefore, this research study aims to propose a simplified methodology that includes factors such that it is recognized by various engines to ease the complex simulation process and reduce computational power.

Abstract: Daylighting is a globally available free resource which can be harvested for proper utilization by the use of daylighting systems. Venetian Blind systems provide sun shading, view to the exterior and have the potential to increase daylight performance of interior spaces when used effectively. Studies have shown a 20-60% increase in visual comfort performance when these systems are used efficiently. This research introspects the concept of a traditional venetian blind system, redefines the venetian blind design by segmentally splitting the blinds based on the concept of the Field of View (FOV) of the human eye and evaluating the improved blind design by the means of advanced daylight simulations. In order to evaluate the improved system, a three-phase simulation method was used, and the illuminance results were extracted from the simulations. The illuminance data was then filtered on the basis of conditions provided and respective credit scores were given for every blind combination for every daylit hour of the year. The study then identified the strategies with high credit scores that could be used to operate the improved blind system. The results show that the improved blind design has a significant improvement of daylight performance over the BAU case. An annual increase of 73.1% useful daylight hours was observed. Though the results observed significant increase of daylight performance, it was important to evaluate the control algorithm for its cost function implications and predict how much energy may be consumed due to the continuous operation of the blinds. Recommendations to calculate the cost functions are attempted in this study. Further to this, a study was conducted to check if a This research also aimed to identify if any set of blind positions changing through the day would work consistently across the year, and to evaluate the relative merit of such a strategy. While the solstice strategies performed poorly, the equinox strategy worked well, with a reduction of annual performance by just 2%. This gives the operator an option to use a single daily strategy to cater to the entire year with a negligible visual performance compromise at a reduced cost function.

Abstract: Building envelopes are the key components that distinguish the exterior and interior environments. Dynamic façades and fenestrations are used as an important strategy for regulating the entry of daylight as well as solar radiation into the workspaces. Ensuring effective use of daylight is a challenge as it is often overused and sometimes underused in a built environment. Design and construction as well as operation of fenestrations thus have a direct effect on the availability of indoor daylight. Several studies have also shown that a good façade design will improve the psychological and physiological needs, thus increasing the necessity for research in this field. In order to check the effectiveness of an adaptive façade an origami-based design is chosen. To enhance the daylight performance using the Adaptive facade, a 3-Phase Daylight Simulation is carried out for both equinoxes and summer and winter solstice for one location. An annual simulation is also done for three locations with equal latitudinal difference for three cases. The daylight simulation was carried out through Rhino software using Grasshopper and Honeybee Plus plugins with a Radiance interface to explore the applicability of parametric design to improve daylight efficiency. An appropriate control strategy was developed for the adaptive façade. It was observed that the use of Adaptive facade improved the overall performance but was mainly effective till a certain distance from the façade and was ineffective after 4.5m distance for both equinoxes and summer and winter solstice. A latitude difference of around 5 to 13 degrees has no clear difference on the implementation of an adaptive façade of this design and may depend more on the climate of the region with different cloud cover.

Abstract: India having a diverse climate, cannot accept a common and converging solution. In order to address the same, the study aims to reduce energy consumption by using a low energy cooling system. In order to understand the opportunity of change in cooling strategies, a thorough study of hybrid systems has been conducted in conjunction with the current scenario. The control program was designed using the EnergyPlus –energy management system. Sensor and actuator were used as an object to control the program in the model.Group simulation for all the 60 weather files were run and were segreagted into four climatic zones.The results show a reduction of 1.5-24% depending on their respective climate zone. The maximum reduction was recorded in Barmer and Jaisalmer with 24%. The minimum was recorded in Dibrugarh – 1.5%.With an advancement in the HVAC industry, the application of such systems can come into place. Observing the capability of the industry, the use of system along with sensors and actuators can be a way forward to the technology.

Abstract: The Pradhan Mantri Awas Yojana – Housing for All scheme aims at providing affordable houses to all eligible beneficiaries in India by 2022. Hence, with the increase in the number of households, the increase in energy demand is inevitable. Thus, there is a need to observe and analyse their energy usage along with their thermal comfort to address the growing demand. This study aims to identify the energy usage pattern and appliance penetration in affordable households along with the thermal comfort of the occupants. A field study was conducted in 20 affordable households in Chennai, which experiences a warm and humid climate. The study involved data collection like long-term monitoring of indoor air temperature, relative humidity, and energy consumption, background information of occupants, comfort assessment, behavior and energy usage, Right Here Right Now Thermal comfort surveys with questionnaires and instantaneous measurement using handheld instruments, building floor plan, observation of window and fan operations method, and the adaptive measures incorporated. The Residential Envelope Transmittance Value is calculated for all the houses and the relation between the building envelope and the indoor conditions is discussed. The study discusses the prevailing thermal comfort conditions in affordable households and the adaptive measures taken by the occupants to maintain their thermal comfort and their effect on energy consumption.

Abstract: This study is conducted to project the increase in energy consumption due to the change in floor area of residential and commercial buildings and how the implementation of the Energy Conservation Building Code (ECBC 2017) can limit this increase in energy consumption. The site selected for this study is the CBD of the city of Ahmedabad. Bottom-up approach is employed, which is using urban scale energy modeling (USEM). The study requires future weather files for each year of the decade until 2050. IPCC scenarios of higher emissions RCP 8.5 were used for the weather forecasts. The other projection concerned is the increase in floor area, which was taken from the existing development plan for the city of Ahmedabad, which had allowed a maximum FSI of 5.4 defined in Gujarat DCR for the CBD. To consolidate the energy consumption projections, historical patterns are observed, and for aggressive and moderate growth scenarios. The results obtained show that there is a fivefold increase in energy consumption in 2050. The scenarios developed with the susceptive approach towards energy consumption helps in identifying the energy-saving potential for each of these cases, thus providing flexibility in understanding the effects of each of them when applied individually.

Abstract: Today, the necessity of energy-efficient buildings is increasing continuously and along with it, understanding the electricity consumption in every aspect of these buildings has become important. Out of them, lighting systems covers up to 19% of the global electric energy consumption. Efficient use of daylight helps in reducing the consumption of electric lighting up to 20-40% which leads to energy conservation. If designing is carried out properly, attaining minimum glare factor, daylight can have advantages like reduced eye strain, falling stress levels, reduction of health problems and increase in productivity, which further leads to financial benefits to the organization as well as user satisfaction. The aim of this study is to analyse the daylight conditions and provide retrofit solutions to enhance daylight and reduce the energy cost of a 5 floored coaching institute, for higher secondary students located in Solapur city of Maharashtra state, India. The results of initial day lighting level simulations from LightStanza help to understand the scope of enhancement in this building. Thus, defining the spaces that need improvement. To analyse daylight conditions in these spaces, light levels are to be obtained/accumulated by measuring luminance through HDR imaging and in turn finding luminance-based illuminance. For this, a device is to be built which consists of a commercially available credit card sized computational device (Raspberry Pi) and a fisheye lens camera module. This HDR imaging device is then to be calibrated for various necessary correction factors. Studies show that this type of device provides an accuracy ranging from 5% - 20%. The illuminance levels from measured luminance are to be used to calibrate the simulation model in LightStanza and the generated results will be used for evaluation. After this evaluation, fenestrations need to be redesigned for enhancement of day lighting. These redesigned fenestrations along with other solutions will be implemented to one of the classrooms to measure the light levels to validate the study.

Abstract: India, as we know, is a rapidly developing country and is one of the most populated ones in this world. This is leading to a soaring rise in energy consumption and has shown a dramatic rise in the past decade. Of the massive energy needs of the country, energy for cooling and comfort is one of the most demanding sectors of consumption. Cooling is necessary as it directly implies to benefits of human development, health, well-being, and economic development (Agency, 2018; Angrisani, Roselli, & Sasso, 2013). India has projected growth in cooling demand of up to 2.2 times within the next 15 years (Ozone Cell, 2019). This demand is cooling needs to be addressed sensitively majorly because of the equally growing energy crisis as well as the weighted contribution of global warming and ozone depletion due to conventional cooling methods. Therefore, the right approach to satisfy this cooling demand of the country is to develop cooling technology with reduced energy consumption and reduced carbon emissions.

All buildings will have both latent and sensible loads. In conventional HVAC practice, the latent loads are very inefficiently treated. This results in a drastic increase in the overall energy consumption of the building. Considering the increasing annual carbon emission of 2% globally, the best way to treat these latent loads of the building is through non-refrigerant based methods. The solid desiccant technology has proven to be an impactful non-refrigerant based cooling technology that could help to efficiently cater to the latent loads of a building. This technology is a great and efficient addition/ replacement to conventional systems. But these systems are exhaustive and complex to set up and maintain. This has resulted in this technology to not be able to expand and flourish in terms of widespread utility even with its efficient benefits. Therefore, the thesis aims to make the solid desiccant system more market feasible by improving the operational efficiency of the system through developing sophisticated rule-based control algorithms. This work aims to impact the reduction of consumption as well as the improvement of the supply efficiency/ accuracy of the system.

The project is divided into 3 stages. The first stage is the modeling and simulation of the solid desiccant wheel under the EnergyPlus platform. The second stage is the derivation of the rule-based control algorithms from the physics-based first principal equations of a solid desiccant wheel. The final stage involves the implementation of these control algorithms into the EnergyPlus model through the inbuilt Energy Management System (EMS) and extract and analyze results.

There have been 3 cases created to compare the results of simulations. The first case being a conventional DX cooling coil AHU system attached to a single zone. The second case is a hybrid system of desiccant wheel + DX cooling coil with simple ON/OFF control logic (this is the most widespread control logic used for solid desiccant system). The third case is the desiccant wheel + DX cooling coil with the proposed control algorithm. The proposed control algorithms for the desiccant wheel system modulates 2 variables in the system. The two variables are the heater setpoint temperature for the regeneration side of the wheel and the mass flow rate of the balanced flow desiccant wheel for the process and regeneration side of the system.

The desiccant wheel + DX cooling coil hybrid ON/OFF system in comparison to a conventional DX coil system. The hybrid system saves up to 22.21 % of annual electricity consumption overall. The hybrid system also reduces the cooling coil size from 1.38TR to 1.26TR. Further, the developed control logic is implemented to the desiccant hybrid system and comparison is made. The desiccant hybrid system with the applied control logic saves up to -13.2% annual electricity consumption compared with the ON/OFF control system model. The cooling coil design size of the system is reduced from 1.26TR to 0.86TR.

Abstract: With round- the-clock use and high occupancy in hospitals, the indoor air quality of the critical areas along with the energy usage of the space (mechanical systems) to keep it running, is the most impacted. As the patient’s health is the most critical factor in an ICU, the need for maintaining a good indoor quality is of paramount importance. The ventilation system provided and outdoor ambient conditions directly impact the indoor air quality in the space. HVAC systems play an important role on the infection risk in critical and sterile spaces. ASHRAE Standard for prescriptive “ventilation rate procedure” and its performance-based approach of “indoor air quality procedure” (IAQP) help determine minimum Ventilation rates (VR) based on objectively evaluated indoor air quality (IAQ). The first primary goal of this study was to determine, in the intensive care unit (ICU, the adequacy of ventilation rates (through the existing HVAC system) observed through measurements in providing the level of IAQ specified through the IAQP process. The second goal was to evaluate whether VRs implemented experimentally would achieve adequate IAQ, assessed objectively & subjectively (although subjectively is for the future scope of this study) Mass balance models were employed to calculate indoor contaminant generation rate within the ICU. Using this model, the typical outdoor air contaminant concentrations, to calculate the ventilation rates that would maintain indoor contaminant concentrations below the selected REL. These VRs were compared to the measured and prescribed VRs in ASHRAE 170. An experiment is performed to check if by applying the IAQP to allow lower VRs in the considered zone, energy savings are possible whilst still maintaining acceptable indoor air quality. Based on the findings from applying the IAQP calculations and through an experimental performance optimization in the ICU, recommendations are made with regards to energy saving potential.

Abstract: Growing urbanisation in India has led to the increasing development of high-rise buildings. To maintain the building aesthetics, the outdoor air conditioner (AC) units are stacked within a recessed space. The heat rejected from these outdoor units (ODU) leads to an increase in air temperature of the recessed space. This causes inefficient working of AC units. The paper reports the difference in results when on-site measurement data were compared to CFD simulation results. The on-site measurements were taken for six storeys of an eleven-storey building. The different turbulence models were studied, and it was concluded that the NK turbulence model had the least percentage difference of 8.89% when compared to the site data. Further, NK model was used to study the placement of ODUs in recessed spaces having varying depth and width. When the horizontal distance between the ODUs increased by 1m, maximum condenser on-coil temperatures reduced by 6°C. The studies concluded that, even by allocating lesser area to the recessed space, but by optimizing the depth and width of the space, the temperature increase of the microclimate can be avoided and AC efficiency can be maintained.

Abstract: The perforated screen is an architectural element/device that helps to protect from direct sunlight, allows visual contact, and acts as a shading device. With the advancement in technology, various versions of shading devices are being used on building façade to reduce the impact of harsh sunlight. It is important to evaluate the simulation capabilities to quantify the performance of shading devices with complex geometries. The purpose of this study is to identify the daylight simulation method for a perforated screen, which can help to make design-based decisions at various stages of design. To understand the accuracy of simulation’s result this study compares two RADIANCE based simulation techniques with the actual on-site illuminance measured data. For the daylight simulation Rhino 6 (Robert McNeel & Associates, 2018) software with Honey Bee Plus, the plug-in is used to simulate through 2-phase and 5-phase simulation methods. To generate Bidirectional scattering distribution function (BSDF) data for the 5-phase method, WINDOW 7.7 LBNL (Berkeley Lab, 2015) software is used. In the second phase of the research process, annual simulations were performed to understand the impact of various parameters of the screen, such as thickness, geometry, and distribution of voids. Comparing the results of 2-phase and 5-phase simulation method with the actual measured data shows that the 2-phase method predicts around 30% error, and 5-phase results follow a similar trend as actual results with around 14% error in the results. Co-relating results of different thicknesses and geometry show that thickness has a significant impact on the daylight performance of the screen and geometry did not translate as a significant factor.

Abstract: This research aims to validate the existing and widely used glare metrics for Indian context, namely, Visual Comfort Probability (VCP), Daylight Glare Index (DGI), CIE Glare Index (CGI), Unified Glare Rating (UGR) and Daylight Glare Probability (DGP). Dataset is derived from controlled experimental set-up, where subjective evaluation of various luminous environment is conducted. High dynamic range photogrammetry was used for mapping the glare from LED sources. The luminous map data and participants subjective evaluation is compared against each other to evaluate glare metric. For the purpose of this study, robustness is defined as the ability of a metric to assess subjective glare perception for Indian context considering influence of various temporal variable such as effect of caffeine ingestion, previous luminous environment exposure and effect of fatigue using rank correlation and logistic regression analysis. The results exhibited high degree of scatter when subjective evaluation were compared against various glare scene pertaining to a scale of above mentioned glare indices. This scatter indicated that there are more variables that influence glare perception besides the commonly used, in the glare equation which needs to be accounted for. However, future work needs to be carried out to validate this research.

Abstract: The aim of this research is to create an integrated decision-making strategy for achieving Net Zero Energy in Varied Sizes of Office Spaces, by identifying strategies that are both energy and cost efficient. The proposed integrated design approach is applied to three varied sizes of high-rise office buildings; bifurcated as Small Office Building comprising of four-floors having 500m2 floor plate area, Medium office Building comprising 10 floors having 1500m2 of floor plate area each and Large Office Building having 20 floors of 2500m2 of floor plate area each, located in Ahmedabad. Energy simulations were done using Design-Builder software (Energy- Plus tool). The availability and cost of the materials and equipment were assessed with a market study.

The maximum energy savings achieved with prescriptive compliance through ECBC-Super measures as mentioned in ECBC-2017 for all three building types, having 20.6% savings for Medium Office, 17.6% for Large Office and 17.15% for Small Office type as compared to Business-as-usual case. The incremental cost and Net-present Value for all nine cases; i.e. three building type and three stringencies of ECBC-2017, were compared and, energy conservation measures prescribed for ‘ECBC minimum’ are the most optimum solution for all cases. Based on the impact of individual measures on all three types of buildings, the energy savings through Lighting Power Density is highest. It was also observed that, the impact of similar energy conservation measure of wall on Small Office Building was 2.44% greater than that of Large Office Building.

Abstract: Urban building energy models (UBEM) are important data-driven tools to support sustainable design and operations of cities, incorporating datasets from buildings and urban infrastructure. UBEMs are developed from a range of inputs on the spatial and semantic details of the buildings and the systems affecting their energy performance. Large geographical scales with finer Spatio-temporal details increase the challenges of data processing for a reliable UBEM. Thus, understanding the impact of increasing the Level of Details (LoD) of the inputs on the model outputs becomes essential. Adopting a ‘Fit-for-purpose’ approach leads to the appropriate use of the LoD having a suitable trade-off between the efforts spent on filling data gaps, model development, and the reliability of the outcomes. This research presents a framework identifying the LoD for the UBEM across occupancy, geometry, context to methodology, and calibration. A UBEM for 0.3 sq km of Ahmedabad, India is presented to support the same. The results highlight a need for a higher LoD in occupancy modelling for the residential and educational buildings, whereas a higher LoD is more important for the commercial building’s envelope characteristics. These insights become useful for developing a targeted supplementary data collection approach for the UBEM of the entire city.

Abstract: The building design community is challenged by continuously increasing energy demands, which are often combined with ambitious goals for indoor environment, environmental impact, and building costs. From an architect’s standpoint, the output results from simulation tools are mainly alpha-numeric charts that are difficult to use and interpret and are generally composed of enormous quantities of results data. These data have a huge potential for design improvement if communicated effectively. Poor data plotting limits the ability to compare, analyse and explore in depth to reveal hidden information, and thus leads to weak decision making. A robust literature review of data representation theory and past work in the development of the representation of thermal and energy simulation results was done. It suggests that there is a need to organize the already available fragmented efforts based on various design stages and design discipline. The methodology includes interviews with practitioners, analysis of current state-of-the-art spatial representations, selection of metrics, and developing the representations for a test case building. Based on the interviews and analysis of the current representations, a theoretical framework was proposed for energy efficiency visualizations. Further, a framework of representations which can be followed to represent energy simulation data to architects has also been proposed. This framework is a combination of representation of various options along x-axis, floors of the building along y-axis and representation of data for various metrics along the z-axis. This provides consistency in the representations, a background map that architects are familiar with so that data can be displayed for easy communication, and options can be compared. The results show not only that such representation can lead to a better understanding of the relationship between the building elements and its performance, but that certain metrics are more useful to stakeholders and combination or overlays of such metrics can lead to better understanding of design performance. This research is an attempt to bridge the communication gap between architects and energy modelers with energy information simulation results represented spatially.

Abstract: India’s energy demand is growing due to transforming economy. Lifestyle and consumption behavior is also changing with economic growth. Because of the accelerated economy, the country is urbanizing rapidly. Recent studies show that by 2030, India’s energy demand in the residential sector will be four-fold as compared to the energy demand in 2010. To reduce the future energy demand in the residential sector, the green building rating systems like IGBC, GRIHA, and LEED came up with design guidelines specifically for residential buildings. IGBC demonstrated savings of 30% to 40% on energy cost. However, research continually demonstrates that green building rating systems do not always ensure targeted energy performance and the way of identifying and addressing the performance gap is through building performance evaluation (BPE). This study was part of a project called Learn-BPE. This is UK- India research project which aims to undertake collaborative research and educational activities to develop the methodology to evaluate the actual performance of buildings from a technical and occupant perspective. This study reports the findings from BPE carried out on an IGBC green home platinum-rated building located in Ahmedabad, India. Monitoring and on-site measurements were carried out from 15th Jan 2019 to 28th Jan 2019. UK-BPE methodology was adopted for evaluation and through the case study, the methodology was evaluated to check its relevance and appropriateness for residential building in India. Annual and monthly energy consumption were analysed. PM2.5, PM10 and CO2 levels were monitored for indoor air quality. Thermal comfort and occupant’s satisfaction survey along with instantaneous measurements of indoor environmental variables were taken. Further, to understand the gap in UK-BPE methodology, a matrix was developed by comparing different rating system applicable to the residential building in India. This matrix helped in identifying the different performance metrics that are used by different rating systems in India. The rating systems considered for developing the matrix were IGBC green- (homes, affordable housing, residential societies), GRIHA- (v2015, existing building, affordable housing, SVA), LEED v4.1 (residential design and construction: multifamily core and shell, adapted for India) and Eco-Niwas Samhita 2018. The matrix helped in finding the gap in performance metric in UK-BPE and Indian rating systems and recommendations were also provided to fill the gap. This study was carried out to evaluate the UK-BPE methodology for residential green building in India. This study helped in understanding the requirements of green building rating system in India and helped in identifying the gap in UK-BPE methods for the Indian context. An extensive study was done for identifying the gaps in methodology and suggestions are given to bridge the gap. To evaluate the performance of the building, UK-BPE methodology was used and the project chooses a prescriptive approach for compliance. The building studied was located in Ahmedabad and its performance was evaluated based on the performance goals as per IGBC green homes and suggested methodology. After analysing all the aspects of case study building, it was found that building was performing and built as per the IGBC criteria requirements, but still there was gap observed in the operation and design due to which occupants were not using them as intended or do not help in energy savings. From the building study, it was concluded that evaluating criteria based upon prescriptive approach alone cannot determine the performance of the building, proper monitoring of that parameter needs to be done to know the actual performance of the building.

Abstract: Earlier studies have used Thermal Autonomy (TA) and Residual Cooling Degree Days (RCDD) to estimate the cooling potential of passive cooling techniques. But the cooling energy reduction due to passive strategies was not quantified. The BQEET tool uses the TM41 CIBSE method based on Cooling Degree Days (CDD) to calculate the CDD values using the appropriate Balance Point Temperature (BPT). The tool then estimates the reduction in cooling energy consumption due to passive strategies. This tool is targeted to help architects and designers to select suitable passive strategies in the early design stages. It is also targeted to help planners and policy makers to estimate energy use and cost savings at a large scale, to formulate and implement new policies. Limited testing of BQEET was done by Desai, using the ASHRAE Guideline 14 and IPMVP, since a robust procedure was not within the scope of the study. The Guideline 14 and IPMVP methodology are intended for calibrating the results of a simulation with an existing building and not for testing a simulation software. Hence, there is a need to test the BQEET tool in a robust way. The comparative testing in this study has been carried out for two types of buildings, air-conditioned and mixed mode building operating with passive cooling strategies. The testing procedures start by using the HERS BESTEST models of typical US buildings and modifying them using reference building models for the Indian context. There are no procedures for mixed mode buildings in HERS BESTEST, and no reference models for mixed mode buildings have been developed for India. Therefore, this study defines the mixed mode operation cases and tests them for the number of discomfort hours. The air-conditioned cases are compared for their energy end-uses. The lighting and equipment energy in BQEET are similar to the EnergyPlus results. But the cooling energy in BQEET is 400% higher than that of EnergyPlus. In order to analyse the variation in the cooling energy results, a critical analysis of the components contributing to the cooling energy is carried out. A building physics investigation of the cooling energy calculations of fabric gain, solar gain, fan gain and latent gain due to infiltration and occupancy has been carried out in the TM41 CIBSE method based on Cooling Degree Days, EnergyPlus and BQEET. The errors in the cooling energy calculations of the BQEET tool are identified, quantified and analysed. Modifications in the algorithm of the tool or in the BQEET tool itself are proposed.

Abstract: In India, the energy end-use is anticipated to increase by 56% from 2014 to 2050. It shares 12% of total carbon emissions in the world by Room Air Conditioners (RACs). As increase in energy production using fossil fuels has an adverse effect on climate, there is an immediate need to focus on mitigation scenario. This scenario counts on the change of refrigerant, improvements in system design efficiency and operational approach. Growth in urbanization and rising income is persuading the use of RACs. Seasonal Energy Efficiency Ratio (SEER) is the most used method to quantify efficiency of RAC. Environmental impact of the system is still unexplored. This study is conducted to develop a correlation between indoor comfort temperature, the energy efficiency of RAC and total carbon emissions (direct & indirect) considering its life span. Even with constant improvements in the energy efficiency of RAC using low GWP refrigerants, there is gap observed between the actual performance of the system and total emissions leading to climate change. The purpose of this study is to correlate annual cooling energy demand (w.r.t. comfort set-point temperatures) to energy efficiency and total emissions by a RAC for any city in India. The study was conducted in four stages - literature study, data collection, calculation methods and results. Initially, relevant metrics were identified from past work to quantify the parameters. In the next step, 12 Indian cities were selected based on GDP growth followed by Cooling Degree Days (CDD). Four RAC units were selected based on findings from market survey of 282 RAC systems available in the country. In the third stage, Indian Seasonal Energy Efficiency Ratio (ISEER) and Cooling Seasonal Energy Consumption (CSEC) were calculated for 12 cities using ISO 16358-1 and outdoor temperature bin hours. Carbon emissions were calculated using Total Equivalent Warming Impact (TEWI) score which comprises of direct (refrigerants) and indirect (energy consumption) emissions considering its life span. A method was proposed to calculate ISEER and CSEC using adaptive setpoints with few research gaps identified. The adaptive setpoints were calculated based on Indian Method of Adaptive Comfort (IMAC). Lastly, the results obtained shows that indirect emissions dominate in TEWI score which is calculated using CSEC (kWh). A more significant variations were observed in CSEC in different cities and different comfort models as compared to RACs with different ISEER. This study develops a methodology to calculate ISEER beyond BEE standard method and propose CSEC as a metric for different cities and different comfort models using indoor setpoints. The direct emissions were observed constant in all cities, the variations observed was because of indirect emissions (kWh). Thus, there is need to focus more on CSEC (kWh) than low GWP refrigerant to reduce total carbon emissions which causes climate change.

Abstract: ‘Housing for all – 2022’, a large-scale housing initiative was launched in 2015 by the Indian government for providing quality affordable housing to the lower economic segment by the year 2022. Occupant thermal comfort is one of the significant aspects of liveability and applies to affordable housing as well. These houses have low energy consumption as of now, however, as incomes and comfort expectations increase, energy use and related costs in this segment are expected to surge. Comfort field studies in affordable houses in India remains a subject largely neglected. This report discusses the findings of the thermal comfort conditions and energy use of 20 houses in three affordable housing developments located in Ahmedabad, India. The results discussed are from data collected using three methods. These involved long-term monitoring of household energy use and indoor environment parameters (air temperature and relative humidity (RH)), instantaneous measurements of thermal comfort conditions (air temperature, RH, air velocity, globe temperature) and right-here-right-now thermal comfort surveys. It was observed that average daily energy use ranged from 0.5 - 6.75 kWh and was dependent on appliance ownership and occupant behavior. Energy use was base load driven in these houses. 65% of the occupants reported being comfortable in their thermal environment during the survey period. The conclusions from this study give an insight into the seasonal and daily usage patterns of energy use in the affordable housing segment and potential for savings. It also discusses the prevalent thermal comfort conditions and adaptive measures adopted by the occupants.

Abstract: The commercial and residential sector demands high cooling requirement, which is mostly achieved by using conventional cooling systems like split ACs, chillers or VRF. These systems currently produce 100 MT of CO2 per annum and hence contribute significantly to carbon emissions. To mitigate such environmental impacts, using low energy cooling systems like an indirect-direct evaporative cooling system (IDEC) is an energy efficient alternative as it uses energy only for pumping water and blowing air. The evaporative cooling technology works on the principles of heat and mass transfer between air and cooling water. Direct evaporative coolers (DEC) works based on mechanical and thermal contact between air and water, while IDEC works based on heat and mass transfer between two streams of air, separated by a heat transfer surface with a dry side where only air is cooling and a wet side where both air and water are cooling (Porumb, Ungure, Fechete, Alexandru, & Mugur, 2016). As the capacity of air to absorb vapor is directly related to its humidity, evaporative coolers are most suitable for regions where high temperature coincides with low air humidity. It can cool air using much lesser energy than vapor compression techniques. This study evaluates the cooling performance of IDECs. The study was conducted in the industrial food processing unit where 61,800 CFM IDEC system is serving 465 m^2 of area. Internal loads are very high owing to the usage of gas furnace and fryers for cooking activity. The wet bulb effectiveness (WBE %) was calculated from the hourly measured values of air temperature (Ta °C) and relative humidity (RH %). These parameters were measured at inlet and supply air. Energy consumption of the IDEC system, air blower fan, and water pump were monitored every hour. Thermal comfort surveys were conducted in the space being served by IDEC. This was done to establish a relation between the system effectiveness, the cooling energy consumption and degree of occupants’ comfort. It was found that IDEC was able to achieve ΔTa of 5- 6 °C, saturation deficit of 30-35%, water consumption of 62.0 lit/hour with an average COP of 5. During August-October WBE varied from 55-83% with an energy consumption range of 29-30 kWh. Whereas, for November-December, WBE varied from 41-67% with energy consumption range of 23-28 kWh. However, despite this high WBE, 71% of the subjects voted the thermal environment to be either “slightly warm (+1)”, “warm (+2)” or “hot (+3)” on 7-point thermal sensation scale and 78% of the subjects wanted to be cooler. On further investigation, it was found that the IDEC was only able to produce 44,743 CFM whereas it was designed for 61,800 CFM. This could be because the system maintenance hasn’t been done for a long time. However, if the IDEC achieved designed airflow then the possibilities are that the WBE might not vary much, but an additional 27% airflow might help counter the heat generated by the cooking process. Also, the system might be able to satisfy the occupant thermal comfort expectations

Abstract: Natural Ventilation is one of the passive strategy for maintaining the occupant’s thermal comfort through fresh outdoor air. It also helps to reduce building energy required for space conditioning. The ventilation of occupied building spaces has two main purposes: one is to provide acceptable indoor air quality which is primarily based on the supply of fresh air and the removal or dilution of indoor pollutant concentration; the other is to provide thermal comfort to the occupants. In today’s scenario, people spend most of their time in indoor environments such as home or offices. Indoor contaminants like volatile organic compounds and stale air cause health problems and results in the so-called sick building syndrome. Naturally ventilated buildings provide adequate ventilation rates consistent with acceptable indoor air quality. Evaluating ventilation performance of a building is challenging due to the difficulty in prediction of indoor air movement under varying outdoor climatic conditions. In this context, water-table acts as effective tool for predicting the ventilation performance of buildings. A water-table is an inexpensive apparatus which may be used to predict airflow patterns for wind-induced unidirectional air flows. It is observed in literature that most of the water-table studies are based on qualitative analysis. Recently, a methodology for quantification of flow patterns generated in the water-table apparatus has been reported. This study involved water-table study with three basic configurations along with complex multizone apartment. Different ventilation metrics were developed for analysing the flow patterns. However, the effect of model scale on the derived ventilation metrics was not considered in this work. This is also observed with other studies in the literature. In view of above, this work focusses on estimating the limiting size of a scaled building model with respect to the water-table apparatus. Different configurations with openings on single side (SS), adjacent side (AS) and opposite side (OS) are studied using model scales ranging from 1:20 to 1:80. It is observed that model scales from 1:20 to 1:60 followed the same trend in terms of the evaluated ventilation metrics. Significant variation in results in terms of ventilation metrics are observed for model scales 1:70 and 1:80. Additional experiments are also carried out to study the effect of speed and aspect ratio. The findings of this research could be useful in selection of appropriate scale for conducting water-table experiments.

Abstract: With a growing awareness of energy efficiency in the hotel industry by the Indian government and hoteliers, energy performance is becoming an increasingly important aspect with India’s emergence as a global tourism hub. Energy audit studies conducted by local agencies and the Energy Department of India shows that hotels have a potential of reducing 20-30% of energy use without compromising the quality of hospitality services. For a correctly sized HVAC system complemented with an airtight envelope can help in substantial energy savings by reducing cooling demands.

In this work, air leakage characteristics of 30 air-conditioned double occupancy hotel rooms in Ahmedabad are studied. The studied dataset compiled consists of 18 rooms with split ACs, 9 rooms with central ACs and 3 rooms with window AC unit. These hotel rooms were tested using blower door method (pressurization/depressurization at 50 Pa) to find out their leakage characteristics. To check the airtightness of a hotel room blower door method is a quick and economical method. Relatively quick and accurate results are obtained by blower door. This research work adopts blower door method to measure leakage characteristics. The test results obtained at 50Pa are automatically converted in the form of effective leakage area (ELA) normalized at 4Pa just after the test is completed. The ACH due to infiltration is then modelled using simulation software for the respective geometry to find energy impact and potential financial savings.

The work was able to identify the correlation between ACH due to infiltration and multiple varying envelope characteristics like WWR, floor area, HVAC systems, window frame and tariff. The measured ACH due to infiltration for the rooms compared with the international standards for airtightness. Majority of the rooms were found to be airtight as compared with the most stringent standard. Factors such as window perimeter area and type of window i.e., fixed and operable for leaky hotel rooms helped in minimizing the infiltration. However, making the room airtight by compromising the outdoor view. Low tariffed rooms with split systems are airtight due to low WWR of typical 22%. Higher tariffed hotel rooms with centralized system were observed to be airtight. These rooms were newly built with bigger floor areas. For the hotel rooms studied, simulations show that the impact of air leakage on energy consumption is not substantial

Abstract: Retrofit of naturally ventilated educational building is an effective solution to the thermal and visual discomfort problems of the occupants. The Aga Khan Academy is a residential school, located in outskirts of Hyderabad, India. The school functions in an International Baccalaureate (IB) Curriculum. The building is IGBC platinum rated. The project deals with the retrofit procedure of the Senior Academic Block, which is naturally ventilated. The procedure contains steps: First, assessment of the existing conditions through climate analysis, thermal images, measurements & occupant surveys. Second, presenting retrofit design proposal and further optimizing and prioritizing scenarios based on thermal and daylighting simulations. The tools used for the analysis are: EDSL TAS and LightStanza.

The methodology is divided into four phases. The procedure involves: Assessing the existing conditions through climate analysis, measurement of surface temperature, indoor dry bulb temperature, humidity, daylight levels & occupant surveys; Developing retrofit options and testing them out using simulation tools: EDSL TAS & LightStanza, to quantify their impact on occupant thermal and visual comfort.

The measure taken include passive strategies related to the existing building envelop and addition of a low energy cooling system. Another aspect of this project is to enhance the daylight levels inside the classroom to provide occupants with a blind and glare free environment. The strategies that are recommended for enhancement of thermal and visual comfort are:

- Insulation of Aluminium Panel using 10 mm PU board insulation which achieved 40% comfort hours

- Adding horizontal louvers with slits in between on the windows facing west direction with achieved 50% comfort hours.

- Replacing Pinhead security glass with clear glass which helped to achieve 53% comfort hours along with sDA300/50 is achieved for at least 55% of the space & ASE1000/250 of no more than 10%.

- Converting fixed windows to operable windows which operate to 100% of the opening area in the main windows for ground floor and the clerestory windows combined with top and mid pane has 100% operable area on the first floor. This strategy helped to achieve 65% comfort hours.

- Adding a low energy cooling system – BreezeAir Evaporative Cooler to all the classrooms in a centralized manner helping to achieve 77% comfort hours.

Abstract: India is experiencing urbanization at a faster rate, majority of building energy is consumed by cooling, ventilation through fans and artificial lighting. Daylighting can be a key driver in conserving energy with saving potential up to 45%. It has the potential to cut energy use, reduce peak demand, reduce the cooling energy costs and create a comfortable indoor environment. As per ECBC 2017, the lighting power density (LPD) for a workshop facility is 14 W/sq. m, which is second highest out of all the LPD requirements and can have high lighting energy use. This study evaluated the daylight performance by calculating the potential lighting savings and assessing the visual comfort of the newly built workshop building at CEPT University, Ahmedabad, India. This study included measurement of illuminance and surface material characteristics, lighting usage patterns, a calibrated daylight model, and annual simulations using LightStanza (A cloud based daylighting simulation software powered by Radiance). The daylight model was also used to quantify the impact of important design decisions in the building. The calibrated model of the building has a RMSE (root mean square error) of less than 4%. The workshop building is LEED v4 and ECBC 2017 daylight compliant. In terms of glare related visual comfort, it faces no shading or harsh sun issues for most of the year but the spaces are likely to experience glare issues between 5-6 PM during the summer months. If the workshop building is operated as per the existing lighting pattern and usage, it will achieve cost savings of Rs. 86424 annually in lighting energy consumption when compared to the building that has lights on for all occupied hours. However, the building is likely to achieve more lighting energy savings with automated controls.

Abstract: Today, most of the people spend 80-90% of the time indoors either in the office or at home. Indoor air is contaminated by human activities and building materials like paints, furnishings, adhesives which emit volatile organic compounds. Exposure to these compounds has a short and long-term impact on health. Inadequate ventilation also causes Sick Building Syndrome. It is therefore important to provide the healthy indoor environment, as it has an impact on the productivity of people. Acceptable indoor air quality can be maintained by operating a building in natural ventilation. However, predicting the performance of naturally ventilated buildings is challenging, as the parameters governing the airflow, such as temperature and wind, are highly variable over time. Water table is an apparatus that helps to analyze natural ventilation in buildings due to wind effect. It is inexpensive, easily accessible and provides instantaneous two-dimensional results of airflow patterns in and around the building. The current research focuses on quantifying the qualitative data available from the water table experiment and developing ventilation metrics to quantify air movement within a physical building model simulated in the apparatus. The quantitative results of the algorithm will help to make design decisions in terms of opening sizes, orientation, and appropriate positioning of openings in the building. This will be of utility for educational purposes, serving architects, energy consultants and practicing engineers. The ventilation metric and the algorithm quantify the visual data from the water table and will assist in arriving at design solutions optimized for wind-driven natural ventilation.

Abstract: The revised version of Energy Conservation Building Code (ECBC) was published in June 2017 after ten years. The new version of ECBC goes beyond minimum compliance, and has two additional levels of ECBC ‘plus’ and ‘super’. ECBC includes a prescriptive compliance path and alternative Whole Building Performance (WBP) compliance path with energy use intensity ratios. This thesis assesses the energy savings and payback period for the prescriptive versions of ECBC-2017, minimum compliance, plus and super levels for an office building in Vishakhapatnam. It also demonstrates alternative cost optimized solutions for these three levels of ECBC using the WBP approach.

The office building is a real building in design stage according to the current construction trends that do not comply with even the previous ECBC version of 2007. Energy simulations are done in eQuest DOE 2.2. The availability & cost of equipment and materials to achieve the ECBC 2017 levels is assessed with a market survey.

Using the prescriptive compliance approach the ECBC, ECBC plus and ECBC super version of the office building in Vishakhapatnam, the energy savings achieved are 17%, 25% and 33% respectively as compared to the base case current practice building. The incremental cost (₹/m2) for these are 845, 1229, and 1454 and the payback periods are 4.3, 4.3 and 3.9 years respectively.

Using the Whole Building Performance approach, it was possible to achieve the compliance of ECBC, ECBC plus and ECBC super levels with much lower incremental cost a compared to the prescriptive version. The energy savings achieved for these bundles for ECBC minimum, plus and ECBC super are 17%, 29% and 38 % and the net incremental cost (₹/m2) are 87 ,292 and 429 with payback period of 0.4, 1 and 1.3 years. Based on the results of the individual measures considered in this study and current technologies available in the market, this study demonstrates an opportunity to achieve energy savings higher than the ECBC super level. Incorporating such measures will yield energy savings higher than ECBC super levels, and such measures could be considered in the design of Net Zero Energy buildings.

Abstract: Building energy simulations are used for carrying out detailed calculations for the energy use prediction of the building. A building comprises of several load components like people, equipment, electrical lights, HVAC systems, walls, roofs and fenestrations. Several studies in the past have shown that the fenestrations account for significant heat load increment in the building. The heat gained through fenestrations in the building can be identified through simulations. To accurately predict the heat gains through fenestrations, details of the fenestration like window opening size, the glazing material, window frame material, window frame size, shape and size of the shading devices are given as an input to the simulation engine. Also, the other important inputs for the glazing are the U-value and the solar heat gain coefficient (SHGC) of the glazing material. The SHGC value considered in the simulation is typically that is provided by the manufacturers. This values are derived under standard testing conditions prescribed by associations like the National Fenestration Rating Council (NFRC). And, the shading devices are additionally modelled to identify the impact of solar gain. However, there are different calculation methods that take into account the effects of adding shading devices and provide combined value of SHGC. This is done by taking into account the manufacturer’s SHGC value and the dimensions of shading device used. This gives an effective SHGC value that can be considered as an input to the simulation without modelling the shading devices. Two of such methods are studied in this research and compared with the simulation results. The impact of SHGC value through two different methods are studied in terms of solar gains (kWh) through fenestration and cooling energy. The results are also compared with the results of the simulation model in which the shading devices are modelled and the manufacturer’s SHGC value is considered instead of effective SHGC value. Further, the impact on cooling energy reduction is determined and compared for different latitudes, climates and overhang depth. The results show that the cooling energy reduction obtained from the methods with detailed heat transfer mechanisms are closer to the results obtained from the simulation with the physical shading device. Therefore, the generalization of the SHGC formula in the other method is not appropriate.

Abstract: The aim of this study is to demonstrate the impact of inside surface PCM application on walls of an office building, towards reducing the overall energy consumption, improving the thermal comfort and analysing the cost benefit potential. The office building is a G+2 floor building, which operates at change-over mixed mode on a seasonal basis. It is located at Ahmedabad, which has hot and dry climate. The heat transmission characteristics of the wall with inside surface PCM is analysed, along with added external XPS insulation, by using the testing facility of Guarded hot box. These experiments are carried out as per the ASTM C1363-05 standard test methods. Simulation software: design builder v4.7 and energy plus v8.3 are used for the whole building analysis. Three combinations of wall assemblies are analysed – internal surface PCM, internal PCM + external XPS and external XPS. The simple payback period of the PCM is calculated using the excel tool.

Experimental setup of the guarded hot box validated the PCM operation and effectiveness as envelope component and demonstrated a time lag of almost 9 hours when PCM is used.

In case of PCM with melting point 29, the latent heat stored by the thermal mass of the walls is gradually released, leading to the formation of a more stable indoor environment, while in the outdoor environment extensive temperature fluctuations exist. Software simulation analysis showed decrease in cooling energy consumption by 1.54%, The addition of external insulation in combination with internal PCM is increasing the energy savings to almost 4.02%. There was 4% increase in comfort hours (using adaptive comfort model definition) when compared to the baseline buildings with PCM installed at a hot and dry climate of India. Simple payback period calculation is resulting in high payback period of 28 years for PCMs, which can be reduced to 17.5 years combining it with insulation.

Abstract: The study aims to develop indices to assess the potential of passive cooling strategies for a climate. Cooling accounts for 40% to 60% of summer energy demand in metropolitan cities with hot climates like Delhi, & air-conditioner (AC) sales in India are growing at 30% per year (CEM, 2014). Recommendations based on current climatic zone may not be appropriate as many microclimatic conditions and variations are found in few kilometres range. The currently available climate analysis tools do not explore the inter-relationships between climatic parameters such as dry-bulb temperature, dew point temperature, wind velocity and cloud cover. Earlier work showed that it is possible to develop a weather-data-based classification to map the potential of some basic passive design strategies, such as building orientation, layout, plan, window-wall ratio etc. This study takes that approach forward to establish weather-data-based indices for strategies such as evaporative cooling, comfort ventilation, radiant cooling, earth cooling, and night ventilation. Weather data variables are identified for each strategy. This study uses adaptive thermal comfort models to represent the expected indoor comfort conditions. Typical Meteorogical Year (TMY) weather data of 59 Indian cities are analysed to develop the indices. Thermal Autonomy and Discomfort Degree Days are the metrics developed to measure the potential of the passive strategies. An Excel processor and a Power BI user interface tool have been developed. These enable the user to compare the potential for strategies within a climate and compare different locations for their climatic potential for a strategy. This work can be extended to develop climate zone maps that highlight the potential for specific low energy solutions in a region.

Abstract: Low energy cooling systems are designed to consume less energy while providing adequate comfort levels. A report by the Global Buildings Performance Network (GBPN) states that data used for simulation modelling is quite inaccessible in India. It also states that for accurate assessment of potential savings, good amount of reliable field study data is required. This paper evaluates two non-refrigerant based cooling systems with such field study and experimental data for thermal comfort and energy consumption in hot and dry climatic location in India. As a representative location of this climate, experimentation and simulations are done for the city of Ahmedabad. The systems studied are a direct evaporative cooling system and a 2-stage evaporative cooling system. In-field measurements and readings taken in the month of March were used to determine the experimental performance of the system. Energy consumption data inputs were fed into the thermal model of an office building which was modelled as per draft version of Energy Conservation Building Code (ECBC) India. This was performed in DesignBuilder and EnergyPlus combination for comparative performance over a baseline case. This baseline office case was served with a VRV system. Energy consumption savings and thermal comfort observations were reported over this baseline case of simulation model. A long-term thermal comfort survey based on previous perceptions of comfort from 16 occupants served by each of these systems was also reported for understanding. The EPI as a result of cooling through VRF, DEC and 2SEC is 89, 54 and 55 kWh/m2.yr which comes to 40% energy savings in both evaporative cooling cases. The hours not met were 505, 839 and 848 for VRF, DEC and 2SEC respectively. In terms of comfortable hours, DEC meets setpoints better than 2SEC. However, in the broader context, even with cooler effectiveness of 1, the evaporative cooling system does not have the capacity to meet setpoints. i.e has high unmet hours. If a building owner is interested in providing minimum comfort conditions and is in favorable of adaptive thermal comfort, evaporative cooling system can be installed. DEC can be the first priority as it does not have the complexity of installation like in 2SEC and initial cost is also not as much as 2SEC. However if providing comfort to occupants is the main goal and setpoint requirements are stringent, then evaporative cooling systems –both DEC and 2SEC are not suitable for office buildings where internal loads are very high.

Abstract: The potential of cooling with natural ventilation and forced ventilation demands attention and scientific study in order to 1) cater to the need of the larger portion of the population; those who cannot afford to air-condition 2) in order to reduce India’s energy consumption and reduce its greenhouse gas emissions due to space cooling demands. Ventilative cooling refers to the use of natural or mechanical ventilation strategies to cool indoor spaces using outdoor air. The most common ventilative cooling technique is the use of increased ventilation airflow rates during cooler outdoor periods, and night ventilation, but other techniques may also be considered. The effectiveness of Ventilative cooling is dependent on the availability of suitable ambient conditions to provide cooling to space. The objective of this study is to evaluate the benefit of harnessing the cooler ambient air to remove heated indoor air by using ventilation. The aim is to enhance indoor temperatures without resorting to more energy intensive methods such as air conditioning. The thesis attempts to provide a scientific basis to architects and building designers in understanding the benefits and limitations of natural and mechanical ventilative cooling in a typical set of residences located in hot and dry and temperate climate. The knowledge can guide designers towards incorporating ventilative cooling strategy as part of the building design when appropriate. The ventilative cooling benefits are calculated primarily using simulation tools. Further, the study also includes results from field measurements for short-period carried out in an apartment building to compare the results with the simulation models. Benefits in indoor air quality due to natural ventilation is not in the scope of this research. It is concluded from the study that adding ventilating cooling using natural ventilation in a typical residential apartment provides 5-43% increase in comfortable hours for two climate zones of India as compared with free running building. Ventilative cooling with mechanical ventilation provides significant comfort benefits (14-25% as compared to ventilative cooling with natural ventilation) and is beneficial to incorporate in residential apartment buildings in two climate zone of India. When compared to mixed mode buildings with no ventilative cooling, ventilative cooling can reduce thermal load of the apartment by 4-14% and 24-34%. While ventilative cooling is more effective in temperate climate, significant benefits can be achieved even in hot and dry climate of India during night periods. A novel method to continuously measure ventilation rate is developed for affordable yet accurate measurements. the measurements reinforced findings from the simulation results that ventilative cooling can provide significant benefits.

Abstract: The aim of this work is to study the technical potential resulting from the integration of evaporative cooling (direct, indirect and combined) with a mechanical cooling system. This work is limited for the small day-use office space in hot and dry climate of India (refer Annexure - A).

For this purpose, an office space (in Ahmedabad) was identified for which access and architectural & air-conditioning drawings and AC system details are available. Envelope, shading, adjacencies, internal gains, operating schedules, ventilation rates are studied. Base Case model was derived with appropriate changes for year-round mechanical cooling. Annual consumption, peak demand, cooling system size are derived for a cooling set point temperature (CSPT) of 25.5°C using simulation software.

Evaporative cooling strategies like direct evaporative cooling (DEC), indirect evaporative cooling (IEC) and their combinations (IDEC) are simulated with and without mechanical cooling system. Ideal evaporative air flow rates (to meet the cooling loads) for integrated system are found out. Effect of keeping DEC switched off during humid months and during morning hours in winter months are studied. Effect of using IEC for three humid months and using DEC in remaining nine months of the year is also studied. Finally, Simulations for potential of sensible heat recovery device is also explored in this study.

Evaporative cooling systems can be integrated with mechanical cooling system in many combinations. For the similar thermal comfort, hybrid system of mechanical cooling with DEC, IEC and IDEC help reduce VRF cooling system size by 29%, 20% and 38% respectively. HVAC energy is also reduced by 17%, 12% and 26% respectively. Similarly peak HVAC power is also reduced by 21%,12% and 27%.

Use of heat recovery device is justified in case of mechanical cooling only. Heat recovery devidce help reduce mechanical coolical cooling system by 31%, HVAC energy by 7% and peak HVAC power by 15%

Abstract: The thesis is on lighting retrofit of CEPT University located in India. The research aims to reduce energy consumption and enhance visual comfort of the university. The assessment of the spaces included lighting audits, monitoring of lights, schedule of usage, visual comfort surveys and measurement of illuminance levels. At CEPT University, electricity consumption due to artificial lighting is estimated at 32% of the total due to usage of spaces during the night. Health issues like headache, stressed eyes, glare, and low illuminance levels resulted in more than 50% of the occupants taking breaks for eye recovery. This thesis limits the scope to provide retrofit solutions to meet the requirements of NBC and ECBC for studio, classroom, and private office using the UFC recommendation where appropriate. These three space types contribute to 86% of the lighting energy of the campus. Retrofit solutions were proposed to address the issues identified in the audits and surveys, using technologies from a market survey. The proposed solutions included, lamp sources, fixtures, fixture layouts, interior surface modifications, switching and controls, and task lighting where applicable. These solutions were evaluated for light distribution using Relux lighting simulation software and for cost-effectiveness with a simple payback analysis. The energy savings due to the proposed retrofit are 21%, 44% and 42% for studios, classrooms, and private offices, and the simple payback due to is found 9.5, 3.8, 6.8 years respectively. If all rooms of these 3 space types are retrofitted (67 out of 122 spaces on campus) with the solutions identified, it would amount to an annual energy cost saving of INR 178,670 and annual energy saving of 19,852 kWh for an aggregate payback of 8 years.

As a result of urbanization, more than half of the world’s population lives in urban areas. This makes secure and efficient energy a global concern, most importantly at the municipal level. Storm water management consumes a considerable amount of energy, as a significant part of energy goes in pumping stormwater runoff out of the city or in a waterbody within the city. Hence, it becomes necessary to assess the amount of energy consumed in this municipal service by understanding all the factors responsible for energy consumption. This study is aimed at energy consumption in stormwater management and correlation with urban characteristics. To achieve it, Review of studies related to energy efficiency, in relation to stormwater management in municipal services was carried out. Further Identifying the factors that affect energy consumption for water pumping system, followed by assessment of factors and establishing relation between urban characteristics and energy consumption was carried out.

Urban factors at sub city level like vegetation, surface pattern, ground coverage vs open space etc. were identified and based on the research papers, published articles, their relationship was established. Various stakeholder consultation was done, discussions with officials about existing situation of stormwater was considered. Further 19 sites were selected within Ahmedabad municipal corporation boundary, based on the criteria’s like, waterlogging issues, building footprint data available, and presence of pumping stations. For these sites, further calculations were carried out for presence of urban factors. On the basis of these calculations and energy consumption in these areas, analysis was carried out, and it was analyzed that the overall energy consumption is not affected by just one factor, when all the urban factors come together into the planning, then as a whole energy consumption of that area is impacted. It was observed that ground coverage and surface runoff show directly proportional relationship with energy consumption, whereas vegetation, surface pattern (unpaved surface) shows inversely proportional relationship. In addition to this, cost calculations for conduit and non-conduit-based system was done and was observed that non-conduit based system consumed less cost, however for non-conventional system various factors like increase in response time, short term inconvenience due to water logging etc. comes along. Thus, it was concluded that future development should be done from the lens of urban factors, to minimize energy consumption. Also, if planned based on these factors a city can reduce the proportion of conduit-based systems and optimize presence of blue-green infrastructure, surface pattern and other urban factors identified, which would add on to reduction in energy consumption and cost involved. Also, these factors would help achieve sustainable development goals in long term like SDG 6, SDG 11, SDG 13, and SDG 15.

Climate change and its impact have become a critical issue, and greenhouse gas emissions are the most significant driver of this observed climate change. The net greenhouse gas (GHG) emissions have increased by around 43% in the last three decades, and the major contributor to this is the metropolitan cities. Therefore, the first step to reduce the GHG emissions is to identify the sources of these emissions in cities. According to India’s State Energy Efficiency Index 2019, out of the total electricity consumption in demand sectors, 38.5% of the energy is consumed by buildings, whereas the city municipal services consume only 3.6%. Even though the percentage contribution of the municipal services is less, the energy consumption is as high as 28 TWh (Terawatt hour) which amounts to around 8 x 108 tCO2e of emissions. So, there is a vital need to identify the sources of these emissions at the city municipal level. This research aims to investigate and assess the type and level of detail (LoD) of the data collected by different cities of India, which can be the potential indicators of the energy consumption and the greenhouse gas emissions of the city.

One of the significant gaps identified in the research carried out on GHG emissions of a city is that all the studies conducted so far have adopted a top-down approach by analysing the collective emissions from a city. This limits the opportunity to identify each source of emission, which is necessary to examine the impact of energy conservation measures proposed for individual sources. Therefore, a bottom-up approach is needed which will aggregate the GHG emissions from the individual sectors and sources to arrive at a city level emission data. The various initiatives like Swachh Bharat Mission and Smart City Mission under which the city municipality collects and reports the data were identified. The data parameters collected under each of these initiatives were analysed to arrive at a list of sources that could be probable indicators of the GHG emissions. A structure of the processes under energy and GHG emissions intensive municipal sectors was formulated. This study presents a generic framework of the parameters that can be used to calculate the GHG emissions for city municipal services, along with the guidelines for the municipalities to collect the data. This research will, therefore, help identify the feasibility potential of each city for determining the GHG emissions with respect to data available and the data which needs to be further collected. The findings of this research can be extended and implemented in the city missions and schemes as a set of parameters that needs to be gathered to estimate the GHG emissions of the city.

Around 69% of the urban population in India is concentrated in its Tier 1 cities. The city of Ahmedabad, currently the seventh-largest metropolis in India, has approximately 52 million m² of commercial space. By 2040, AUDA will have developed the proposed Central Business District (CBD). Envisioned as a high-density center in the city with a distinct character and urban form, the CBD has a proposed FSI of 5.4, almost three times the currently permitted FSI of 1.8, meaning a threefold increase in the built space. The Urban Heat Island Effect has been described as a critical environmental issue for dense urban areas and is of immediate concern, especially in a climate like that of Ahmedabad, where it is expected that the local average annual temperatures will increase due to urban heat islands. This will impact comfort conditions and the energy demand of the built environment, specifically the proposed CBD development. Urban building energy models for the CBD are developed for the baseline models 2020. Future scenarios as per IPCC climate change predictions are coupled with UHI to capture local urban weather across development scenarios of 2020, 2030, 2040, and 2050.

This paper is aimed at quantifying the UHI intensity and demonstrates the application of the Urban Weather Generator that estimates local hourly urban canopy air temperature and humidity profiles, and the morphed temperature output is used to study the effect of localized UHI on building energy use profiles. An increase of 37% is seen in the number of hours between 30°C - 40°C with and without UHI intensities dataset for 2020. Across the year 2020-2050 an increase of 2°C - 3°C increase in annual mean temperature is seen. Energy simulations are carried out in EnergyPlus using SimStock for datasets with and without UHI intensities to study the cooling EUI of commercial buildings. The initial results show that for every increase in 1°C rise in urban air temperature, the cooling energy consumption can increase by 25%-30%, and double FSI can increase the cooling energy consumption by up to 25%. The paper also presents a parametric study of high-performance building envelopes (ECBC) in an office building that shows an increase of 30% of the projected cooling energy consumption of commercial buildings in the CBD in 2050.

The average world temperature has risen by 0.91° Celsius in the last 100 years. This effect is more profound in metropolitan areas as compared to rural areas due to alterations in their natural fabric. Ahmedabad, located at 23.03°N 72.58°E, faces extreme summers with a temperature range of 46°C and 28°C. This paper presents a study that aims to assess the outdoor thermal comfort of the proposed Central Business District (CBD) area of Ahmedabad, India, and the impact of building densification on outdoor human comfort levels. The study area is about 1.28 sq km. The CBD area consists of 47% Commercial and 24% residential buildings out of a total of 0.31 million sq mt. of total floor space. The remaining 24% of the building are mixed-used, institutional, and health care. The study was carried out for the scenario for the years 2020, 2030, 2040, and 2050.

The study relied on morphed TMY files derived from the established methodology. The study limits itself to heat stress due to weather and building configurations, and it does not account for anthropogenic heat rejected from the building due to cooling systems. The Universal Thermal Climate Index (UTCI), which depicts the heat stress on humans produced by meteorological circumstances, was adopted to indicate thermal comfort and thermal stress. The building geometry data was collected from the CBD planning and regenerated in Rhino7.9. With the Dragonfly and Urban Weather Generator (UWG) tools, morphed weather files are generated for the simulations. Further, using these morphed weather (.epw) files, the ladybug (grasshopper plug-in) tool is used to compute UTCI. The study shows that outdoor thermal comfort was reduced from 2773(hrs.) to 2362(hrs.) under the 'no stress zone' in UTCI from the year 2020 to 2050. In the year 2050, the predicted floor area is increased by 15%. Hence for a decrease of 1% in comfort hours, there is an increase of 0.88% in the floor space area.

India has set its target of a 45% reduction in emission intensity by 2030. The building construction sector in India emits one-third of the total annual emission of CO₂. Rapid urbanization has spurred the demand for housing in India, this has resulted in an 11.1% rise in residential building construction over the last eight years. Current national policies focus on addressing energy efficiency during the operational phase of a building, which accounts for 60-70% of emissions in its entire lifespan. While upfront carbon constitutes 40% of emissions, this opportunity for reduction should not be ignored. This study is directed to embodied energy assessment of industrially produced walling technologies, that are identified as a substitute for conventional systems to meet the affordable housing demand in India. These technologies provide quick construction time and are economically affordable. Along with the available thermal heat transfer coefficient (U-Values), this database will be useful in the selection of walling technologies to address embodied and operational carbon emissions. The requirements for performing Life Cycle Assessment have been formalized in ISO 14044. However, the lack of availability of one comprehensive national dataset for all materials makes it necessary to adopt a robust framework that deals with sensitivity and uncertainty analysis. The study presents the methodology for conducting Life Cycle Analysis with an understanding of system boundaries, data quality requirements, consistency check, and interpretation of results. The functional unit considered is a square meter of a typical dwelling unit for 50 years. The results show industrialized walling systems have 35-58% higher embodied carbon than conventional walling assembly. This comparative database of external wall systems will help to make an informed decision regarding the selection of materials and systems to obtain 40-50% reductions in embodied carbon along with carbon offset plans for the building.

The worldwide market for split air conditioners is expected to grow at a remarkable annual growth rate (CAGR) of around 4.3%, reaching around $ 178 billion by 2026. Rising global temperatures combined with growth in population and rising disposable income make India and other Southeast Asian countries vulnerable to increased demand for air conditioning. In India BEE launched the star labelling of air conditioners in 2007 and the Indian seasonal energy efficiency ratio (ISEER) bands for star labelling are currently revised every 2 years. As room air conditioners (RAC) are the go-to mode of air-conditioning accessible to the common man, The study focuses on 135 typical split air conditioners in the CEPT University campus ranging from 1.5 TR to 2 TR. Six variables - indoor supply air temperature, return air temperature, supply airflow, filter condition, outdoor ambient temperature, ambient relative humidity, and condenser coil condition were checked for the air conditioners 5 times over a period of four months. Also, 1 unit was continuously logged 24x7 for supply air temperature, return air temperature, outdoor ambient air temperature, and relative humidity to generate a data set. The performance curves of the units were then generated in terms of cooling capacity and EIR/COP. The trends in cooling capacity and COP/EIR with respect to other variables and part load ratio were analysed and the gap in performance of the units with the manufacturer rated performance and expected performance as per the standard performance curve used in the Energyplus simulation engine was evaluated.

The use of air conditioning systems for comfort and space cooling is a major driving factor for the rising energy demand, accounting for nearly 10% of all the global electricity consumption today. The dependency on conventional vapour-based air conditioning systems has been increasing with time, resulting in rising energy demand for space cooling. The International Energy Agency (IEA) expects the energy consumption by air conditioners to be tripled by 2050. Direct evaporative cooling systems are an energy-efficient alternative to conventional air conditioning systems, particularly in hot and dry climates. The evaporative coolers offer a significant reduction in indoor air temperature while providing a desirable indoor air quality. However, maintaining indoor relative humidity levels in a comfortable range is a challenge with evaporative cooling systems.

This study aims to explore the potential for improving the comfort hours offered by the direct evaporative cooling system, operated through control algorithms. The input, control and performance parameters for the system were used to develop control algorithms, ranging from simple to advanced. The simple algorithms control system operation whereas the advanced algorithms control system and pump operation as well as modulate the parameters like fan airflow rate. The study follows a novel approach to using the experimental data to generate characteristic performance curves for the DEC system through experiments in a controlled environment, as opposed to assuming fixed saturation efficiency for simulations. The study also draws a comparison between the results obtained by energy simulations assuming default fixed saturation efficiency and with variable saturation efficiency using characteristic curves from the experiment. The experimental and simulation data are used to assess the comfort hours and energy savings achieved by the controlled system. The findings from the simulations imply that up to 44% energy savings can be achieved through control logic for direct evaporative cooling systems as compared to the baseline system. The hours within the comfortable range for temperature are increased up to 76% for a controlled system, indicating a rise of nearly 22% from the baseline. While the hours with both temperature and relative humidity in the comfort range were increased from 21% to 53%. Thus, the results suggest that direct evaporative cooling systems coupled with control algorithms have the potential to replace the conventional air conditioners, bringing about a change in the current energy scenario.

The fast-increasing levels of energy consumption have raised concerns over the excessive usage of resources and subsequent environmental impacts. India being a developing country, the power consumption has been increasing at a greater pace. The commercial building area accounts for 33% of the total built area, and it is increasing at a rate of 8-10% annually. Commercial buildings in India account for nearly 8% of the total electricity supplied by utilities. Electricity use in this sector has been growing at about 11-12% annually, which is much faster than the average electricity growth rate of about 5-6% in the economy. In such a condition, it is important to understand the pattern of energy consumption in commercial buildings and develop robust benchmarks. This would help designers and owners to set targets to choose appropriate technology, materials, products and retrofit measures for buildings and help users to operate the building efficiently. The statistical method for benchmarking requires a database of a large population of buildings in order to derive a robust benchmark. Due to difficulties in acquiring data for system level data for large population of buildings, there would be minimal information about buildings such as the annual energy consumption, floor area, regional weather conditions, number of occupants etc. Hence there would be low granularity of data in the database. The aim is to device a method to derive benchmarks for energy consumption in office buildings of India using both simulation and measured data. Through literature study from various sources, a database of input parameters for energy model, like built-up area, number of occupants etc. and Energy Performance Index (EPI) of 373 office buildings is gathered and analysed. Major source of data came from the ECO-III project, for which a standardized questionnaire was used to collect energy data of office buildings. From the analysis, range of the input parameters are derived and representative values for numerical input parameters like built up area, would be calculated using weighted mean. Appropriate assumptions would be made for the unknown input parameters, based on the literature review. A heuristic method of validation is carried out using batch simulations where the input parameters are discretized into levels and random combinations of these levels of each input parameters are made to carry out large number of simulation runs (300-500).

The initial coarse grid search uses the range of input parameters from literature study to derive 3 levels of input variables. The simulation output of EPI would be compared with the EPI from the literature for Goodness of Fit (GOF). The Normalised Mean Bias Error (NMBE) indice is used to check GOF. A margin of +/- 15 % NMBE is used to narrow down the search. From these narrowed down simulation runs, strong input parameter variables are identified by checking which variables repeat the most in the simulation runs that fit the NMBE threshold. A fine grid search which uses these strong input parameter variables would be carried out to identify the simulation runs with best Goodness of Fit (GOF). The same method of validation of simulation results is carried out for a number of buildings. These simulation runs would help identify end use consumptions and input parameters of best performing buildings, standard or average performing buildings and worst performing buildings which would help in developing benchmarks. These validated energy model could be used in different locations with weather data to simulate and develop benchmarks for different locations.

India is a developing country with an increase in population and energy consumption. Studies show that by 2050, the electric energy consumption from residential buildings is predicted to rise by more than eight times, it is necessary to develop energy-efficiency strategies focused on the residential sector to limit the escalating energy demand. In a country, which cooling- dominated, more than 60% of the energy is consumed for air conditioning through HVAC Systems. Though natural ventilation is an effective mode of cooling in buildings, not always. Thus, using Mixed-mode which is a combined use of natural ventilation and mechanical cooling systems could be a feasible solution to provide cooling and maintain thermal comfort. There is demand and scope for Mixed Mode controls in the Indian market. Most mixed systems are operated are and controlled on algorithms that are based on predefined static set-point temperature or based on occupancy schedule. While, the current researches and papers keep providing sophisticated algorithms that might not work in the long run, in real-time. Thus, this research tries to bridge this gap and focuses on the development of control algorithms that enable window operation, without sacrificing thermal comfort as well as minimizing energy consumption. The window opening algorithm is devised based on simple temperature or a combination of temperature and relative humidity control. The control algorithms are first simulated and analyzed for multiple parametric runs with differing climates, WWR, etc. Post analysis, a linear correlation is obtained for each condition. Later, this equation is coded and simulated again for a different set of parametric runs to check its feasibility. Developing this linear correlation by the system and getting better results is the self-learning ability of the algorithm, which the tried to be achieved by this research using DesignBuilder and EnergyPlus.

The algorithms are assessed primarily based on the annual comfortable hours. These are evaluated through the process of simulation. The initial analysis shows a linear correlation equation between temperature difference between outdoor and setpoint with outdoor temperature. The results based on this correction factor demonstrate that there is an increased comfort benefit with 16.2% lesser uncomfortable hours for the self-learning control algorithms compared to the basic reference in the Hot and Dry climate zones. The increase in comfortable hours for the considered parametric runs using self-learning algorithms varies from 0.2 to 16%. When comparing the performance of the algorithms in multiple parametric runs, it is found that climate-based parametric has potential benefits with corrected algorithms, while the percentage increase is found the least in Envelope typology. The simulations are again conducted for a different set of parametric runs different from the test set to validate the effectiveness of the algorithm. The validation runs exhibit the increase in no. of comfort hours with values ranging between 0.2 to 14.9%, showing the effectiveness of the. Overall, the comfort hours of the space through window operation are optimized. Thus, the outcome of this research is expected to enable better thermal comfort and effective control and operations in Mixed Mode buildings. Future research should refine the control algorithms for multi-zone building, multi-window operations and their functioning in real-world applications, and BMS.

24% of the total energy consumption is accounted for by the residential sector in India. This consumption is expected to rise by more than eight times by 2050. Looking at the growth in energy demand in the residential sector, there is a need for an understanding of energy use patterns in different households of the country. This energy demand is primarily driven by appliances and equipment. In addition to that, a better access to electricity also contributes towards the rise. However, with the limited availability of datasets, it is crucial to gather more data to understand this growth in energy use and its variations in the residential sector of the country.

This first of its kind, city specific comprehensive study is integrating the methodology and learnings from the Global Buildings Performance Network (GBPN) 2014 report on Residential Buildings in India: Energy Use projections and saving potentials, for an in-depth residential energy consumption analysis of apartment buildings in Lucknow city. Appliance details and electricity consumption data for different households are the key inputs in the study. The socio-economic factors are not considered. The data collection and analysis processes are referred from the GBPN 2014 report. The data analysis results in accurately benchmarking the residential buildings for effective energy management. The key metrics provides comparable baselines for similar buildings and helps in identifying key drivers of the energy use.

 The data findings could potentially influence the formulation of energy policy interventions customized, to reduce energy consumption. Having the knowledge of energy usage helps in implementing saving strategies. The comparable benchmarking dataset gathered through the analysis of annual electricity consumption provides information about the position of the building with respect to others. This promotes an understanding of future electricity demand in the city, thereby enabling better planning and a demand-side management program.

Interconnected factors, such as thermal comfort, indoor air quality, and energy performance, influence overall indoor environment quality. Finding a balance optimizes all three factors since improving one parameter can affect others. Buildings often use HVAC systems to maintain satisfactory indoor air quality and provide thermal comfort. However, they can significantly increase buildings' operational costs and energy consumption, accounting for 30% of India's primary energy consumption. The lack of comprehensive research that evaluates all three factors together in Indian office buildings motivates this study. This study aims to evaluate the thermal comfort, indoor air quality (IAQ), and energy performance of an office building in Ahmedabad, India, and understand the performance gap between the actual and expected values of these parameters.

The study proposes a novel indoor air quality and thermal comfort methodology that involves four stages: literature review, field data collection, analysis of the data, and recommendation for improvement. The field data collection includes a thermal comfort survey, sensor measurements of environmental parameters, and an evaluation of the building's energy performance. The methodology consists of carrying out a post-occupancy evaluation of the office building and comparing the findings with the ASHRAE 55 and ASHRAE 62.1 standards. The recorded data from the installed sensors and surveys of the employees in the office building will form the basis of the study. The collected data consist of indoor and outdoor air temperature, relative humidity, air velocity, globe temperature, CO2 levels, PM 2.5 and PM 10 levels, TVOCs, and HCHO.

 The assessment will analyze these parameters' correlation and how these parameters are affected by the existing HVAC system and compare it with the survey's subjective perception of the employees. The significance of this study lies in its ability to enhance the energy efficiency, indoor air quality, and thermal comfort of office buildings with respect to the standards.

The concern for environmental sustainability has led to a growing demand for reduced energy consumption and increased HVAC system performance. To evaluate the overall cooling efficiency of an HVAC system, a standardized and effective protocol needs to be developed. This can be achieved by deriving a metric framework from the performance evaluation of individual components, such as cooling capacity, EER, and COP. By combining these metrics into a standardized framework, the overall cooling performance of an HVAC system can be accurately evaluated. This evaluation is crucial for identifying areas of improvement and optimizing HVAC systems to achieve energy efficiency and cost savings. This study focuses on evaluating a demonstrative HVAC system in an NZEB building at CEPT University, Ahmedabad, which includes components such as a water tank with BPHE, air-cooled condenser, compressor, pump, and FCU. The efficiencies of individual components will be calculated to determine the overall cooling efficiency of the HVAC system.

India experiences high ambient temperatures in many regions, with temperatures reaching up to 48°C, which necessitates the use of mechanical cooling systems for indoor comfort. Air conditioners, are widely used for space cooling and account for 20%-40% of electricity consumption in India's residential sector. The ownership of air conditioners in India is projected to increase from 11% to 85% by 2050 (International electricity agency (IEA), 2022), and residential electricity consumption is expected to rise more than eight times under a business-as-usual scenario. However, appropriate control of indoor set-point temperature can yield significant energy savings and mitigate environmental impact.

This study investigates the impact of varying the setpoint temperature of split air conditioners on energy consumption for residential spaces in four Indian cities: Ahmedabad, Chennai, Delhi, and Bengaluru. The study is carried out in two stages. In stage 1, the energy consumption is determined through experimental evaluation using split air conditioners. The experiment is conducted at various setpoint temperatures in a low-energy cooling testing bed (LECTB) lab in Ahmedabad to determine energy consumption for 10-day profiles (Global Cooling Prize, 2018) that account for variability due to changes in outdoor temperature and humidity. The daily energy consumption for each city is estimated by binning cities days into 10-day profiles based on 24hr dry bulb temperature and relative humidity. In stage 2, simulation methodology is employed to estimate energy consumption at different setpoints.

The study concludes the percentage of energy savings achieved with each unit increase in cooling setpoint temperature for the cities of Ahmedabad, Chennai, Delhi, and Bengaluru by the employment of the two methodologies and differences in laboratory testing and simulation data. The study findings can aid in developing energy-saving strategies and determining the optimal temperature range for split air conditioners to achieve efficient cooling. Additionally, building owners and occupants can benefit from informed decisions regarding air conditioning usage to reduce energy consumption and minimize the environmental impact of air conditioning systems.

The current practice for calculating the U-value of an assembly relies on the Heat Transfer Equation (ΔQ= UAΔT), but it fails to account for the impact of thermal mass. Thermal mass plays a critical role in storing heat passing through an assembly, which is currently ignored in current practice. This study aims to address this issue by assessing the thermal mass of various walling technologies using guarded hot-box measurements. The thermos physical properties mentioned in building codes and standards such as BEE are only "typical values" that do not take into account the thermal mass of materials. Therefore, assessing thermal mass is crucial as it provides a more accurate database of the thermos physical properties of different construction materials and their real-world heat transfer scenarios. The objective of this study is to develop a numerical model that can accurately assess thermal mass. To achieve this, the research team will examine existing datasets and use them to create the model. The model will then be used to perform a reverse calculation that yields the desired result. Once the thermal mass assessment is complete, the thermal mass will be calculated using guarded hot-box measurements. This approach will provide a more comprehensive understanding of the heat transfer characteristics of various walling technologies and enable better-informed decisions in building design and construction.

The project involves testing three different insulating materials using a GHB setup and analysing the measured data. This analysis will be used to develop a numerical model that can calculate the thermal mass of each material - the amount of heat stored in it. The accuracy of the model will be verified using data obtained from the transient plane source method. Once validated, the same methodology will be used to assess the thermal mass of practical walling assemblies.

Building industry professionals have been spearheading the drive to curtail operational carbon emissions in buildings by deploying advanced building skins and optimized MEP systems. Nevertheless, the embodied carbon that arises from the extraction, production, transportation, repair, replacement, disassembly, and disposal of MEP equipment contributes significantly to the overall environmental impact of building products and systems. As such, it is imperative for building industry professionals to heighten their awareness of embodied carbon emissions to effectively mitigate their environmental impact.

The use of refrigerant has greater impact on the environment as they have higher GWP than carbon dioxide. Most MEP components are made of metals, which have a significant amount of embodied carbon. Additionally, large quantities of these components are frequently installed and replaced in buildings, resulting in a considerable carbon footprint. Despite the pressing need to evaluate the carbon emissions of HVAC systems, research indicates that this is not a commonly explored topic, with limited literature available on the subject. To bridge this gap in research, this study aimed to comprehensively evaluate the carbon emissions involved in the entire life cycle of an HVAC system. This was achieved using a simplified LCA method in tandem with CIBSE's TM65 model, which extensively quantified the various components of the HVAC system.

A meticulous and thorough assessment of every component of an HVAC system is imperative to accurately calculate embodied carbon emissions. However, due to the complexity of certain components, it was challenging to account for every detail. As a result, a certain level of uncertainty exists in the assessment. Nevertheless, the study was designed to minimize this uncertainty to a mere 5-6% of the total embodied carbon emissions, ensuring the highest level of accuracy possible. The study evaluated carbon emissions of two HVAC systems (new and old system installed for same spaces) in an office building in Ahmedabad, quantifying their components in detail to assess both embodied and operational carbon. Results were validated against existing literature. The study encountered limitations due to the absence of an Emission Database in India, which led to reliance on foreign EPDs and databases, as well as manufacturer details. However, the findings underscore the importance of developing an indigenous Emission Database to address this limitation. The study provides valuable insights into the environmental impact of HVAC systems and highlights the need to reduce embodied carbon emissions in the building industry.

There is a global paradigmatic shift in prioritizing reducing greenhouse gas emissions over reducing electricity consumption. This has led to the development of a net zero carbon approach towards projects. The scope of the study is about the contribution and impact of the building sector in terms of environmental impacts, with the focal point being the residential building sector, particularly for affordable housing. A Life Cycle Analysis was carried out for the study to understand the project's environmental impact broadly divided into the embodied and operational impacts. This impact has been quantified as kilograms of CO2 released into the atmosphere. ISO 14040/44 has been used as a reference for this assessment.

The case in consideration is an affordable housing design typology with two-sided open tower row housing from the multi-family group development category, proposed by the Bureau of Energy Efficiency under the Pradhan Mantri Awas Yojana 2022 scheme. The affordable housing sector in India faces an urgent need to provide housing for all; therefore, there is a crucial requirement to track the carbon emissions in this sector. The study is carried out for two construction materials: brick and mortar and EPS core technology (Expanded Polystyrene). The trade-off between embodied carbon, operational carbon, and thermal comfort in terms of unmet hours has been studied. It is found that EPS core technology has almost seven times higher embodied carbon than brick construction, whereas 11.32% lower operational carbon. The study also talks about the state of thermal comfort inside the spaces with the help of carrying out simulations. The discomfort, quantified by the amount of discomfort hours for EPS core technology, is 25.73% less than brick construction.

Personal Environmental Comfort Systems (PECS) offer an innovative solution to decentraliz space conditioning while providing individual control of thermal conditioning in a localized space. Despite several studies demonstrating the advantageous impacts of PECS on thermal comfort, a definitive conclusion regarding the efficacy of PECS in energy-saving potential has not been evaluated. This study aims to fill this gap by conducting a systematic review and meta-analysis of existing literature to identify the power requirements of PECS devices and their potential for energy savings compared to conventional systems. The study categorizes PECS devices based on the type of conditioning and heat transfer mechanism, and comprehensive power usage data is reported for each category. The study also identifies a performance metric and a framework for evaluating and reporting the energy efficiency metrics of PECS systems.

The study's findings reveal a wide variation in the power requirements and performance of PECS devices under different environmental and operational conditions. The study provides substantiated power consumption data for an array of PECS devices, making it easier to select the optimal technology that facilitates energy conservation and maximizes occupant comfort. The quantitative nature of the study enhances its applicability across a wide range of contexts, providing invaluable insights into the energy-saving potential of PECS. The study also highlights the need for further research and advancements to refine the design and operational viability of PECS technologies. The absence of universally accepted standardized methods for evaluating system performance is a significant limitation of existing research in this field. The proposed framework for evaluating and reporting the energy efficiency metrics of PECS systems would be instrumental in obtaining universal data that can be duly documented for widespread industrial application.

Standard heating, ventilation, and air-conditioning (HVAC) systems are designed to cool the entire building's volume. Regardless of how precisely regulated the thermal environment is, discomfort is still observed in the occupants' thermal comfort due to interpersonal thermal differences among occupants' thermal preferences depending on their clothing level, Activity type, and physiological responses to the environment. Standards have integrated the whole-body Comfort Model- Predicted Mean Vote (PMV) comfort model developed by Fanger (1970) derived from empirical data pertaining to the physics of Heat transfer and have limited significance in Non-homogenous environments as it may overestimate the heat production of the human body and misinterpret the energy demand. Therefore, this study emphasizes the need to investigate individual passive heat transfer mechanisms as an effect of physiological regulatory Controls. To achieve this, the Thermo- Regulatory Model JOS-3 has been used for the study to gain better insight into the perceptual response in terms of human heat exchange with comprehensive and non-homogenous environment boundary conditions impacting thermal comfort.

Cyclically changing predominantly indoor conditions are integrated into the Thermoregulatory Model JOS-3, wherein the physiological Model Differentiates 17 body segments into core and skin and mathematically regulates the active and passive mechanisms to reflect the thermal sensitivity of each body parts and the influence of local effects on whole body sensation. Literature studies show that Convective and radiative heat transfer contributes about 72% of the total heat transfer and Evaporative heat transfer contributes about 25%. The major physiological Factors impacting these mechanisms are Met Value, Skin temperature and Skin Wettedness. Hence, this study attempts to provide insights on the how the proportion of convective and radiative heat transfer (Sensible) and Latent Heat transfer varies in conjunction with the change in Skin temperature, Metabolic rate, and Skin wettedness with the change in the operative temperatures. Thus, the observations from the data collected will illustrate the effect of variation in Indoor Environmental conditions on the rate of Sensible (Convective and Radiative) and Latent heat transfer to the environment with the rate of heat production to understand Thermal Energy required by the human body . This report investigates the interplay between the human body's physiological processes, Passive heat Transfer mechanisms, thermal Comfort sensation and the corresponding Cooling load requirement. The findings of this investigation, Thermal Load analysis and thermal Comfort evaluations based on the human Thermo- physiological Model can provide invaluable insights into designing the Personal Environmental Control System, which will elucidate the disparity in energy consumption between a conventional HVAC system and personal cooling systems and optimizes individual thermal Satisfaction by neutralizing the impact of climate and buildings.

In recent years, the adaptive model of thermal comfort has gained traction as a more robust alternative to fixed set-point-driven design, which relies solely on predetermined indoor temperature settings. The adaptive model considers various factors that impact human comfort, such as humidity, air velocity, mean radiant temperature, and ambient temperature. Nonetheless, it is crucial to recognize the limitations of such models and the potential for discomfort and stress. This study examines a systematic approach based on simulations to assess the extent of heat stress with and without ventilation in residential buildings situated in Bhubaneshwar, India. The study analyses three building envelope materials, with two representing business-as-usual cases (RCC and Brick) and one representing a DHP housing project envelope (EPS Core technology). The selection of a multifamily affordable housing for the study is based on its inclusion in the ECO Niwas energy conservation initiative that promotes sustainable and affordable housing. Moreover, the standards for such housing are certified and replicable. The simulation employs the BEE standard model and utilizes a dynamic method of predicting heat stress using a simplified equation derived from regression analysis [Error! Reference source not found.], which is extrapolated for residential building calculations. The study analyses the limits of heat stress in a naturally ventilated residential unit using the India model for Adaptive Thermal Comfort Residential (IMAC-R) [Error! Reference source not found.] and ISO 7243 [Error! Reference source not found.] as a benchmark to define heat stress and understand the extent of deviation from comfort conditions. By employing such a comprehensive approach, we gain a deeper understanding of the impact of environmental factors on heat stress and develop more accurate strategies for mitigating its effects. The study offers valuable insights into the development of adaptive thermal comfort models, highlighting the importance of accounting for multiple factors in determining indoor thermal comfort. The results could aid in designing buildings that optimize thermal comfort while reducing the risks of heat stress and associated health issues. Ultimately, this study contributes to the field of thermal comfort by advancing our understanding of the complex relationship between environmental factors, human comfort, and stress. The dynamic approach for predicting heat stress, which utilizes a simplified equation to define heat stress, provides significant insights into the development of adaptive thermal comfort models. By simulating the indoor environmental parameters of the residence using Design Builder, this study found that the dynamic method accurately predicted heat stress in hot environments by calculating the Wet Bulb Globe Temperature (WBGT). The indoor WBGT varied between 16°C and 33°C, with an average of 28°C for RCC, 24°C for Brick, and 22°C for EPS Core Technology. The months of May and June recorded the worst heat stress, with RCC experiencing around 1200 hours, Brick around 800 hours, and EPS approximately 500 hours at higher metabolic rates. The study also found that when the indoor air velocity ranged from 0.9 m/s to 1.8 m/s, the indoor WBGT decreased by 0.15°C or 0.27°C throughout the year. Discomfort hours were approximately 5000 for RCC, 3600 for Brick, and 3200 for EPS Core Technology, with the highest discomfort observed during May and June when the outdoor dry bulb temperature (DBT) reached up to 40°C during the daytime. These findings underscore the importance of proper insulation and ventilation in maintaining a comfortable indoor environment and reducing the risks of heat stress and associated health issues. By understanding the thermal behavior of building materials and designing buildings to optimize thermal comfort, it is possible to create a safe and comfortable indoor environment for occupants.

In India, the rapid expansion of urban construction accompanied by an increase in global temperature changed the environment of urban regions. This is also impacting the thermal comfort of outdoor urban spaces and resulting in less accessibility to outdoor areas and health hazards. This study is conducted in the hot and dry city of Ahmedabad to assess the change in Outdoor thermal comfort of urban areas with the increasing floor area ratio of the existing urban setup. The site selected for study is the Central Business District (CBD), comprising 927 commercial and residential buildings with 1.3 km² area, with the opportunity of future development with 5.4 FSI from the current 1.8 FSI. However, this increase in FSI, in conjunction with climate change will impact the outdoor microclimate of this urban area. To carry out this study, a future weather file is generated for the year 2050 by considering the scenario of higher emissions of RCP 8.5, which predicted a 2° C temperature rise in 2050 compared to 2020. The increase in floor area is taken from the existing development plan for the CBD area and considering extreme development of 5.4 FSI by 2050.

The Universal Thermal Climate Index (UTCI), which depicts the heat stress on humans produced by meteorological circumstances, is adopted to measure thermal comfort. The Universal thermal climate index (UTCI) will give an equivalent temperature comprising the effects of various atmospheric factors like relative humidity, air temperature, wind speed, and radiant temperature in relation to the dynamic physiological response of the human body. The synergistic assessment of The Universal thermal comfort index (UTCI) of the CBD area with shifting FSI will help to understand the influence of urban geometry and densification on outdoor urban thermal comfort.

Conventional HVAC systems use a lot of energy to maintain a comfortable temperature throughout a building. This is inefficient because some occupants may prefer a warmer or cooler environment. PECS can improve comfort and potentially save energy by targeting only the occupied zones. This study investigates the relationship between PECS, thermal comfort, and energy efficiency in educational buildings. The research focuses on a case study of the LM College of Pharmacy (LMCP) building in Ahmedabad, India. Classrooms and offices were chosen as representative spaces. Different PECS options were analyzed using a spreadsheet tool to estimate energy consumption with and without PECS. The study found that PECS can significantly reduce energy consumption in classrooms (2% to 72%) and offices (1% to 50%) depending on the PECS type and ambient temperature. Conduction cooling, convective cooling, and convective heating PECS were the most effective in classrooms, achieving a range of 10% to 69% reduction in the Energy Performance Index (EPI). Ventilation PECS showed the most significant impact in offices, with a 4% to 52% EPI reduction. PECS can improve thermal comfort by providing personalized control and reducing energy consumption in educational buildings.

As India undergoes rapid urbanization, the prevalence of Urban Heat Islands (UHI) and air pollution pose significant challenges to urban liveability and environmental sustainability. Nature-based solutions (NBS) such as urban tree canopy cover have emerged as promising strategies to mitigate these issues. This research investigates the seasonal impact of native tree evapotranspiration rates on building latent cooling loads in Ahmedabad, India. Using a methodology that integrates literature review and 3-D tree modelling, the study evaluates the influence of ten native tree species on indoor latent loads. The Fast All-season Soil Strength (FASST) Vegetation Model is employed to calculate latent heat flux at the canopy layer, while empirical formulas from the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) Fundamentals guide indoor latent load calculations. The findings underscore the relationship between outdoor environmental parameters, tree characteristics, and indoor latent load variations. Notably, the study highlights that the evapotranspiration rates of single tree, influenced by factors such as density measured by Leaf Area Index (LAI), significantly impacts the outdoor moisture levels with seasonal variations.

While increasing urban vegetation density effectively mitigates the UHI effect, it may indirectly affect indoor humidity levels and potentially building energy consumption as well. Therefore, incorporating tree evapotranspiration rates into energy simulations and urban tree modelling are essential to balance the cooling benefits of tree with their impact on indoor environments while designing sustainable urban landscapes and create comfortable urban environments.

Decarbonization has become a global imperative, with India committing to reducing the Emissions Intensity of its GDP by 45% by 2030, compared to 2005 levels, according to the updated Nationally Determined Contributions (NDC). To achieve this goal, addressing carbon emissions, particularly embodied carbon and operational carbon, is crucial. Reports highlight the buildings and construction sector as the largest contributor to greenhouse gas emissions, accounting for a substantial 37% of global emissions. This sector's reliance on materials like cement, steel, and aluminum significantly contributes to its carbon footprint. However, India's current policy framework lacks specific regulations targeting emissions from this sector. Against this backdrop, this study aims to explore the correlation between the embodied carbon from concrete and reinforced steel with varying seismic zones. Specifically, it seeks to establish whether a relationship exists and analyze the coefficient/correlation if found. Focusing on the A1 to A4 life cycle stages, the study is conducted in Ahmedabad, utilizing data from the International Finance Corporation (IFC), Inventory of Carbon and Energy (ICE), and Environmental Product Declarations (EPD) relevant to the city. Life Cycle Assessment methodology is employed to calculate emission values for EPD, while for IFC and ICE datasets, emission factors are multiplied with the quantities of concrete and steel.

Initial analysis suggests a linear correlation between embodied carbon emissions from concrete and steel and the movement of building typologies across seismic zones 2 to 5. It's important to note that this study examines one iteration per seismic zone, with a larger dataset required to establish realistic coefficients. Once complete, this study will serve as the basis for introducing guiding benchmarks for embodied carbon emissions in buildings across each seismic zone.

The Indian Cooling Action Plan (ICAP),2019 has recognized refrigerant based cooling as an economic growth factor in the development of India. ICAP targets technological advancements in this sector through promoting passive cooling of the building, deployment of low GWP refrigerant and targeting demand side management of the cooling energy use through MEPs and star rating schemes. Currently an 68% share of refrigerant -based cooling is shared by the Split air conditioners. These modern split ACs boasts smart inverter technology that dramatically reduces energy consumption, but their efficiency often remains a mystery hidden within controlled lab tests. Therefore, this research is directed toward developing a testing protocol to assess the performance of split air conditioners in the real world, where setting up an elaborate lab-controlled environment is impractical and uneconomical. This shift promises valuable insights and will guide the consumers towards truly an energy-efficient air conditioner in the market and manufacturers towards a more holistic target to design.

The research lays out a step-by-step methodology for a standardized testing protocol in real- time conditions for any room split air conditioner (RACs). This experimental study is carried out based on different test procedures like the Indoor air enthalpy method mentioned in ASHRAE guidelines 116 and the cooling capacity test in IS 1391 part :2. This experimental study identifies optimal sensor configuration for measuring various parameters of the RACs like dry bulb temperature, wet bulb temperature, air velocity and power which is used in the assessment of the performance evaluation indicators like Coefficient of performance (COP) and Cooling capacity. It also specifies the minimum number of sensors on the indoor and outdoor unit, type of sensors, accuracy, precision, and location ensuring the total accuracy of the dataset is under 5%.

Many experimental research projects have been proposed before this study to assess the air conditioner performance under controlled testing conditions, whereas this research addresses the gap between the labs tested results with the real-world scenario through practical implementation of the testing strategy. For evaluating the performance of the air conditioner assessment is carried out through correlation and regression models whereas an uncertainty analysis helps in understanding the sensitivity of each parameter in the performance of the RACs. Hence this proposed protocol serves as a practical solution that is not only cost- effective but also provides an alternative solution to traditional lab testing, enabling broader access to reliable performance assessments for manufacturers and clients.

This research addresses the challenge of managing indoor air quality (IAQ) while minimizing energy consumption in building ventilation, focusing on developing a Ventilation Rate Prediction model for mixed-mode ventilation in Indian residential settings. The study conducts a comprehensive literature review on natural ventilation (NV), mechanical ventilation (MV), and their integration in mixed-mode ventilation, considering the ongoing debate between energy efficiency and IAQ control. The methodology involves creating a matrix of ventilation scenarios based on window configurations, mechanical fan setups, and temperature gradients. The study utilizes theoretical calculations and pilot experiments using the Tracer Decay Technique to explore the viability of hybrid ventilation in Indian homes. The findings highlight the importance of window size, fan speed, and temperature differentials in optimizing ventilation efficiency. Observations indicate that smaller window openings and deltas tend to align closely with theoretical estimates, showcasing an additive nature of natural and mechanical driving forces. Conversely, as window size or delta increases, the relationship transitions to a nonlinear and dynamic state, primarily influenced by buoyancy-driven forces.

Notably, a critical ventilation rate is identified, beyond which further increase becomes counterproductive, leading to rapid stabilization of indoor and outdoor conditions and subsequent reduction in ventilation rates. Overall, moderate window openings demonstrate reliability by providing a degree of control to natural driving forces, allowing mechanical forces to dictate resultant rates' fluctuations. In addressing limitations and future research avenues, it is imperative to acknowledge the study's focus on specific scenarios. The linear or additive relationships observed may vary with additional datasets, necessitating performing more experiments with a larger dataset. Furthermore, repeating experimental measurements multiple times and assessing the coefficient of variation are recommended to enhance result robustness. Conclusively, performing the outlined iterations promises more comprehensive insights, potentially leading to the development of empirical equations for calculating and predicting ventilation rates in concurrent mixed-mode ventilation setups.

The rapid urbanization due to the changing landscape of the country’s cities has fueled a boom in the residential sector, creating an unprecedented demand for housing units. The consequences of this urban juggernaut are undeniable. The burgeoning residential sector is poised to become one of the major consumer of energy which in turn unlocks a great opportunity for innovation of energy efficient constructions with low carbon footprint.The rapid influx into cities, already strained by overcrowding, will exacerbate the existing housing shortage. Addressing this growing demand through large-scale construction will significantly impact the carbon and energy footprint of the construction sector. In the pursuit of buildings with low carbon footprint, the judicious selection of building materials becomes paramount. India is actively promoting energy efficiency in the residential building sector through Eco Niwas Samhita( Part 1 and II). The state of building regulations today, reveals a crucial weakness: there are no strong embodied energy and embodied carbon criteria for different development levels. This disparity creates significant barriers to the construction industry's realization of sustainability, leading to excessive and wasteful material use that has an impact on energy consumption beyond operations. The lack of benchmarks makes it difficult to evaluate and monitor embodied energy and embodied carbon reduction efforts, which leaves a sizable blind hole in the comprehensive life-cycle energy evaluation of buildings. In the absence of embodied energy and embodied carbon norms, designers and builders could inadvertently favor well-known, resource-intensive materials like steel and concrete even when there are lower-embodied-energy substitutes. High-rise buildings can be less efficient due to increased built-up area (including additional circulation and servicable area ) compared to usable carpet area. High-rise development results in less efficiency of construction, as built-up areas increase in high-rise development, and habitable area may not, but the quantity of the material increases even when assessed per unit area of the space.Concrete and steel as materials used for construction constititute to be high contributors in the embodied energy and embodied carbon of the structural members.There is a huge gap in the availability of databse for India , thereby there’s a lot of uncertainity in any analysis that is done in regard to lifecycle assessment. A bigger gap exists in the environmental impact of transportation sector.

The building sector accounts for a substantial portion of energy consumption and energy- related emissions, with a global contribution of 30% and 26%, respectively (Buildings - Energy System - IEA, n.d.). Increasing construction, infrastructure development, and corresponding greenhouse gas (GHG) emissions have resulted in the rise in temperatures globally. In India, buildings contribute to 33% of the total electricity consumption. India's commercial building energy consumption is expected to rise from 59% in 2015 to 65% by 2040, with 700-900 sq. km (70%) of urban space yet to be built (Environmental Design Solutions, n.d.). India has pledged to increase the energy efficiency of its buildings in its commitments to the United Nations Framework Convention on Climate Change (UNFCC).

Modern buildings are energy intensive; thus, efficient building design, operation, and maintenance, exemplified by net zero energy buildings, is crucial for ensuring a sustainable, energy-efficient future (Rawal et al., 2019). Such buildings offer benefits on two fronts – achieving high energy efficiency and minimizing carbon emissions, bringing the transition to a decarbonized, trackable, and clean energy grid. This work intends to quantify the effectiveness of building energy efficiency measures and identify operational inefficiencies by learning from historical operational energy data at the building and sub-meter levels. The study was conducted on the Net Zero Energy Building (NZEB) at the CEPT University campus in Ahmedabad, as a use case and examined the feasibility of its active and passive systems. The high-resolution data (at sub-hourly intervals) obtained from the NZEB's building management system (BMS) was classified as two- dimensional time-series data. The work methodology was based on related literature reviews and aligned with standards ISO 50001, ISO 50002, and ASHRAE 228. The data was analyzed using widely accepted key performance indicators (KPIs) from standards such as IGBC, ASHRAE, USDOE, and NBI. This research sets out to find insights into the NZEB's performance, trends, and operational gaps, analysing Ahmedabad’s climate and NZEB’s end- use consumption, photovoltaic (PV) energy generation, and occupant thermal comfort. This project provides a template for further research on the NZEB at CEPT University for repeatable analysis of data generated in the future. A potential next step for this research that would remove redundancy is energy use prediction using artificial intelligence and machine learning, followed by verification from recorded data. Another study could focus on the standardization and repeatability of this exercise over various building types.

Indoor air quality has a significant impact on human health and comfort, and it is crucial to have proper ventilation and effective air filtration in residential settings. This study provides valuable insights for optimizing indoor air quality (IAQ) in residential environments by understanding how ventilation strategies through mechanical ventilation combined with recirculated air flow through a domestic standalone air purifier with different filter selection can influence clean air delivery rate (CADR). With this study, we can make recommendations for maximizing occupant well-being within homes. The findings are particularly relevant for individuals with respiratory sensitivities or living in areas with compromised outdoor air quality.The latest edition of ASHRAE standards, also known as standard 241 - "Control of Infectious Aerosols", introduces the concept of resilience to acceptable indoor air quality standards. The standard specifies the requirements for an equivalent clean airflow rate (CADR) in flow units per occupant in a space (ECAi). This clean airflow rate can be attained through outdoor air and air-filtered recirculated air. In the particular standard, there is a lack of guidance in terms of condition of the outdoor air with respect to pollutant concentration This allows for flexibility in compliance, using combinations of controls that optimize factors such as energy use, cost, ease of availability, and indoor air quality.

The study conducts a comprehensive literature review on Outdoor Pollutant concentration in terms of PM2.5 and PM10. The methodology involves creating a matrix of Clean Air Delivery rates (CADR) based on all possible Outdoor Pollutant levels, Minimum Ventilation rates, and safe levels of Indoor Pollutants. This is done by creating a mass balance equation taking all the above factors into consideration. Through experiments conducted in a low-energy cooling test bed that replicated the volume of a master bedroom, we investigated the impact of filter Minimum Efficiency Reporting Value (MERV) and ventilation configurations on clean air distribution rates within a residential setting. Using a standalone air purifier equipped with four interchangeable filters of varying MERV ratings (11, 13, 14, and 15), we maintained a constant mechanical supply ventilation rate of 42 cfm, conforming to the minimum recommended standard by ASHRAE 62.2, throughout the trials. The Air quality achievable naturally from outdoors were good and satisfactory levels. Ways of achieving other outdoor air quality levels have been explored experimentally in this research. Our findings showed that the CADR varied significantly based on the filter type. Higher MERV- rated filters demonstrated better air cleaning efficiency, with MERV 15 outperforming the others. While the fixed ventilation rate of 42 cfm met the minimum requirements set by ASHRAE 62.2, we observed 3 that increasing the ventilation rate under favourable conditions led to improved CADRs, especially when combined with higher MERV filters. The results emphasize the importance of selecting appropriate filters and optimizing ventilation rates. Homeowners and designers should consider different MERV ratings and placement strategies to enhance indoor air quality. In conclusion, this study provides valuable data on CADRs for various filter/ventilation combinations.

The whole building design comprises several elements and systems installed in a building, focusing on the energy consumption of a building including cooling, electricity, lighting, and equipment. Cooling energy is broadly divided into two parts, i.e., sensible and latent load. The two main components of energy consumption are sensible loads and latent loads. Extensive studies have been focused on the former topic, whereas, an ambiguity for latent load is observed. Substitution is considered for calculating latent load while assuming the energy consumption of a building. Latent load comprises 20% of building energy consumption With the current scenario of construction where the envelope is becoming tighter, an increase in differential pressure is observed. Parameters such as leakage area are taken into consideration through infiltration rate, which also compensates for fresh air inlet in a space. Other loads such as occupancy, and hygrothermal properties of the material also add to the total latent load in a building. Development of recent awareness about moisture transfer in a place, several studies have been conducted. Still, a fundamental understanding of moisture, its behaviour concerning outdoor conditions, an investigation to explore moisture, and its ancillary attributes is vague.

Currently, the load calculation for latent load is done on an assumption basis, where a constant value for infiltration is considered from the envelope; duct leakage and exhaust vents are still to be inculcated in the cooling/ heating load. The pressure gradient is neglected from the load calculations even though the change in pressure difference results in modification in air flow rate provided by the HVAC design system, hence a change in load modification. The topic covers the foundation of moisture and its specification, its behaviour in space, and its correlation to other parameters such as leakage areas and pressure gradients. Concluding the research to its applicability in HVAC systems and describing its overall impact on a macro scale i.e. building energy consumption.

In response to the severe heat wave of 2010, the Ahmedabad Municipal Corporation (AMC) developed the Heat Action Plan (HAP) in 2013. The findings indicate that the HAP effectively safeguarded public health by mitigating mortality linked to extreme heat. In the HAP, the citywide Cool Roof Program was also implemented, incorporating mandatory, voluntary, measures specifically focused on low-income housing (Ahmedabad Municipal Corporation 2016). This study investigates the effectiveness of cool roofs in mitigating UHI across varying built cover ratios in Ahmedabad's urban landscape. Using ENVI-met simulation software, three sites with different built cover ratios (20:80, 35:65, and 50:50) were analysed with varying Solar Reflectance Indices (SRIs). Results indicate that cool roofs can substantially reduce ambient temperatures, with the greatest reduction observed at a 50:50 built cover ratio and an SRI of 110, reaching 4.24°C during peak hours. Additionally, the study highlights the indirect impact on cooling energy demand, with reductions of up to 19.08% observed. These findings underscore the potential of cool roofs to mitigate UHI and optimize energy efficiency in urban environments, offering tailored strategies for sustainable urban development in Ahmedabad and beyond.

Rapid urbanization in India, driven by population growth and economic expansion, has intensified the Urban Heat Island (UHI) effect by reducing open spaces, vegetation, and water bodies. According to the National Disaster Management Authority of India (NDMA), heat- retaining materials, impervious surfaces, and anthropogenic emissions have increased urban temperatures by 2°C to 9°C compared to rural areas, leading to the classification of Heat Waves as a disaster. Cities generate heat from metabolic activities, equipment, and air conditioning, with dissipation primarily occurring at night, influenced by the Sky View Factor (SVF), which affects longwave radiation loss.

This study aims to understand the impact of Sky View Factor on Outdoor Thermal Comfort in terms of Heat Index (°C) and Universal Thermal Climate Index UTCI(°C) For the assessment of microclimate impacts, Ahmedabad is divided into 1 km grids based on night- time surface temperatures from MODIS (Aqua), with seven locations representing diverse urban morphologies. A transit route covers these spots within 1.5 hours, following WMO guidelines. Environmental parameters including air temperature (°C), relative humidity (%), wind speed (m/s), mean radiant temperature (MRT) (°C), and surface temperature (°C) were measured at specific times using a TSI 9565P (for temperature, humidity, and wind speed), EXTECH 200 (for MRT), and TG165 (for surface temperature). Measurements were carried out four times a day (morning, afternoon, evening, and night), twice a week, over a one-month period. SVF is determined using fisheye lens images captured on streets within a 100m radius of each site, analysed via a Python script. The results show that both high and low SVF values are associated with high levels of heat stress, and no linear correlation was observed between SVF and UTCI. The most balanced thermal comfort conditions were observed around an SVF of 0.56, where moderate thermal stress was highest (12.5%) and median Heat Index was significantly lower (~27°C), highlighting the importance of considering urban form, surface materials, and shading strategies in mitigating urban heat.

With the increasing advent of climate variabilities, Indian buildings rely more on mechanical ventilation and air conditioning to achieve healthier indoor spaces which is projected to increase fourfold by 2050. Concurrently, Indian cities face some of the highest air pollution levels, with an annual average Air Quality Index (AQI) of 147 categorize as ‘Unhealthy for sensitive groups’ under National Ambient Air Quality Standards (NAAQS). While thermally favourable outdoor conditions allow for mixed-mode building operation, undesired air quality prevents the buildings from taking advantage of such conditions. Due to the inevitable requirement for mechanical ventilation in such outdoor conditions, this study compares the energy consumption of conventional fresh air systems like the Dedicated Outdoor Air System (DOAS) and Personalized Ventilation (PV) across four Indian cities with diverse climate and air quality conditions.

The study employed a simulation-based approach, using a typical office building as the baseline model for analysis. Environmental parameters, including dry bulb temperature (DBT), relative humidity (RH), and air quality index (AQI), were evaluated across four cities to determine the optimal building operation mode. The analysis identified the hours when thermal conditions were suitable for natural ventilation but compromised by poor air quality, to calculate the energy use of mechanical ventilation to maintain acceptable indoor air quality. The power consumption of PV systems was derived from existing literature, considering various background temperatures within the adaptive thermal comfort range across the selected cities. The energy demand of PV systems ranged from 3 - 11 kW, depending on the system type. The results indicate that a ventilation airflow reduction of 5.5 l/s when using PV systems resulted in a 63% reduction in energy consumption. At a background temperature of 26 °C, PV systems achieved maximum energy savings of 72% in Chennai, followed by 70% in Ahmedabad, and 68% in Delhi. These findings highlight the potential of PV systems as an energy-efficient alternative for providing fresh air in polluted climates.

Urban Heat Island Effect (UHIE) in rapidly urbanizing cities has increased cooling energy demands, intensifying energy consumption. Trees help mitigate localized temperatures through shading and evapotranspiration (ET), which modifies microclimates by increasing ambient humidity. While shading directly lowers surface temperatures, ET’s impact on buildings’ latent cooling load remains underexplored. This study quantified tree ET's influence on cooling energy demand across Ahmedabad’s diverse urban morphologies. Varied spots with distinct land-use characteristics within a 1 sq.km. area were identified using remote sensing and microclimate analysis. Tree-specific parameters like seasonal Leaf Area Index (LAI) and canopy density were gathered through field surveys and literature reviews. ET rates were estimated using meteorological data and the Penman-Monteith equation, while microclimatic parameters like air temperature and relative humidity were analysed with ENVI-met simulations. The findings assessed trees’ role in cooling energy consumption and HVAC performance.

This study introduced a quantitative framework to assess the impact of tree ET on building cooling demand—an aspect often overlooked in urban microclimate research. A key contribution was the integration of field data, Penman-Monteith-based ET estimation, and ENVI-met microclimate simulations, offering a comprehensive method to evaluate the interaction between building energy performance and microclimate.

Results showed that tree evapotranspiration lowered microclimate air temperature but significantly raises relative humidity, increasing latent cooling loads. This impact varies with urban context, seasonal shifts, and time of day. Simulations across four representative meteorological conditions reveal the highest effect about a 2% rise in latent load, under peak DBT and nighttime scenarios. These findings underscore the need for context-specific analysis when integrating urban greenery into building energy models.

India has made progress in curbing its operational carbon emissions in buildings. The growing popularity of net-zero energy buildings focuses on operational carbon reduction. They do not necessarily ensure reductions in embodied carbon emissions. Accessibility to embodied carbon (EC)/embodied energy (EE) data for construction materials in India poses a major challenge due to its fragmented distribution across different peer reviewed and non-peer reviewed sources. The data is valuable to carry out lifecycle assessment (LCA) that allows one to quantify the environmental impact in the form of greenhouse gas emissions. The study aims to automate the process of collecting data from existing literature, extract values and validate the data using statistical means. This study aims to aid the national efforts like the upcoming revisions to the National Building Code (NBC), which is expected to include a dedicated section on EC, and the draft Energy Conservation and Sustainability Building Code (ECSBC) for commercial buildings, which includes templates for EC data disclosure. The study contributes by creating a framework for consolidating EC data into a structured repository along with establishing confidence levels for the collected data thereby fostering transparency for all the users. The data collection process began with the development of a structured query formation using Boolean operators and core keywords. Bibliometric analysis was integrated to refine queries, screen data, and enhance search query accuracy and relevance. A systematic review following the PRISMA 2020 guidelines helped to identify relevant peer-reviewed and non-peer-reviewed literature. The screening process employed an machine learning (ML) based classifier. Once the relevant sources were obtained, the EC value and any metadata concerning the temporal, regional, and brand/manufacturer specificity were mined using a larger language model (LLM) based tool. From the collected dataset, common materials like cement, steel, glass, brick which had relatively larger sample size underwent a statistical analysis. Amongst all materials, for EE brick has the largest sample size of 46 with an average EE of 2.37 MJ/kg and CI of 2.09-2.65. For EC the largest sample size was 11 for OPC with an average of 0.93 kgCO2e/kg with CI of 0.90-0.96 at 95% confidence level. The collected data is applicable for India specific practices and any practices which differ from the general trend may require values to be modified. Lastly, the study aims to set the foundation for a nationwide repository for Indian construction materials. The outcome of this research was a proof-of-concept framework that can evolve into an automated evolving repository.

India’s cooling demand is expected to rise significantly by 2050 due to urbanization, economic growth, and climate change. The India Cooling Action Plan (ICAP) projects an eightfold increase in cooling demand by 2037–38 compared to 2017–18 levels. However, conventional cooling strategies often fail to ensure optimal thermal comfort due to individual variations in thermal perception. Studies on thermal comfort models, such as the Predicted Mean Vote (PMV), show that even when indoor temperatures fall within the 80% acceptability range, only 58% of occupants feel comfortable. Personal Environmental Control Systems (PECS) offer a solution by providing localized cooling, enhancing comfort while reducing energy demand. However, most research examines temperature or humidity effects in isolation rather than their combined influence on human thermoregulation. Understanding how different body segments dissipate heat under varying environmental conditions is crucial for optimizing PECS design.

This study quantifies sensible and latent heat loss from 17 body segments under different operative temperature and relative humidity (RH%) conditions. Using the validated JOS-3 thermoregulation model, developed by Takahashi et al. (2021), simulations are conducted for operative temperatures between 15°C and 36.4°C and RH levels ranging from 30% to 70%, with constant air velocity and clothing insulation. The study systematically examines heat dissipation variations to identify thermally dominant body regions contributing most to discomfort. The research methodology aligns with prior studies by Kakitsuba et al. (1988) and Parsons (2014), ensuring simulation validation. Results indicate that heat loss patterns vary significantly with temperature and humidity. Sensible heat loss dominates at lower temperatures, while latent heat loss becomes critical at higher humidity levels due to evaporative cooling limitations. Key body regions, such as the head, hands, and feet, show the highest heat exchange rates, making them ideal targets for localized cooling. These findings align with studies by Havenith et al. (2007) and Arens et al. (2006), which highlight body segment-specific thermoregulation variations. By establishing a scientific basis for localized cooling strategies, this research supports the development of more efficient PECS solutions. Its findings have direct implications for enhancing thermal comfort while reducing reliance on energy-intensive centralized cooling systems. Future research could focus on experimental validation and real-time adaptive control integration to improve PECS efficiency in diverse climatic conditions.

The SDI is a competition among postgraduate and undergraduate students from Indian institutions to empower the next generation to combat Climate Change in the building sector. The competition invites to innovate for net-zero-energy, water, waste and climate-resilient buildings. SDI is a derivation of the Solar Decathlon competition originally conceived by the US Dept of Energy in 2002. In India, it is organized by the Indian Institute of Human Settlement (IIHS) and sponsored by Indo-US Science and Technology Forum (IUSSTF). Kill Bill 4.O achieved a cost-effective net-zero energy-water solution by integrating the various infrastructural needs of the project with centralized systems provided by the GIFT City while maintaining its individuality. Underground chutes are provided to connect to the central waste management facility along with centralized STP for sewage water treatment. The water demand is reduced at a building level via low flow fixtures and controllers, irrigational strategies and reuse of treated water to achieve a water autonomy of 45%. Monocrystalline solar photovoltaic panels have been integrated on the roof as well as on the South, West and East façades of the building due to the limited availability of land and caters to 100% building energy requirement. Our building façade has been developed as a minimalistic amalgamation of materials to emphasize the vertical garden wall which aims to provide visual comfort for the occupants and visitors alike while also acting as a buffer between indoor and outdoor environment. The North façade has the highest WWR to maximize the diffused daylight inside the workspaces. A UDI of 72% (inclusive of furniture) is achieved with effective window and shading strategies.The proposed Radiant cooling system reduces the HVAC energy consumption by 70% and achieves 100% comfort hours with the addition of IMAC mixed-mode operations and personal comfort systems.

A net zero energy, multi-family housing project is a relatively less explored area in the building industry. A net zero energy and water design are even more so. Team 0:0:0 from CEPT University upgraded the Savvy multifamily housing project located in Ahmedabad to triple zero design, that has net-zero energy and water, and has minimal waste thrown out from the system. The design process was developed with a data driven, integrated design approach by a multidisciplinary team from building science, architecture, and engineering disciplines along with the technical support of industry partners.

The project was envisaged by the Savvy group of Ahmedabad to fill an important housing gap in the local residential market - compact, affordable 1-bedroom units for the middle-income group.Energy and water use in residential buildings is driven to a large degree by building occupants. Data was gathered regarding the prospective building occupants for this project from multiple sources (e.g., Google search volume trends, publicly available demographic data and a bespoke survey especially designed for this project). The survey (240 respondents) gave us insights into potential conflicts between occupant’s expectations from their personal living environment and the goals of the project. For example, explicit provision has been made in our design proposal to give access to at least one open to sky terrace to all occupants which would have otherwise been used to install a larger PV array. This led to creating a user-oriented design where needs and interest of the occupants are given importance.Most of our interventions are multi-dimensional. For instance, performance evaluation against heat waves helps achieving goals for energy, resilience, and comfort. Prefab construction is an innovative intervention of mass-producing units in reduced time, with architectural and engineering inputs.

With careful considerations to principles of building science, affordability of users, market forces and user's desire to upgrade their lifestyle, a Renewable Energy Service Company (RESCO) model has been adopted for solar photovoltaic systems. The model has also been extended to making active cooling systems accessible to all occupants as a service, which, if purchased and operated individually, would be beyond the financial means of the occupants of the intended income group.

The outcome is a design that housed a total of 530 dwelling units with an EPI of 22.1kWh/m2-yr. The rooftop array helped attain net positive energy target by generating 23.1kWh/m2-yr of energy. Net water is attained by reducing water usage by efficient fixtures, rainwater harvesting and wastewater treatment. The waste generation is limited by reusing the waste for energy production. The resulting design achieved full FSI with an incremental cost of almost Rs. 3.2 crores and an annual operational savings of Rs. 10,560 for every apartment in terms of their electricity bills.

Sandhiya Jayakumar, M. Tech BEP alumni received Transloar Academy internship for the year 2020-21. Transsolar Academy is a one year program with six fellows from different parts of the world. The fellows for the year 2020-2021 were from Colombia, Cameroon, Honduras, Indonesia and India. The three months training includes 400 hours of training on sustainable design by the industry leaders, covering topics on climate responsive design, building physics and human comfort, passive design strategies, visual comfort, building systems and thermal comfort.

Ayushi Mishra, M. Tech student from Building Energy Performance program, secured the bronze award at a student competition organized by ASHRAE Region-at-Large (RAL) during Dec 2020 held at cape town (Hosted virtually). She represented ASHRAE’s Western India Chapter (WIC) at the event, which saw the participation of 16 students, representing 14 global chapters of the ASHRAE region. The topic of presentation was 'The Role of Occupant centric sensing and controls in HVAC'. The presentation explained the impact of Occupant behavior on HVAC energy consumption and the factors that influence it. It also discussed the existing codes and standards in that area and the ways to measure occupant behavior. Alternate cheaper and non-intrusive methods of behaviour measurement was one of the key areas of the discussion and an approach to incorporate the measured data into energy simulations was also discussed through cases studies.

To represent WIC at this platform, Ayushi cleared earlier rounds where she competed with nine contenders representing other reputed universities at the chapter level, where she had represented CEPT University. The competition aimed at in-depth understanding and presentation skills focused on heating, ventilating, air conditioning and refrigerating (HVAC&R) topics.

NetCarbon.IN, an integrated team of architects and engineers, worked together to create a 300,000 square foot, 15 story mixed-use building located in New York City. The challenge required the design of carbon-neutral building that would contain retail space, residential space, and a full-service restaurant. The project started off by climate analysis and design development inferences from the early design tools. Our aim was to enhance natural ventilation, increase exposure to natural light and sustainably source non-toxic material for the occupant's well-being in accordance with the WELL Standards.

The energy team calculated the number of hours wherein the building can operate in naturally ventilated mode, examined potential of radiant heating/cooling system, and worked upon strategy like capitalizing on constant ground temperature through geothermal heat pumps.Shoe box model was built and simulated as per the input parameters listed in ASHRAE 90.1 and ASHRAE 62.1 standards and results were analysed in the Design Builder and Energy Plus software.Inputs from daylight simulation and energy simulation were incorporated to achieve the final architectural design. To achieve the thermal comfort a geothermal heat pump system was coupled with Radiant cooling and was embedded in the floor. To cater to the latent loads and fresh air requirement Energy Recovery Ventilation and Dedicated Outdoor Air System were incorporated.

Priority was given to materials with low embodied carbon and materials that can improve Indoor Air Quality. The final EUI achieved was 82kWh/m2/yr. The renewable team calculated the energy that can be generated by BAPV and BIPV panels at roof and wall surfaces. In order to achieve the target of 4.07 KgCO2e/ft2 /yr. by the year 2030, three possibilities were explored i.e., on-site generation of electricity, on-site carbon sequestration, and demand-side management. For lower carbon emission, demand-side management was considered, by shifting the energy intensive activities such as water pumping, laundry, pre-cooling of office buildings to less carbon-intensive hours. This strategy also reduced the demand cost for the building hence reducing the overall energy cost and payback period. Innovative techniques like a)Algae wall panels for electricity generation and carbon sequestration and b)Piezoelectric tiles for electricity generation were considered.

Thus, final carbon emission achieved for the year 2020 is -0.53kgCO2e/ft2/yr. For the year 2030, the total amount of carbon emission is -0.19kgCO2e/ft2 /yr. and for the year 2050 it is -0.12kgCO2e/ft2/yr.

Kartikay Sharma, an alumnus of MTech BEP (2015-17) receives a four year fully-funded PhD position in Canada Excellence Research Chair in Smart, Sustainable and Resilient Communities and Cities, at Concordia University, Montreal. He will be working with Prof. Dr Ursula Eicker, Canada Excellence Research Chair, who specializes in energy efficiency in buildings and sustainable energy supply systems. At Concordia, she is leading a team of energy planners, designers, philosophers, biologists and building engineers to develop integrated strategies for efficient, creative, and accessible zero-carbon cities.

Jaydeep Bhadra, an alumnus of MTech BEP (2015-17) receives a four year fully-funded Ph.D. position in Energy Resilience and the Built Environment (ERBE), at the School of Architecture, Building, and Civil Engineering of Loughborough University. He will be working with Prof. Kevin J Lomas, Director, Loughborough, Centre for Doctoral Training in ERBE who specializes Dynamic Thermal Modeling of Buildings, Building Energy and Environment Research, Low-energy Building Consultancy, and Dr. ArashBeizaee, the Academic Manager of ERBE who specializes in Thermal Comfort and Indoor Environmental Quality, Building Performance Modelling and Monitoring, Low Energy Building Services Design, and Data Analytics for Building Energy Research.

He would pursue his Ph.D. in Comfort, Health, and Wellbeing with a major thrust on understanding how Personal Cooling System (PCS) can support the psychological adaptive mechanisms of the occupants of houses to remain comfortable during the household chores. His research will aim to assess the thermal comfort and energy savings potential of PCS devices in different conditions of a household.

The award is jointly funded by the UK Engineering and Physical Sciences Research Council (EPSRC) and Loughborough University.

The students of MTech Building Energy Performance at CEPT University wins Merit Award of ‘Architecture at Zero 2020’. ‘Architecture at Zero’ is a zero net energy design competition open to students and professionals worldwide. The 2020 edition was to create a zero net energy library for the San Benito County Free Library in Hollister, CA. The organizers received 230 entries from 49 countries. The competition was organized by Architecture Pacific Gas and Electric Company (PG&E) and the American Institute of Architects California (AIA CA). CEPT’s team shares Student Category Merit Award under with team from Cankaya Uni, Turkey, and Wroclaw University of Science and Technology, Poland.

CEPT’s team demonstrated a design solution integrating building envelop system with building services such as HVAC, lighting, and building controls. The solution optimized building envelop for its heat transfer and the integrated advanced HVAC and controls systems such as radiant cooling and active chilled beams for thermal comfort. The design solution provides 96% of daylight spaces and integrates Solar Photovoltaic having capabilities to generate approximately 350 MWh per year.

Saranya A, a Student of MTech BEP (2017-19) receives a four year funded PhD position at the Sustainable Buildings and Societies Laboratory (SBS Lab), at the University of Colorado Boulder, US. She will be studying under the guidance of Dr. Wangda Zuo, Associate Professor and Director of SBS Lab, who specializes in Advanced Modeling and Simulation for smart, sustainable, and resilient cities, building-to-grid integration, and Fast Fluid Dynamics (FFD). She would pursue her PhD in Architectural engineering, with a focus on the equation-based, object-oriented modeling approach using Modelica for Connected Cities and Communities.

Anmol Mathur, a student of MTech Building Energy Performance program has been awarded the BHAVAN Scholarship to research Urban Energy Modelling at Lawrence Berkeley National Laboratory (LBNL), USA. The Department of Science and Technology, Govt. of India and the Indo-US Science and Technology Forum (IUSSTF) have established a dynamic visitation program between Indian and US institutions and premier US Universities. The Building Energy Efficiency Higher & Advanced Network (BHAVAN) Fellowships and Internships are envisaged to create a sustainable and vibrant linkage between the two nations, as well as build long term Indo-American science and technology relationships.

Anmol Mathur, Shubham Solanki and Vardan Soi, 1styear students in the M. Tech Building Energy Performance program won the 1st place at Amravati Design Challenge - Small Scale Residential Development Scenariosorganised by Andhra Pradesh Capital Region Development Authority (APCRDA). The challenge was to develop a scheme of residential design for five different plot sizes, 4 orientation, and different family types, yet integrated with the principles of Amravati’s culture, vastu& most importantly climate responsiveness.

The designs were strategically developed to meet the IGBC Green homes criteria, attempting 60 points for platinum certification. These homes promise to provide 35% energy savings & 20% water use reduction as compared to a regular house & rigorously followed the ECBC. A predesign analysis suggested the optimal massing to reduce Solar insolation. The analysis showed equal heat gain from walls as with the roof due to the location being closer to the equator.

The envelope had a U-value of 0.7W/m2 & heavy thermal mass with stone cladding on the west & south-east facades. The Window wall ratio was derived through parallel heat flux & Spatial daylight autonomy simulations varying from 15% in the west to 40% in the North. The jail screens were designed in a way to maintain these WWRs & also provide shading cutting of 100% sun with radiations greater than 450W/m2.

Not just energy savings but also the comfort hours according to IMAC thermal comfort model the proposed design provides 30% greater comfort hours indoors.

A continuous shaded terrace with Integrated solar PVs as a pergola charged the house with renewable energy.

These strategies set a new benchmark for High-performance yet affordable houses.

Team Kill Bill from CEPT University, India, Team Kill Bill 3 upgrades the existing multifamily housing scenario in India, transforming it into a net-zero energy, low carbon and resource-efficient solution, catered specifically to the hot-and-humid climate zone prevalent in India. Developed with a data-driven integrated design approach by a multidisciplinary team and technical support of our Industry partners we present ‘Aatral Homes’ (Aatral is Energy in Tamil).

The proposal improved further an existing IGBC rated affordable housing project under the PMAY scheme, on a site based in Avadi – 20 miles from Chennai, Tamil Nadu, India.With careful consideration to the building science principles and affordability carrying out pre-design comfort & energy simulation we developed an optimized building massing having a huge potential for obtaining thermal comfort through natural ventilation. The design was able to reduce the Energy Use Intensity (EUI) by 50% from BAU scenario.

Team Kill Bill III (Left of Table) Krishna Patel, Siddarth Thoudam, Khushbu Bhatt, Niveditha Paulraj, C. H. Yesaswini, Suyashi Srivastava, Kaushik Jayaveeran, Shubham Solanki, Sreejith Jayaram, (Right of table) Vardan Soi, Nikhil Singh Yaduvanshi, Anmol Mathur, Gaurav Vakil, Krutika Sharma, Mahesh Kumar, Mayuri Agrawal, Akshat Gupta, Vismaya Paralkar

The business model of Rooftop solar leasing and Cooling as service were the highlights of the projects which ensured a Net-Positive energy design and providing central air conditioning to the homes using a higher efficiency and reduced capacity of the VRF Cooling system, at affordable prices.

Water efficiency measures coupled with wastewater recycling system reduces water demand by 50%. The design performance is tested for future weather scenarios up to 2025 using climate models.


The outcome was an entire urban design template of 24 such housing blocks on the 4 acres site to achieve 200% FSI. The solution ensures a 78% reduction in utility bills and 50% reduction in water demand from city supply, while keeping the final selling price well within affordability limits of Rs. 20-30 lacs, while keeping intact the developer's profit margin. Kill Bill 3-Report

Research Topic: HDR Imaging for an IOT based to lighting and blind controls using a desktop monitor mounted camera

University: Energy Studies in Buildings Laboratory, University of Oregon

Previous research showed that luminance data are much more valuable and reliable in predicting occupant demands and desires for visual environmental control of lighting and facade systems than the ceiling mounted illuminance sensors. Also measuring luminance at eye level is a better proxy for how we perceive light. High Dynamic Range Imaging (HDR) luminance sensors offer a higher spatial resolution signal than traditional illuminance-based photosensors to control overall lighting and façade systems. HDR techniques have been used primarily as diagnostic and predictive tools but have yet to be leveraged as a facade or lighting control signal.

This research examines the historic data set captured from the Firefly MV cameras to determine if the data from the top of the monitor correlate adequately with the Canon HDR data captured from the seated occupant’s perspective. This project also develops a low cost HDR sensor that can be easily positioned and oriented (or can be mounted on desktop) to capture the luminance data of the vertical visual field for lighting and façade controls. This research can help in developing a network of desktop monitor mounted cameras for HDR imaging and controls that can provide an Internet-Of-Things (IOT) based approach towards visual comfort.

Anmol Mathur, Shubham Solanki and Vardan Soi, 1st year students in the M. Tech Building Energy Performance program won the 1st place at the Stellar Façade Design Competition for their entry on designing a climate responsive and cost-effective façade design.

The competition was organized by Stellar Ventures (P) Ltd of the Stellar Group which has over 7 million sq. ft. in the National Capital Region of Delhi. The challenge was to provide a facade system for an 11-storied office tower in NOIDA with 4,40,000 square feet of built-up area. The façade system needed to be adaptive, responsive to human needs and climatic conditions, and minimize energy consumption for the building. The designs were judged by Ashok B. Lall, SuneetMohindru and AkshaySethi (Director, Stellar Group) and Akshay Garg (Head Architect, Stellar Group).

The CEPT team created an innovative and aesthetically appealing sustainable design solution that provides visual and thermal comfort, cuts direct sun and is cost effective. According to them, their design was “pleasing, vibrant and adds life to dull and monotonous all glass urban fabric of Delhi NCR”.

They started by analyzing and assessing loads with simulation software (Rhino-Grasshopper-Ladybug and Lightstanza) as well as manual calculations. They used solar angles, masks, radiation maps, as design tools and annual daylight levels, envelope and cooling loads to evaluate their design options. The result was an innovative tensile fabric fin system that was optimized for cooling load daylight and views. The jury found their “twist” appealing and also appreciated the durability and cost effectiveness considerations.

The design solution significantly reduced envelope loads by distributing windows appropriately on the facades, and the fin system cuts 70% direct solar radiation on the windows. They estimated a reduction of 40% for lighting energy and 20% for cooling energy.

CEPT’s Team KILL BILL won the 1st place trophy in the Urban Single Family Housing category of US Department of Energy’s “Race to Zero” Competition. Team Kill Bill was led by students in the M. Tech. Building Energy Performance program, with a goal to “kill” the electricity “bill” (shortage) in India. Fifteen CEPT students from the Faculties of Technology, Architecture and Planning made up the team. They replicated a real-life Integrated Design Process with specific roles for team members, seen internationally for high performance buildings but rare in India. Members of the Faculty of Technology mentored the team in an elective course.

Team Kill Bill, from left (back row) Vasudha Sunger, Arihant Jain, Nikhilesh Singh Bisht, Arjun Desai, Akash Ghadiyali, Sahil Priyadarshi Archanaa M, (front row) Kurva Dhonde, Pooja Mundhe, Vertika Srivastav, Aakanksha Khare, Mansi Parikh, Sandhiya Jayakumar, Shravya Reddy and (absent) Sumit Rawat

Over five months, they designed, prepared working drawings that included MEP systems, demonstrated performance with simulations, estimated costs and developed financing strategies. They designed a marketable house in Jaipur that is zero energy, zero water, gets WHO levels of air quality despite ambient pollution, and all this at a debt-to-income ratio that bankers found acceptable for their target market. Team KILL BILL’s work was commended by the jury for excelling under all categories of evaluation in the competition.

KILL BILL was one of the 39 participating teams, and the only team from outside the Americas that made to win the competition. They presented their design to a jury of industry leaders at the National Renewable Energy Laboratory in the USA.

Kill Bill 1-Report

Three students from CEPT University were selected for Ecosperity Young Leader’s Dialogue (EYLD) 2015 in Singapore on 18th & 19th September 2015 in Singapore, namely: Mohit Kapoor (Master of Urban & Regional Planning, MURP); Maaz Dixit (Master of Technology in Building Energy Performance, M. Tech); Kaushik Kumar (Master of Architecture, M. Arch). Ecosperity Young Leader’s Dialogue (EYLD) 2015 is organized by the National University of Singapore (NUS), School of Design & Environment (SDE) and Institute of Real Estate Studies (IRES). EYLD is a partner event of Ecosperity 2015 organized by Temasek Holdings. The objective of EYLD 2015 which is an annual forum that connects leaders of tomorrow with industry experts to dissect, discuss, and discover sustainable urban planning strategies. More than 140 students from 15 countries with various academic backgrounds such as urban planning, architecture, environmentalists, urban designers, etc. were selected for EYLD 2015.  Discussion Topics 1. Are developing countries equally responsible for sustainable development as developed countries? 2. Should sustainable urban planning prioritize society over the natural environment? 3. Moving forward, what are some sustainable urban planning strategies and technologies that should be explored further? Ecosperity is a series of sustainability-focused conferences presented by Singapore-based investment company Temasek in Singapore. The conference brings together CEOs, innovators, policy makers and thought leaders from around the world to explore the latest issues on sustainable growth. The name “Ecosperity” combines ecology with prosperity – embodying the belief that growth can take place in a sustainable manner. This year, the 2015 conference will focus on urbanization and the challenges and opportunities arising from developing smart and sustainable cities. https://www.youtube.com/watch?v=qXfuvbMltE4

The competition required students to focus on energy performance analysis and retrofit strategies for the Bundanon Art Museum and Bridge in New South Wales, Australia. The CEPT team’s solution proposed the following:

The team proposed a smart and energy-efficient design that would reduce uncomfortable hours by 94 per cent and reduce the need for active heating to only 27 hours per year, while also improving air quality.

Their retrofit strategy demonstrated a 54 per cent reduction in overall HVAC energy consumption through optimised system interventions.

A 303 kW roof top solar PV system was designed to generate three times the gallery’s annual energy needs, enabling year-round off-grid operation.

The students also achieved a 30.7 per cent embodied carbon reduction in the building façade through enhanced material choices, including the use of low-carbon materials, replacing insulation, improving cladding, and reducing steel.

This achievement reflects the students’ ability to respond to complex, performance-based design challenges with clarity, competence, and creativity.

The ASHRAE Building EQ Competition challenges students to assess the real-world performance of existing buildings through energy audits and benchmarking. This includes conducting a complete Level 1 energy audit of an existing building using the Building EQ platform. Teams benchmark building performance, explain the results, and propose well-justified energy conservation measures (ECMs).

The team conducted an ASHRAE Level 1 Energy Audit of a mixed-use office building at CEPT University, Ahmedabad, in line with ASHRAE Standard 211. They identified Energy Efficiency Measures (EEMs) to enhance building performance and reduce energy consumption. The audit involved benchmarking the building’s energy use, evaluating operational characteristics, and analyzing key performance metrics using the ASHRAE Building EQ methodology. They also proposed HVAC improvements, efficient lighting solutions, and cost-effective retrofits, focusing on comfort, sustainability, and practical strategies tailored to ASHRAE standards and the Indian building context for lasting energy savings.

The students competed against eight teams from various universities in and around Gujarat. The quiz rigorously tested their knowledge of HVAC principles, including psychrometry, refrigeration, and ventilation. This provided a valuable platform for the students to apply the theories they have studied, enhancing their academic and practical understanding of HVAC systems.  

The students from the MBEP program are continuing to excel in the Project StaSIO Annual Competition. During the 2024 edition of the ProjectStaSIO,  Siddhi Vashi (FT PG ’22) won in the 'Student Winner' category for her analysis of wall insulation and its impact on electricity consumption. 

The students from the MBEP program are continuing to excel in the Project StaSIO Annual Competition. Deepashree KS (FT PG ’23) earned the 'Honorable Mention - Clarity' award for her study on reducing building energy use through window shading and sun-control films in hot climates. 

Abhay Chavan, Fatema Khurshid, Mokshik Mehta, Reshmi Goswami, Shailender Kumar, and Vaishnavi Ambati (FT PG' 23) have been recognized as ‘Rising Stars’ in the 2024 Setty Family Foundation Net Zero Energy Design Competition, organized by the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE). Their team ‘Navika’ was mentored by Prof. Andre Sato from the School of Architecture and Urbanism, University of Sao Paulo along with Prof. Rajan Rawal & Minu Agarwal, CEPT University.