The study gave an overview of energy and its role in human life, starting from its spiritual conn... more The study gave an overview of energy and its role in human life, starting from its spiritual connotations to its physical manifestations and looking at the subject through the multiple views of philosophy, religion and science. It tried to define ‘energy efficient interior design’. Through simulation of hypothetical models, the study established that furniture elements play a significant role in influencing the air temperature within spaces.
ABSTRACT The present work is to understand the impact of setpoint temperature and coefficient of ... more ABSTRACT The present work is to understand the impact of setpoint temperature and coefficient of performance (COP) of a cooling system on cooling energy consumption, and its effect on thermal comfort of occupants in office spaces for the different climate zones of India. The occupants’ thermal comfort sensation is addressed here by the PMV (Predicted Mean Vote) index. The investigation of the mutual relationship between thermal comfort and energy demand is of the foremost importance to define the benchmarks for calibrating the energy use in office buildings. The first approach of this study is associated with the thermal comfort optimization and the second strategy includes energy consumption minimization while maintaining adequate thermal comfort. Results from the parametric energy simulation of a typical open plan office building are presented for different cases in order to evaluate the results with variations in cooling setpoint temperature and COP (an indicator of chiller performance). The results indicate there is a scope to reduce cooling energy consumption without compromising thermal comfort. India has a wide range of climatic conditions, hence this research comes up with a comparative analysis of cooling energy savings per unit increase in the cooling setpoint temperature for different climatic zones based on the system efficiency. Looking at the total energy use, this study suggests, the appropriate modulations in the setpoint temperature with respect to its climate zone.
ABSTRACT Buildings account for 30% of energy consumption in India, and it is estimated that 70% o... more ABSTRACT Buildings account for 30% of energy consumption in India, and it is estimated that 70% of the projected commercial building stock by 2030 is yet to be built. The recently established five-year US-India Centre for Building Energy Research and Development (CBERD) project aims to address the barriers for adopting low energy consuming strategies in buildings in India, while exploring the lessons that can also be applied to the US context. This paper evaluates the performance of two energy-conscious (EC) and two ‘business as usual’ (BAU) buildings in Ahmedabad, India using a combination of physical measurements, and a web-based occupant survey. The survey includes questions about Indoor Environmental Quality (IEQ): thermal comfort, indoor air quality, air movement and acoustics; it also asked questions about adaptive controls such as windows and fans. The EC buildings performed well in many categories compared to the ‘business as usual buildings’. One of the EC designed buildings in particular performed exceptionally well compared to the CBE database which consists of over 600 buildings mainly from the US but also from 9 other countries. In the other three buildings, dissatisfaction prevailed mainly with acoustic quality and office layout due to lack of speech privacy and visual privacy, but this is common across the larger database. More than 70% occupants were satisfied with thermal comfort in all except one of the BAU building and of the occupants who were uncomfortable mostly cited air movement being too low as the reason for discomfort.
Regulating clothing is one of the most obvious behavioural responses to changing thermal conditio... more Regulating clothing is one of the most obvious behavioural responses to changing thermal conditions. The extent of clothing, in turn, affects thermal sensation and acceptability. A lack of extensive thermal comfort field studies in India has meant that there has been very limited data on clothing related occupant behaviour in Indian offices until now. This paper aims to understand clothing norms and practices in Indian offices using data gathered via an extensive field study of thermal comfort in India. It uses the office occupants’ response to thermal sensation, acceptability and preference questions as experienced “right here, right now” from more than 6000 surveys together with simultaneous measurement of environmental conditions, clothing and metabolic activity. These surveys are administered in five climate zones across three seasons in air-conditioned, naturally ventilated and mixed mode buildings. The paper analyses clothing insulation as a behavioural response to changes in ...
Direct evaporative cooling (DEC) is one of the most commonly used cooling systems in many parts o... more Direct evaporative cooling (DEC) is one of the most commonly used cooling systems in many parts of the world with mainly hot and dry climatic conditions. Various simulation-based studies have been conducted to explore the potential of direct evaporative cooling in buildings. However, current dynamic thermal simulation tools use a simplified on/off control approach and do not allow modelling of situations where advanced algorithms are used in controlling DEC units. This paper couples EnergyPlus with Dymola® to simulate and assess the benefits of sophisticated control strategies for DEC units in mixed-mode buildings. This is a novel simulation approach for investigating control of DEC units in buildings that provides great flexibility for investigating future advanced control algorithms. The simulated results suggested that using the proposed sophisticated control algorithms for DEC units it is possible to achieve energy savings up to 35% compared to the base-case scenario and achieve...
This paper aims to identify the potential of natural ventilation for cooling a representative two... more This paper aims to identify the potential of natural ventilation for cooling a representative twobedroom residential apartment layout in India. India faces an unprecedented demand for residences and must reduce energy consumption associated with air-conditioning. Three significant climates and cities in India are investigated in this paper. The potential to extend the hours of the year for which thermal comfort is achievable using natural ventilation strategies is tested. This potential is identified by employing analytical methods to design and size ventilation capacity. Five natural ventilation design strategies are used over several scenarios varying window free area and ceiling fan speed. Indoor temperature setpoints are based on the India Model for Adaptive Comfort. Results are given as percentage of hours of the year for which natural ventilation is capable to remove calculated heat gains. Percentages of hours are divided into day-time and night-time. Findings show that the co...
This paper is based on the experiences of designing an energy efficient building in the warm-humi... more This paper is based on the experiences of designing an energy efficient building in the warm-humid climatic zone of India. The building is a part of a government project to promote awareness and use of energy efficient home appliances. From the stage of conception, therefore, it was designed as a demonstration project in order to integrate the knowledge dissemination objective with the performance of the building itself. This paper highlights the various challenges and opportunities that were part of the process of design, procurement (of building materials and components) and execution, towards making it an energy efficient building. It also presents in detail the thermal comfort analysis that was done to capture the adaptive model of thermal comfort for a mixed-mode strategy.
In the context of climate change, reduction in operational energy of buildings has gained a promi... more In the context of climate change, reduction in operational energy of buildings has gained a prominent focus amongst researchers and practitioners. India and the U.S. have both used design strategies to provide comfortable indoor environments with no or marginal reliance on conventional energy sources, but often with significant differences in their approaches and historical context. In particular, certain locations in both countries offer opportunities to design and operate buildings that are naturally ventilated or mixed-mode (combining operable windows and mechanical cooling). Historical or vernacular case studies have provided empirical evidence of climate responsiveness, however the lessons learned have not been deployed in the mainstream. Absence of rigorous performance evaluation might be one of the reasons behind the lack of large scale deployment of such design strategies. This paper documents the challenges and lessons learned from an extensive monitoring study undertaken i...
India has a largely cooling dominated climate where space cooling accounts for approximately 31% ... more India has a largely cooling dominated climate where space cooling accounts for approximately 31% of the energy consumed by commercial buildings. Deeper market penetration of air conditioning systems, higher income levels driving higher comfort expectations, and growing floor space have led to a steep rise in associated carbon emissions. India needs to adopt an energy efficient regime in which governments, businesses and individuals transform the way buildings are designed, built and operated, while still maintaining high levels of occupant satisfaction. Two diverse approaches are practiced in India to achieve energy efficiency. The first relies on passive design strategies based on traditional wisdom. The second relies on high-performance HVAC building conditioning systems. Most Indian climate zones offer opportunities to design and operate buildings as naturally ventilated or mixed-mode. But such design practices need to be promoted on the basis of scientific studies related to occ...
Abstract The ever-increasing demand for built spaces to cater to the needs of the tropical popula... more Abstract The ever-increasing demand for built spaces to cater to the needs of the tropical population compels for the adoption of sustainable building forms and passive design strategies. This research aims at studying the cases of six naturally ventilated occupied buildings constructed in the tropical ‘warm and humid’ climate of Pondicherry and Auroville, India. The buildings were subjected to long-term data logging and sporadic hand-held measurements. Indoor parameters of air temperature (Ta), surface temperature (Ts), and relative humidity (RH) across six living spaces, eight roof assemblies, and six passive design strategies were logged on an hourly basis and analysed for the hottest and coldest months. In order to estimate the thermal comfort, Ta readings of the most occupied zones were compared against ASHRAE-55 adaptive thermal comfort model and India Model for Adaptive Comfort (IMAC) temperature limits. This research showed that the hourly averaged Ta and RH in the six naturally ventilated spaces at the hottest summer hour (13:00) was between 31.0 and 33.2 °C and 56.0–69.0% while the outdoors were at 36.9 °C and 43.3% respectively. The hourly averaged rooftop and ceiling Ts for the unshaded roofs at 14:00 h during peak summer was between 53.0-43.4 °C and 36.6–31.0 °C respectively, while a shaded roof had a rooftop and ceiling Ts of 34.5 °C and 31.9 °C respectively. The passive design strategies of exposed cavity walls, night ventilation, and optimised building forms were found to be the most effective. The number of uncomfortable hours predicted by the ASHRAE model were found to be 93.4% higher than those by IMAC.
The study gave an overview of energy and its role in human life, starting from its spiritual conn... more The study gave an overview of energy and its role in human life, starting from its spiritual connotations to its physical manifestations and looking at the subject through the multiple views of philosophy, religion and science. It tried to define ‘energy efficient interior design’. Through simulation of hypothetical models, the study established that furniture elements play a significant role in influencing the air temperature within spaces.
ABSTRACT The present work is to understand the impact of setpoint temperature and coefficient of ... more ABSTRACT The present work is to understand the impact of setpoint temperature and coefficient of performance (COP) of a cooling system on cooling energy consumption, and its effect on thermal comfort of occupants in office spaces for the different climate zones of India. The occupants’ thermal comfort sensation is addressed here by the PMV (Predicted Mean Vote) index. The investigation of the mutual relationship between thermal comfort and energy demand is of the foremost importance to define the benchmarks for calibrating the energy use in office buildings. The first approach of this study is associated with the thermal comfort optimization and the second strategy includes energy consumption minimization while maintaining adequate thermal comfort. Results from the parametric energy simulation of a typical open plan office building are presented for different cases in order to evaluate the results with variations in cooling setpoint temperature and COP (an indicator of chiller performance). The results indicate there is a scope to reduce cooling energy consumption without compromising thermal comfort. India has a wide range of climatic conditions, hence this research comes up with a comparative analysis of cooling energy savings per unit increase in the cooling setpoint temperature for different climatic zones based on the system efficiency. Looking at the total energy use, this study suggests, the appropriate modulations in the setpoint temperature with respect to its climate zone.
ABSTRACT Buildings account for 30% of energy consumption in India, and it is estimated that 70% o... more ABSTRACT Buildings account for 30% of energy consumption in India, and it is estimated that 70% of the projected commercial building stock by 2030 is yet to be built. The recently established five-year US-India Centre for Building Energy Research and Development (CBERD) project aims to address the barriers for adopting low energy consuming strategies in buildings in India, while exploring the lessons that can also be applied to the US context. This paper evaluates the performance of two energy-conscious (EC) and two ‘business as usual’ (BAU) buildings in Ahmedabad, India using a combination of physical measurements, and a web-based occupant survey. The survey includes questions about Indoor Environmental Quality (IEQ): thermal comfort, indoor air quality, air movement and acoustics; it also asked questions about adaptive controls such as windows and fans. The EC buildings performed well in many categories compared to the ‘business as usual buildings’. One of the EC designed buildings in particular performed exceptionally well compared to the CBE database which consists of over 600 buildings mainly from the US but also from 9 other countries. In the other three buildings, dissatisfaction prevailed mainly with acoustic quality and office layout due to lack of speech privacy and visual privacy, but this is common across the larger database. More than 70% occupants were satisfied with thermal comfort in all except one of the BAU building and of the occupants who were uncomfortable mostly cited air movement being too low as the reason for discomfort.
Regulating clothing is one of the most obvious behavioural responses to changing thermal conditio... more Regulating clothing is one of the most obvious behavioural responses to changing thermal conditions. The extent of clothing, in turn, affects thermal sensation and acceptability. A lack of extensive thermal comfort field studies in India has meant that there has been very limited data on clothing related occupant behaviour in Indian offices until now. This paper aims to understand clothing norms and practices in Indian offices using data gathered via an extensive field study of thermal comfort in India. It uses the office occupants’ response to thermal sensation, acceptability and preference questions as experienced “right here, right now” from more than 6000 surveys together with simultaneous measurement of environmental conditions, clothing and metabolic activity. These surveys are administered in five climate zones across three seasons in air-conditioned, naturally ventilated and mixed mode buildings. The paper analyses clothing insulation as a behavioural response to changes in ...
Direct evaporative cooling (DEC) is one of the most commonly used cooling systems in many parts o... more Direct evaporative cooling (DEC) is one of the most commonly used cooling systems in many parts of the world with mainly hot and dry climatic conditions. Various simulation-based studies have been conducted to explore the potential of direct evaporative cooling in buildings. However, current dynamic thermal simulation tools use a simplified on/off control approach and do not allow modelling of situations where advanced algorithms are used in controlling DEC units. This paper couples EnergyPlus with Dymola® to simulate and assess the benefits of sophisticated control strategies for DEC units in mixed-mode buildings. This is a novel simulation approach for investigating control of DEC units in buildings that provides great flexibility for investigating future advanced control algorithms. The simulated results suggested that using the proposed sophisticated control algorithms for DEC units it is possible to achieve energy savings up to 35% compared to the base-case scenario and achieve...
This paper aims to identify the potential of natural ventilation for cooling a representative two... more This paper aims to identify the potential of natural ventilation for cooling a representative twobedroom residential apartment layout in India. India faces an unprecedented demand for residences and must reduce energy consumption associated with air-conditioning. Three significant climates and cities in India are investigated in this paper. The potential to extend the hours of the year for which thermal comfort is achievable using natural ventilation strategies is tested. This potential is identified by employing analytical methods to design and size ventilation capacity. Five natural ventilation design strategies are used over several scenarios varying window free area and ceiling fan speed. Indoor temperature setpoints are based on the India Model for Adaptive Comfort. Results are given as percentage of hours of the year for which natural ventilation is capable to remove calculated heat gains. Percentages of hours are divided into day-time and night-time. Findings show that the co...
This paper is based on the experiences of designing an energy efficient building in the warm-humi... more This paper is based on the experiences of designing an energy efficient building in the warm-humid climatic zone of India. The building is a part of a government project to promote awareness and use of energy efficient home appliances. From the stage of conception, therefore, it was designed as a demonstration project in order to integrate the knowledge dissemination objective with the performance of the building itself. This paper highlights the various challenges and opportunities that were part of the process of design, procurement (of building materials and components) and execution, towards making it an energy efficient building. It also presents in detail the thermal comfort analysis that was done to capture the adaptive model of thermal comfort for a mixed-mode strategy.
In the context of climate change, reduction in operational energy of buildings has gained a promi... more In the context of climate change, reduction in operational energy of buildings has gained a prominent focus amongst researchers and practitioners. India and the U.S. have both used design strategies to provide comfortable indoor environments with no or marginal reliance on conventional energy sources, but often with significant differences in their approaches and historical context. In particular, certain locations in both countries offer opportunities to design and operate buildings that are naturally ventilated or mixed-mode (combining operable windows and mechanical cooling). Historical or vernacular case studies have provided empirical evidence of climate responsiveness, however the lessons learned have not been deployed in the mainstream. Absence of rigorous performance evaluation might be one of the reasons behind the lack of large scale deployment of such design strategies. This paper documents the challenges and lessons learned from an extensive monitoring study undertaken i...
India has a largely cooling dominated climate where space cooling accounts for approximately 31% ... more India has a largely cooling dominated climate where space cooling accounts for approximately 31% of the energy consumed by commercial buildings. Deeper market penetration of air conditioning systems, higher income levels driving higher comfort expectations, and growing floor space have led to a steep rise in associated carbon emissions. India needs to adopt an energy efficient regime in which governments, businesses and individuals transform the way buildings are designed, built and operated, while still maintaining high levels of occupant satisfaction. Two diverse approaches are practiced in India to achieve energy efficiency. The first relies on passive design strategies based on traditional wisdom. The second relies on high-performance HVAC building conditioning systems. Most Indian climate zones offer opportunities to design and operate buildings as naturally ventilated or mixed-mode. But such design practices need to be promoted on the basis of scientific studies related to occ...
Abstract The ever-increasing demand for built spaces to cater to the needs of the tropical popula... more Abstract The ever-increasing demand for built spaces to cater to the needs of the tropical population compels for the adoption of sustainable building forms and passive design strategies. This research aims at studying the cases of six naturally ventilated occupied buildings constructed in the tropical ‘warm and humid’ climate of Pondicherry and Auroville, India. The buildings were subjected to long-term data logging and sporadic hand-held measurements. Indoor parameters of air temperature (Ta), surface temperature (Ts), and relative humidity (RH) across six living spaces, eight roof assemblies, and six passive design strategies were logged on an hourly basis and analysed for the hottest and coldest months. In order to estimate the thermal comfort, Ta readings of the most occupied zones were compared against ASHRAE-55 adaptive thermal comfort model and India Model for Adaptive Comfort (IMAC) temperature limits. This research showed that the hourly averaged Ta and RH in the six naturally ventilated spaces at the hottest summer hour (13:00) was between 31.0 and 33.2 °C and 56.0–69.0% while the outdoors were at 36.9 °C and 43.3% respectively. The hourly averaged rooftop and ceiling Ts for the unshaded roofs at 14:00 h during peak summer was between 53.0-43.4 °C and 36.6–31.0 °C respectively, while a shaded roof had a rooftop and ceiling Ts of 34.5 °C and 31.9 °C respectively. The passive design strategies of exposed cavity walls, night ventilation, and optimised building forms were found to be the most effective. The number of uncomfortable hours predicted by the ASHRAE model were found to be 93.4% higher than those by IMAC.
Uploads
Books by Sanyogita Manu
Papers by Sanyogita Manu