Vivian Loftness | Carnegie Mellon University (original) (raw)

Papers by Vivian Loftness

Proceedings of the 8th ACM International Conference on Systems for Energy-Efficient Buildings, Cities, and Transportation, 2021

Building management systems in commercial spaces commonly operate on predefined temperature setpo... more Building management systems in commercial spaces commonly operate on predefined temperature setpoints and control schedules. These systems typically do not consider the individual occupant's thermal preferences, which often leads to high thermal dissatisfaction rates, especially in shared spaces. Recent studies target human-in-the-loop personalized control, where each occupant's thermal preferences are taken into account. These control systems require occupants to frequently submit votes regarding their thermal comfort. Such votes are usually acquired using surveys with standardized scales. However, occupants often find these too cumbersome or literally do not understand the questions. This paper presents an intuitive thermal desirability scale to assess occupants' thermal comfort in scenarios with frequently queried feedback or control applications. The scale was tested in a survey with 100 participants against three common standardized thermal comfort scales. Results show that the thermal desirability scale provides a finer-grained understanding of control options for occupants than using a single standardized scale.

Adjunct Proceedings of the 2020 ACM International Joint Conference on Pervasive and Ubiquitous Computing and Proceedings of the 2020 ACM International Symposium on Wearable Computers, 2020

This annex describes specifications for the positioning of characters in text containing characte... more This annex describes specifications for the positioning of characters in text containing characters flowing from right to left, such as Arabic or Hebrew. Status This is a draft document which may be updated, replaced, or superseded by other documents at any time. Publication does not imply endorsement by the Unicode Consortium. This is not a stable document; it is inappropriate to cite this document as other than a work in progress. A Unicode Standard Annex (UAX) forms an integral part of the Unicode Standard, but is published online as a separate document. The Unicode Standard may require conformance to normative content in a Unicode Standard Annex, if so specified in the Conformance chapter of that version of the Unicode Standard. The version number of a UAX document corresponds to the version of the Unicode Standard of which it forms a part. Please submit corrigenda and other comments with the online reporting form [Feedback]. Related information that is useful in understanding this annex is found in Unicode Standard Annex #41, "Common References for Unicode Standard Annexes." For the latest version of the Unicode Standard, see [Unicode]. For a list of current Unicode Technical Reports, see [Reports]. For more information about versions of the Unicode Standard, see [Versions]. For any errata which may apply to this annex, see [Errata].

Increasing the pervasiveness of vegetated surfaces in urban areas has significant value for the a... more Increasing the pervasiveness of vegetated surfaces in urban areas has significant value for the aesthetic and environmental improvement of our cities. Roadways, parking lots, and building roofs offer the most significant untapped areas for urban landscaping. This report will ...

The design-performance space denotes a virtual space that can be constructed based on discretized... more The design-performance space denotes a virtual space that can be constructed based on discretized design variables and performance indicators. For an n-dimensional design-performance space, n = d + p,whereby d = the number of discrete design variables, and p = the number of discrete performance indicators. Once constructed, this space can be visualized and used by the designer to explore the relationship between design variables and corresponding performance attributes. We present, for the building design domain, an approach to generation and exploration of the design-performance space. In this approach, an initial design is used to generate a set of alternative designs that collectively constitutethe design space. One way of doing this relies on the "scalarization" of design variables. The scalarization leads to the representation of a building as a point in a d-dimensional design space. Each coordinate ofsuch a space accommodates a salient (semantic or geometric) design ...

This paper proposes a method comprising procedures to calibrate an EnergyPlus whole building ener... more This paper proposes a method comprising procedures to calibrate an EnergyPlus whole building energy model. An occupant behavior data mining procedure is developed and tested in an office building. Workday occupancy schedules are generated by mining the office appliance energy consumption data. Hourly and monthly power, energy, and temperature data are collected and used for lighting, equipment and HVAC systems energy performance calibration. The result shows a 1.27% mean bias error for the total annual energy use intensity. The proposed calibration method provides a scientific and systematic framework to conduct high accuracy EnergyPlus model calibration.

An International Perspective on the Office of the Future. A Framework for Designing and Managing ... more An International Perspective on the Office of the Future. A Framework for Designing and Managing the Office of the Future. A Process for the Field Evaluation of Advanced Office Environments. Japan's Rapid Approach to the Office of the Future. Toshiba Headquarters. NTT Twins Regional Headquarters. ARK Mori Building. Umeda Center Building. Glimpses of Invention. Major Design Changes for the Office of the Future. Appendices.

IOP Conference Series: Earth and Environmental Science, 2019

Earthen building materials offer an environmentally sustainable alternative to conventional mater... more Earthen building materials offer an environmentally sustainable alternative to conventional materials because they are locally available, minimally processed, and waste-free. However, they have not been comprehensively implemented because their technical data is highly variable, and they are not fully represented in building codes. To address these hurdles, this paper presents an environmental assessment and a policy repair review, including an environmental embodied impact analysis, and a discussion of the regulatory development required for earthen construction. The results of the environmental assessment show that earthen wall assemblies significantly reduce environmental impacts by 62-99% when compared with conventional assemblies such as timber frame and concrete blocks. Additionally, the policy discussion provides recommendations to overcoming materials variability and regulatory organizational collaboration. Overall, this paper highlights the importance of environmental and p...

Healthy, Intelligent and Resilient Buildings and Urban Environments, 2018

A change-point (piecewise linear regression) model fitted to the pre-retrofit data as the counter... more A change-point (piecewise linear regression) model fitted to the pre-retrofit data as the counterfactual for the savings calculation, is considered to be the best approach to evaluating the energy savings of building retrofits (ASHRAE Guideline 14). However, when applied to a large portfolio savings analysis with substantial multi-year data, the change-point model does not fit the data well in some cases. The study thus aims to improve the accuracy of the changepoint model by: 1) using more advanced non-linear models, 2) incorporating additional input features, and 3) increasing the time resolution of input variables. We found that random forest regression (RF) models with an array of climate (humidity, wind, solar radiation, etc.), time (day of the week, season, holiday), and energy consumption of the immediate past 1-4 hours (energy lag terms) outperformed the change-point model, shallow neural networks, and support vector machine regression (SVR). Our result implies that high resolution smart meter data should be used in place of monthly utility bills to more accurately evaluate retrofit savings. We further explored the relative contribution of the input variables to the random forest regression model using Shapley Value, a game theoretic variable importance metric. We found that the most important input feature is the energy consumption of the immediate past (or energy lag terms). We also found that solar radiation and weekend day indicators are more important than outdoor temperature. The improved model could provide better insights to portfolio managers in planning future energy retrofits. Policy makers could also use such models to evaluate the average energy saving potential for energy policy changes, such as the requirement of minimum insulation level, and lighting equipment efficiency.

Springer eBooks, Oct 26, 2006

On average, Americans spend 90% of their time indoors, and it is estimated that indoor pollutant ... more On average, Americans spend 90% of their time indoors, and it is estimated that indoor pollutant levels can be two to five times higher than outdoor levels. Rosenkranz Hall incorporates environmental controls, such as local task lighting, bi-level light switching, and access to thermostats to allow occupants to adjust visual and thermal conditions to their preferences. Materials and finishes with low Volatile Organic Compound (voc) content were chosen to reduce exposure to unhealthy air particulates, maintain excellent air quality, and preserve occupant health. Wood materials do not contain any added urea-formaldehyde, and paints and carpets were selected to have low voc content.

Environmental Health Perspectives, Jun 1, 2007

Journal of the Acoustical Society of America, May 1, 2002

Lack of speech privacy has been reported to be the main dissatisfaction among occupants in open w... more Lack of speech privacy has been reported to be the main dissatisfaction among occupants in open workplaces, according to workplace surveys. Two speech privacy measurements, Articulation Index (AI), standardized by the American National Standards Institute in 1969, and Speech Privacy Noise Isolation Class (NIC′, Noise Isolation Class Prime), adapted from Noise Isolation Class (NIC) by U. S. General Services Administration (GSA) in 1979, have been claimed as objective tools to measure speech privacy in open offices. To evaluate which of them, normal privacy for AI or satisfied privacy for NIC′, is a better tool in terms of speech privacy in a dynamic open office environment, measurements were taken in the field. AIs and NIC’s in the different partition heights and workplace configurations have been measured following ASTM E1130 (Standard Test Method for Objective Measurement of Speech Privacy in Open Offices Using Articulation Index) and GSA test PBS-C.1 (Method for the Direct Measurement of Speech-Privacy Potential (SPP) Based on Subjective Judgments) and PBS-C.2 (Public Building Service Standard Method of Test Method for the Sufficient Verification of Speech-Privacy Potential (SPP) Based on Objective Measurements Including Methods for the Rating of Functional Interzone Attenuation and NC-Background), respectively.

Springer eBooks, 2013

Diminishing natural resources, increasing levels of carbon emissions from the transformation of r... more Diminishing natural resources, increasing levels of carbon emissions from the transformation of raw materials into products, and the growing demand for consumable materials are factors that raise the question "how can a balance between the need for development and the protection of natural resources be created"? As a large share of the energy consumption is related to buildings, analysing the role of advanced materials in architecture and its contribution to sustainability is essential. This paper discusses nanotechnology's promise of lower energy and raw material consumption, reduced waste, greater safety and a healthier environment in the context of sustainable architecture. Nanotechnology is an expanding and innovating area of research and in architecture, it will greatly impact construction materials since the fundamental properties of materials like surface-to-mass ratio, elasticity, conductivity and strength can be controlled at nanoscale. Products like high-insulating panels, self-cleaning and heat-absorbing windows will influence the building industry as such materials have the potential to improve the energy efficiency, durability, economy and sustainability of the built environment. Nano insulating coatings are more efficient than traditional insulators and have a lesser environmental impact. As they can be used for the renovation of existing buildings, they increase the potential of reuse without the aesthetic and functional compromises often required by thick layers of insulation. This paper investigates the application areas of nanomaterials in the construction industry, illustrated with case studies. Investigating the opportunities and challenges provides the basis for the successful implementation and development of these materials.

Springer eBooks, 2013

series (ESST) addresses the grand challenge for science and engineering today. It provides unprec... more series (ESST) addresses the grand challenge for science and engineering today. It provides unprecedented, peer-reviewed coverage in more than 600 separate articles comprising 20 topical volumes, incorporating many updates from the first edition as well as new articles. ESST establishes a foundation for the many sustainability and policy evaluations being performed in institutions worldwide. An indispensable resource for scientists and engineers in developing new technologies and for applying existing technologies to sustainability, the Encyclopedia of Sustainability Science and Technology series is presented at the university and professional level needed for scientists, engineers, and their students to support real progress in sustainability science and technology. Although the emphasis is on science and technology rather than policy, the Encyclopedia of Sustainability Science and Technology series is also a comprehensive and authoritative resource for policy makers who want to understand the scope of research and development and how these bottom-up innovations map on to the sustainability challenge.

Energy for Sustainable Development, Aug 1, 2016

Energy consumption in Indian building sector is increasing at high rate. The National Building Co... more Energy consumption in Indian building sector is increasing at high rate. The National Building Code of India specifies a narrow comfort temperature range between 21 ºC and 26 ºC for all types of buildings and for all seasons. A thermal comfort field study was conducted in 32 naturally ventilated buildings, collecting a total of 2610 samples spread over a total period of four years, covering multiple seasons, age groups, clothing types and building types. Questionnaires were administered to building occupants to record sensations and preferences for air temperature, relative humidity and air velocity on ASHRAE seven point and five point scales. The objective of the study was to evaluate thermal comfort of occupants and study the methods of thermal adaptation such as adjusting clothing, window opening, and use of air circulation fans. Griffith's method was used to determine thermal neutrality. The comfort temperature for summer and winter season was found to be 30.6 ºC and 25.2 ºC, respectively. Preferred clothing level for summer was found to be 0.30 clo, whereas in winter it was 0.80 clo. Preferred air velocity was observed as 0.62 m/s in summer season and 0.27 m/s in winter. Controlling air velocity has been found to be preferred method of thermal adaptation over adjusting clothing and window opening.

Building and Environment, Nov 1, 2016

Thermal comfort standards such as ASHRAE 55-2013 defines comfort boundaries which are based on th... more Thermal comfort standards such as ASHRAE 55-2013 defines comfort boundaries which are based on the experimental results conducted in climatic chambers and field studies. The current comfort standards do not reflect the cultural and climatic diversity of India. A thermal comfort field study was conducted in 32 naturally ventilated buildings, collecting a total of 2610 samples spread over a total period of four years, covering all seasons, wide age groups, clothing types, and building types. In the present study, ASHRAE comfort boundaries at three different air speeds-still air (up to 0.2 m/s), natural air flow (0.2 m/s-0.5 m/s) and forced air flow with ceiling fan assist (0.5 m/s-1.5 m/s) are investigated. The method of calculation suggested by the ASHRAE 55-2013 and ISO-7730 were followed to determine extended acceptable temperature ranges for comfort at elevated air speed. Comfort boundaries are defined based on climate specific adaptations, the role of air speed and thermal preferences. Results from this study indicate that subjects in naturally ventilated buildings of this region are comfortable at temperatures different from those suggested by ASHRAE 55 and ISO-7730 standards. New extended boundaries of comfort zones are proposed considering various adaptations specific to this region, including the role of air speed to offset the temperature. The proposed comfort zones show that subjects are comfortable up to 32˚C at still air condition (0 m/s-0.2 m/s) and up to 35˚C at higher speed (up to 1.5 m/s) in naturally ventilated buildings in the composite climate of India.

Architecture on the 16th of May 1975, in partial fulfillment of the requirements for the degree o... more Architecture on the 16th of May 1975, in partial fulfillment of the requirements for the degree of Master of Architecture. Architecture must be conciously and precisely designed to integrate the life of its occupants with the cycles of nature. This thesis is a collection of information on the natural microclimate which exists on the untouched land, and that which could predominate by intervention and design. An understancing of site potentials and limitations involves: first the survey of local climate elements, second the evaluation of each climatic impact in physiological terms, and third the development of a design response for each microclimate condition. Field reconnaissance gives an invaluable overall picture to the designer, enabling him to design with respect for the site. What is proposed here is a method, an index, for reestablishing in bui/t form, a more delicate exchange between man and nature. The information is organized and presented in such a way that the thesis may be used as a handbook by the architect, engineer, contractor, or homeowner who is interested in making more sympathetic and creative use of a building site.

Proceedings of the 8th ACM International Conference on Systems for Energy-Efficient Buildings, Cities, and Transportation, 2021

Building management systems in commercial spaces commonly operate on predefined temperature setpo... more Building management systems in commercial spaces commonly operate on predefined temperature setpoints and control schedules. These systems typically do not consider the individual occupant's thermal preferences, which often leads to high thermal dissatisfaction rates, especially in shared spaces. Recent studies target human-in-the-loop personalized control, where each occupant's thermal preferences are taken into account. These control systems require occupants to frequently submit votes regarding their thermal comfort. Such votes are usually acquired using surveys with standardized scales. However, occupants often find these too cumbersome or literally do not understand the questions. This paper presents an intuitive thermal desirability scale to assess occupants' thermal comfort in scenarios with frequently queried feedback or control applications. The scale was tested in a survey with 100 participants against three common standardized thermal comfort scales. Results show that the thermal desirability scale provides a finer-grained understanding of control options for occupants than using a single standardized scale.

Adjunct Proceedings of the 2020 ACM International Joint Conference on Pervasive and Ubiquitous Computing and Proceedings of the 2020 ACM International Symposium on Wearable Computers, 2020

This annex describes specifications for the positioning of characters in text containing characte... more This annex describes specifications for the positioning of characters in text containing characters flowing from right to left, such as Arabic or Hebrew. Status This is a draft document which may be updated, replaced, or superseded by other documents at any time. Publication does not imply endorsement by the Unicode Consortium. This is not a stable document; it is inappropriate to cite this document as other than a work in progress. A Unicode Standard Annex (UAX) forms an integral part of the Unicode Standard, but is published online as a separate document. The Unicode Standard may require conformance to normative content in a Unicode Standard Annex, if so specified in the Conformance chapter of that version of the Unicode Standard. The version number of a UAX document corresponds to the version of the Unicode Standard of which it forms a part. Please submit corrigenda and other comments with the online reporting form [Feedback]. Related information that is useful in understanding this annex is found in Unicode Standard Annex #41, "Common References for Unicode Standard Annexes." For the latest version of the Unicode Standard, see [Unicode]. For a list of current Unicode Technical Reports, see [Reports]. For more information about versions of the Unicode Standard, see [Versions]. For any errata which may apply to this annex, see [Errata].

Increasing the pervasiveness of vegetated surfaces in urban areas has significant value for the a... more Increasing the pervasiveness of vegetated surfaces in urban areas has significant value for the aesthetic and environmental improvement of our cities. Roadways, parking lots, and building roofs offer the most significant untapped areas for urban landscaping. This report will ...

The design-performance space denotes a virtual space that can be constructed based on discretized... more The design-performance space denotes a virtual space that can be constructed based on discretized design variables and performance indicators. For an n-dimensional design-performance space, n = d + p,whereby d = the number of discrete design variables, and p = the number of discrete performance indicators. Once constructed, this space can be visualized and used by the designer to explore the relationship between design variables and corresponding performance attributes. We present, for the building design domain, an approach to generation and exploration of the design-performance space. In this approach, an initial design is used to generate a set of alternative designs that collectively constitutethe design space. One way of doing this relies on the "scalarization" of design variables. The scalarization leads to the representation of a building as a point in a d-dimensional design space. Each coordinate ofsuch a space accommodates a salient (semantic or geometric) design ...

This paper proposes a method comprising procedures to calibrate an EnergyPlus whole building ener... more This paper proposes a method comprising procedures to calibrate an EnergyPlus whole building energy model. An occupant behavior data mining procedure is developed and tested in an office building. Workday occupancy schedules are generated by mining the office appliance energy consumption data. Hourly and monthly power, energy, and temperature data are collected and used for lighting, equipment and HVAC systems energy performance calibration. The result shows a 1.27% mean bias error for the total annual energy use intensity. The proposed calibration method provides a scientific and systematic framework to conduct high accuracy EnergyPlus model calibration.

An International Perspective on the Office of the Future. A Framework for Designing and Managing ... more An International Perspective on the Office of the Future. A Framework for Designing and Managing the Office of the Future. A Process for the Field Evaluation of Advanced Office Environments. Japan's Rapid Approach to the Office of the Future. Toshiba Headquarters. NTT Twins Regional Headquarters. ARK Mori Building. Umeda Center Building. Glimpses of Invention. Major Design Changes for the Office of the Future. Appendices.

IOP Conference Series: Earth and Environmental Science, 2019

Earthen building materials offer an environmentally sustainable alternative to conventional mater... more Earthen building materials offer an environmentally sustainable alternative to conventional materials because they are locally available, minimally processed, and waste-free. However, they have not been comprehensively implemented because their technical data is highly variable, and they are not fully represented in building codes. To address these hurdles, this paper presents an environmental assessment and a policy repair review, including an environmental embodied impact analysis, and a discussion of the regulatory development required for earthen construction. The results of the environmental assessment show that earthen wall assemblies significantly reduce environmental impacts by 62-99% when compared with conventional assemblies such as timber frame and concrete blocks. Additionally, the policy discussion provides recommendations to overcoming materials variability and regulatory organizational collaboration. Overall, this paper highlights the importance of environmental and p...

Healthy, Intelligent and Resilient Buildings and Urban Environments, 2018

A change-point (piecewise linear regression) model fitted to the pre-retrofit data as the counter... more A change-point (piecewise linear regression) model fitted to the pre-retrofit data as the counterfactual for the savings calculation, is considered to be the best approach to evaluating the energy savings of building retrofits (ASHRAE Guideline 14). However, when applied to a large portfolio savings analysis with substantial multi-year data, the change-point model does not fit the data well in some cases. The study thus aims to improve the accuracy of the changepoint model by: 1) using more advanced non-linear models, 2) incorporating additional input features, and 3) increasing the time resolution of input variables. We found that random forest regression (RF) models with an array of climate (humidity, wind, solar radiation, etc.), time (day of the week, season, holiday), and energy consumption of the immediate past 1-4 hours (energy lag terms) outperformed the change-point model, shallow neural networks, and support vector machine regression (SVR). Our result implies that high resolution smart meter data should be used in place of monthly utility bills to more accurately evaluate retrofit savings. We further explored the relative contribution of the input variables to the random forest regression model using Shapley Value, a game theoretic variable importance metric. We found that the most important input feature is the energy consumption of the immediate past (or energy lag terms). We also found that solar radiation and weekend day indicators are more important than outdoor temperature. The improved model could provide better insights to portfolio managers in planning future energy retrofits. Policy makers could also use such models to evaluate the average energy saving potential for energy policy changes, such as the requirement of minimum insulation level, and lighting equipment efficiency.

Springer eBooks, Oct 26, 2006

On average, Americans spend 90% of their time indoors, and it is estimated that indoor pollutant ... more On average, Americans spend 90% of their time indoors, and it is estimated that indoor pollutant levels can be two to five times higher than outdoor levels. Rosenkranz Hall incorporates environmental controls, such as local task lighting, bi-level light switching, and access to thermostats to allow occupants to adjust visual and thermal conditions to their preferences. Materials and finishes with low Volatile Organic Compound (voc) content were chosen to reduce exposure to unhealthy air particulates, maintain excellent air quality, and preserve occupant health. Wood materials do not contain any added urea-formaldehyde, and paints and carpets were selected to have low voc content.

Environmental Health Perspectives, Jun 1, 2007

Journal of the Acoustical Society of America, May 1, 2002

Lack of speech privacy has been reported to be the main dissatisfaction among occupants in open w... more Lack of speech privacy has been reported to be the main dissatisfaction among occupants in open workplaces, according to workplace surveys. Two speech privacy measurements, Articulation Index (AI), standardized by the American National Standards Institute in 1969, and Speech Privacy Noise Isolation Class (NIC′, Noise Isolation Class Prime), adapted from Noise Isolation Class (NIC) by U. S. General Services Administration (GSA) in 1979, have been claimed as objective tools to measure speech privacy in open offices. To evaluate which of them, normal privacy for AI or satisfied privacy for NIC′, is a better tool in terms of speech privacy in a dynamic open office environment, measurements were taken in the field. AIs and NIC’s in the different partition heights and workplace configurations have been measured following ASTM E1130 (Standard Test Method for Objective Measurement of Speech Privacy in Open Offices Using Articulation Index) and GSA test PBS-C.1 (Method for the Direct Measurement of Speech-Privacy Potential (SPP) Based on Subjective Judgments) and PBS-C.2 (Public Building Service Standard Method of Test Method for the Sufficient Verification of Speech-Privacy Potential (SPP) Based on Objective Measurements Including Methods for the Rating of Functional Interzone Attenuation and NC-Background), respectively.

Springer eBooks, 2013

Diminishing natural resources, increasing levels of carbon emissions from the transformation of r... more Diminishing natural resources, increasing levels of carbon emissions from the transformation of raw materials into products, and the growing demand for consumable materials are factors that raise the question "how can a balance between the need for development and the protection of natural resources be created"? As a large share of the energy consumption is related to buildings, analysing the role of advanced materials in architecture and its contribution to sustainability is essential. This paper discusses nanotechnology's promise of lower energy and raw material consumption, reduced waste, greater safety and a healthier environment in the context of sustainable architecture. Nanotechnology is an expanding and innovating area of research and in architecture, it will greatly impact construction materials since the fundamental properties of materials like surface-to-mass ratio, elasticity, conductivity and strength can be controlled at nanoscale. Products like high-insulating panels, self-cleaning and heat-absorbing windows will influence the building industry as such materials have the potential to improve the energy efficiency, durability, economy and sustainability of the built environment. Nano insulating coatings are more efficient than traditional insulators and have a lesser environmental impact. As they can be used for the renovation of existing buildings, they increase the potential of reuse without the aesthetic and functional compromises often required by thick layers of insulation. This paper investigates the application areas of nanomaterials in the construction industry, illustrated with case studies. Investigating the opportunities and challenges provides the basis for the successful implementation and development of these materials.

Springer eBooks, 2013

series (ESST) addresses the grand challenge for science and engineering today. It provides unprec... more series (ESST) addresses the grand challenge for science and engineering today. It provides unprecedented, peer-reviewed coverage in more than 600 separate articles comprising 20 topical volumes, incorporating many updates from the first edition as well as new articles. ESST establishes a foundation for the many sustainability and policy evaluations being performed in institutions worldwide. An indispensable resource for scientists and engineers in developing new technologies and for applying existing technologies to sustainability, the Encyclopedia of Sustainability Science and Technology series is presented at the university and professional level needed for scientists, engineers, and their students to support real progress in sustainability science and technology. Although the emphasis is on science and technology rather than policy, the Encyclopedia of Sustainability Science and Technology series is also a comprehensive and authoritative resource for policy makers who want to understand the scope of research and development and how these bottom-up innovations map on to the sustainability challenge.

Energy for Sustainable Development, Aug 1, 2016

Energy consumption in Indian building sector is increasing at high rate. The National Building Co... more Energy consumption in Indian building sector is increasing at high rate. The National Building Code of India specifies a narrow comfort temperature range between 21 ºC and 26 ºC for all types of buildings and for all seasons. A thermal comfort field study was conducted in 32 naturally ventilated buildings, collecting a total of 2610 samples spread over a total period of four years, covering multiple seasons, age groups, clothing types and building types. Questionnaires were administered to building occupants to record sensations and preferences for air temperature, relative humidity and air velocity on ASHRAE seven point and five point scales. The objective of the study was to evaluate thermal comfort of occupants and study the methods of thermal adaptation such as adjusting clothing, window opening, and use of air circulation fans. Griffith's method was used to determine thermal neutrality. The comfort temperature for summer and winter season was found to be 30.6 ºC and 25.2 ºC, respectively. Preferred clothing level for summer was found to be 0.30 clo, whereas in winter it was 0.80 clo. Preferred air velocity was observed as 0.62 m/s in summer season and 0.27 m/s in winter. Controlling air velocity has been found to be preferred method of thermal adaptation over adjusting clothing and window opening.

Building and Environment, Nov 1, 2016

Thermal comfort standards such as ASHRAE 55-2013 defines comfort boundaries which are based on th... more Thermal comfort standards such as ASHRAE 55-2013 defines comfort boundaries which are based on the experimental results conducted in climatic chambers and field studies. The current comfort standards do not reflect the cultural and climatic diversity of India. A thermal comfort field study was conducted in 32 naturally ventilated buildings, collecting a total of 2610 samples spread over a total period of four years, covering all seasons, wide age groups, clothing types, and building types. In the present study, ASHRAE comfort boundaries at three different air speeds-still air (up to 0.2 m/s), natural air flow (0.2 m/s-0.5 m/s) and forced air flow with ceiling fan assist (0.5 m/s-1.5 m/s) are investigated. The method of calculation suggested by the ASHRAE 55-2013 and ISO-7730 were followed to determine extended acceptable temperature ranges for comfort at elevated air speed. Comfort boundaries are defined based on climate specific adaptations, the role of air speed and thermal preferences. Results from this study indicate that subjects in naturally ventilated buildings of this region are comfortable at temperatures different from those suggested by ASHRAE 55 and ISO-7730 standards. New extended boundaries of comfort zones are proposed considering various adaptations specific to this region, including the role of air speed to offset the temperature. The proposed comfort zones show that subjects are comfortable up to 32˚C at still air condition (0 m/s-0.2 m/s) and up to 35˚C at higher speed (up to 1.5 m/s) in naturally ventilated buildings in the composite climate of India.

Architecture on the 16th of May 1975, in partial fulfillment of the requirements for the degree o... more Architecture on the 16th of May 1975, in partial fulfillment of the requirements for the degree of Master of Architecture. Architecture must be conciously and precisely designed to integrate the life of its occupants with the cycles of nature. This thesis is a collection of information on the natural microclimate which exists on the untouched land, and that which could predominate by intervention and design. An understancing of site potentials and limitations involves: first the survey of local climate elements, second the evaluation of each climatic impact in physiological terms, and third the development of a design response for each microclimate condition. Field reconnaissance gives an invaluable overall picture to the designer, enabling him to design with respect for the site. What is proposed here is a method, an index, for reestablishing in bui/t form, a more delicate exchange between man and nature. The information is organized and presented in such a way that the thesis may be used as a handbook by the architect, engineer, contractor, or homeowner who is interested in making more sympathetic and creative use of a building site.