Office buildings in hot humid Singapore appear to be designed for stable and uniform indoor conditions. It is proposed in this thesis that this is unnecessary, as occupant comfort expectations do not warrant it and energy is wasted as a result. A comfort-based approach to design is advocated, as a means of balancing user needs with the objective of energy conservation.This issue of how perception of comfort is linked with indoor stability emerged from the question, 'why do office buildings, despite Bioclimatic prescriptions for hot humid conditions, continue to be predominantly climate rejecting and active-run?' The literature was found to be polarised by arguments for architectural solutions that are climatically responsive and present lower energy costs, and those for engineered solutions that deliver greater, more consistent comfort, albeit through reliance on electro-mechanical systems.It is argued that comprehending the gaps in the literature, and between theory and application, requires a better understanding of occupant comfort. This would be an inside-out view of comfort and climate, predicated on how the occupant is affected by the building and the cognitive nature of comfort itself.Relying on a sample of office buildings, the thesis set out to establish the following:Prevalence of the climate-based approach, specifically Yeang's Bioclimatic ModelPrevalence of uniformity and stability of the indoor environmentOccupant perception of indoor comfort, both thermal and visual, particularly with regard to variability of ambient conditionsOccupant perception of various operational modes: passive, mixed and activeThese goals were addressed through observations of form, envelope and layout, occupant surveys and the monitoring of buildings in passive and active modes.It was found that the Bioclimatic approach is non-existent in the context of the Singapore office ++ / building. In the case of two Bioclimatic buildings in Malaysia, the Model is not consistently applied. This disparity appears partly due to conflicting priorities, in particular style, cost and client pressures, and partly due to assumptions about occupant comfort.The Singapore office building was found to be predominantly active-run, operating within a narrow bandwidth of temperatures across most spaces. Occupant perception of variability outside the primary workplace, however, is one of acceptance, even preference. It was found through analysis of user feedback that the office building, on the basis of comfort expectations, could be divided into three activity zones: Work, Support and Transit.This 3-tiered structure was subsequently tested through a large-scale, longitudinal survey carried out across three spaces, each representing an activity zone, within a single building. The survey was accompanied by adjustments to the building's temperature settings to test the limits of acceptance in each zone. Findings from this exercise support the notion of a three-zoned office building, in which thermal conditions for each zone could be varied without affecting comfort. Energy figures that were monitored before and after the resetting showed drops of 7.1 % in chiller consumption and 2.9% in overall consumption.These findings led to a comfort-based, tri-modal proposal for office buildings in hot humid conditions, defined as the Psychoclimatic Model for its basis in comfort expectations and the interaction between climate, building and the occupant.The implications of the thesis outcome on regulatory control in Singapore and thermal comfort theory are discussed. Recommendations are made for future research into other building types and national context, plus a parametric study into the full energy-saving potential of the Psychoclimatic Model.

The indoor environmental quality (IEQ) of buildings can have a strong influence on occupants’ productivity and health. Post occupancy evaluation (POE) is the first step in assessing IEQ, and typically relies on subjective surveys of thermal quality, air quality, visual quality, and acoustic quality. However, the practice of conducting POE, from data collection during field studies to data coding, analyses and visualization, is very labor intensive. In addition, there is often a significant discrepancy between major IEQ standards and actual human perception. The Center for Building Performance and Diagnostics (CBPD) at Carnegie Mellon University (CMU) has expanded POE to include both objective IEQ measurements and records of the TABS that may affect indoor environment and user satisfaction. The suite of three tools including user satisfaction survey, technical attributes of building system and workstation IEQ measurements in the National Environmental Assessment Toolkit has been deployed in over 1600 workstations in 65 buildings, generating a rich database for statistical evaluation of the possible correlations between the physical attributes of workstations, measured environmental conditions, and user satisfaction. The database also supports a number of critical hypotheses relative to the complexity and depth of field data needed, the critical factors that must be collected, and the possibility that humans are indeed good sensors for many variables. The major statements that have been drawn from the research are as follows: (1) Because human health and performance outcomes are a result of an integration of indices, IEQ evaluation must include thermal, air, visual, and acoustic measures. (2) While POE with IEQ measurement is an ideal approach to assessing the full suite of environmental characteristics that impact human satisfaction, health and performance, field measurements are labor and cost intensive. (3) Building occupants can provide critical insights and even real measures of IEQ, and contribute to updating IEQ standards to reflect integrated realities. As such, this research revealed an integrated approach to POE +M by leveraging occupants as sensors to quickly capture IEQ conditions in a work environment. This approach can identify critical factors in the physical environment that impacts building occupant comfort and satisfaction. This approach provides practical IEQ assessment methods and procedures centered on the occupants’ perspective. The ultimate outcome of this research will contribute (1) correlations between occupant perception and measured data, (2) a refined survey method to assess building IEQ capable of robust prediction of building performance, and (3) metrics and guidelines for IEQ standards that capture new IEQ thresholds that impact building occupants’ comfort. The hypotheses tested in this thesis are summarized as follows: Hypothesis 1: Humans are effective sensors for POE+M. Combining occupant responses with key IEQ attributes can provide insight that is comparable to complex field instrumentation. Hypothesis 2: User satisfaction can inform design decisions. Comparing user satisfaction to instrumented IEQ measurements can inform acceptable thermal, air, visual, and acoustic design for occupant satisfaction. Hypothesis 3: Environmental thresholds are not adequate. Comparing user satisfaction to instrumented IEQ measurements can inform acceptable thermal, air, visual, and acoustic quality l conditions for occupant comfort. Multivariate regression, multiple correlation coefficient, and Pearson correlation statistical analysis of the database of 1600 workstations revealed the relationship between measured and perceived IEQ indices, interdependencies between IEQ indices and other satisfaction variables of significance. This research can contribute correlations between occupant perception and measured conditions, and metrics and guidelines for IEQ standards that capture new IEQ thresholds that impact building occupants’ comfort. The key findings of the IEQ data analysis are as follows: The result of the thermal quality revealed that smaller thermal zone, greater window quality, a level of control, measured air temperature at 60 cm from the floor, and radiant temperature asymmetry between exterior and interior walls are critical factors of temperature satisfaction. For air quality, operable windows, window quality, partition height, dedicated exhausts for printer and copy area, return air density are critical factors for overall air quality satisfaction. User satisfaction of the visual quality showed that seated view in the workstation is the most critical factor for user’s overall visual quality satisfaction. In addition, better ceiling fixture, ceiling lens type, window type and managing illuminance level on the work surface are important. Lastly, to ensure the acoustic quality satisfaction in both background noise and frequency from distraction from other people, bigger workstation, more partition sides, higher partitions and management of distributed noise source are critical for user comfort and perceived productivity. Overall, this thesis identified opportunities to improve the process of IEQ assessment by engaging occupants in POE, and define critical indicators for building occupant satisfaction. The results will contribute to the ongoing database of engaging humans as IEQ sensors. In the future, the findings and framework described here may be applied in different aspects of the building delivery process, such as building life cycle evaluation, building design, and the construction stage, to improve occupants’ thermal, air, visual, and acoustic conditions in the building.

In recent decades, much research has investigated the efficiency of Phase Change Materials (PCMs) in improving the thermal performance of buildings and pavements. In buildings, increasing the thermal inertia of structural elements by incorporating PCMs decreases the energy required to keep the inside temperature in the comfort range. In concrete pavements, using PCMs decreases the number of freeze/thaw cycles experienced by the pavement and thus increases service life. However, PCMs cannot be added to cementitious binders directly, because they interfere with the hydration reactions between cement and water that produce strength-bearing phases. Therefore different carriers have been proposed to indirectly incorporate PCMs in cementitious materials. Lightweight Aggregate (LWA) is one of the materials that has been proposed as PCM carrier agent. However, it was not studied in depth before. Various experiments were conducted to investigate the problems associated with incorporating LWA presoaked in PCM in cementitious media. The results show that a portion of PCM leaks out of the LWA’s structure and subsequently affects different chemical, physical, and mechanical properties of the binder. In addition, the applicability of Rice Husk Ash (RHA), a common material never before used to encapsulate PCM, as a PCM carrier agent was investigated. The results show that RHA can absorb and contain liquids in its porous structure; and regarding its compatibility with the cementitious media, it can be used as PCM carrier. Different computational simulations using Typical Meteorological Year data were conducted to evaluate the efficiency of PCMs in improving the thermal performance of buildings. Utilizing PCM-incorporated gypsum boards was shown to be a promising strategy to achieve the governmental plans of “Zero Net Energy� buildings. The results show that using a PCM with a melting point near the occupant comfort zone delays and reduces the inside peak temperature, increases the duration of time during which the inside temperature stays in the comfort zone, and decreases the cost and energy required by HVAC system to keep the inside temperature in this range. However, PCMs’ efficiency is completely dependent on the input temperature profile.

abstract: Through manipulation of adaptable opportunities available within a given environment, individuals become active participants in managing personal comfort requirements, by exercising control over their comfort without the assistance of mechanical heating and cooling systems. Similarly, continuous manipulation of a building skin's form, insulation, porosity, and transmissivity qualities exerts control over the energy exchanged between indoor and outdoor environments. This research uses four adaptive response variables in a modified software algorithm to explore an adaptive building skin's potential in reacting to environmental stimuli with the purpose of minimizing energy use without sacrificing occupant comfort. Results illustrate that significant energy savings can be realized with adaptive envelopes over static building envelopes even under extreme summer and winter climate conditions; that the magnitude of these savings are dependent on climate and orientation; and that occupant thermal comfort can be improved consistently over comfort levels achieved by optimized static building envelopes. The resulting adaptive envelope's unique climate-specific behavior could inform designers in creating an intelligent kinetic aesthetic that helps facilitate adaptability and resiliency in architecture. / Dissertation/Thesis / Ph.D. Environmental Design and Planning 2013

No description available.

<p dir="ltr">As the urbanization trend prevails worldwide, more people are moving to major metropolitan areas, causing housing resources to be in urgent demand. Tiny homes, designed to offer a minimalist lifestyle while also addressing growing housing needs, have become increasingly popular among home seekers. Since the COVID-19 outbreak, individuals primarily spend their time indoors, and with more people adopting work-from-home lifestyles, ensuring a high-quality, sterile, and comfortable indoor environment becomes crucial for indoor occupants. Many studies have highlighted that the activities of occupants significantly influence indoor environmental quality (IEQ) and energy consumption in buildings and applying disinfectants will generate increasing amount of volatile organic compounds (VOCs) which occupants could inhale, causing adverse health effects. Within this thesis, two studies are introduced and discussed. The first study, namely “zEDGE Living Experiments,” conducts a comprehensive evaluation of IEQ satisfaction and energy usage in the Purdue zEDGE Tiny House through real-time measurement and survey analysis. Twenty full-scale experiments were conducted during the winter season. The study first evaluates participants’ perception of IEQ factors, with thermal comfort and indoor air quality (IAQ) emerging as top priorities. It then examined energy adaptive behavior to understand maintenance of comfortable indoor conditions, noting primary adaptive strategies including heating, ventilation, and artificial lighting. The study then measured IEQ and energy consumption, evaluating occupants’ IEQ satisfaction levels. The average energy use was recorded at 10.3 kWh, with occupants generally satisfied with IEQ in the zEDGE Tiny House. Analysis indicated that heating and cooking were significant energy consumers, potentially exposing occupants to high indoor air pollutant levels in such compact living spaces. The second campaign, namely “Performance Evaluation of PID and PTR-TOF-MS,” compares the VOC detection abilities of photoionization detectors (PID) and a state-of-the-art proton-transfer-reaction time-of-flight mass spectrometer (PTR-TOF-MS). 54 controlled emission experiments were carried out among 18 different disinfectant products with main ingredients based on alcohol, lactic acid, peracetic acid/acetic acid, and botanical products. The results from time-series and correlation analyses indicate that the PID and PTR-TOF-MS were able to detect VOC signals from emission experiments. While the performances of the PID and PTR-TOF-MS were similar under experiments with alcohol-based products, the PID performed less well with products based on lactic acid and botanical products, and unsatisfactory for peracetic acid/acetic acid-based products.</p>

<p>The research is aimed in order to increase the efficiency and improve the<br />energy performance of multi-level administrative buildings in temperate<br />climate conditions. Special emphasis is on achieving and maintaining<br />acceptable indoor environmental standards and thermal comfort of<br />occupants. The investigation is based on a complex multi-criteria optimization<br />utilizing the most contemporary technology of dynamic energy simulations.<br />The developed methodology for energy performance evaluation and<br />improvement in the function of occupant comfort will have the possibility of<br />application on similar and newly designed buildings. The formulated model<br />also possesses flexibility and adaptability for further improvement and<br />application in different climatic conditions.</p> / <p>Истраживање је усмерено на повећање ефикасности и унапређење енергетских перформанси вишеспратних административних зграда у умереним климатским условима. Посебан нагласак је на постизању и одржавању прихватљивих унутрашњих микроклиматских стандарда и термичког комфора корисника. Истраживања су заснована на комплексној вишекритеријумској оптимизацији уз примену најсавременије технологије динамичке енергетске симулације. Развијена је методологија, флексибилна и прилагодљива, за вредновање и унапређење енергетских перформанси у функцији корисничког комфора, за примене и на друге сличне и новопројектоване објекте. Формулисан модел је подобан за даља унапређења и примену у различитим климатским условима.</p> / <p>Istraživanje je usmereno na povećanje efikasnosti i unapređenje energetskih performansi višespratnih administrativnih zgrada u umerenim klimatskim uslovima. Poseban naglasak je na postizanju i održavanju prihvatljivih unutrašnjih mikroklimatskih standarda i termičkog komfora korisnika. Istraživanja su zasnovana na kompleksnoj višekriterijumskoj optimizaciji uz primenu najsavremenije tehnologije dinamičke energetske simulacije. Razvijena je metodologija, fleksibilna i prilagodljiva, za vrednovanje i unapređenje energetskih performansi u funkciji korisničkog komfora, za primene i na druge slične i novoprojektovane objekte. Formulisan model je podoban za dalja unapređenja i primenu u različitim klimatskim uslovima.</p>