Design optimisation study of indoor environments in student dormitories with enclosed balconies through multi-algorithm integration

This research aims to develop user-focused design principles for energy-efficient office renovations. The goal of this is to improve the quality and comfort of workspaces without compromising on energy-saving goals. Due to increasing sustainability requirements, new ways of working and changing office user preferences, there is a growing need for office renovations that not only deal with the energy performance and the replacement of building facilities, but also the occupants’ health and well-being. The renovation of office buildings can substantially reduce energy demand and improve building performance. For this reason, most studies regarding office renovations have focused on achieving better energy performance and indoor environmental quality. Also, several studies have investigated employee satisfaction in the work environment. However, the users are only considered after the buildings have been built and taken into use (e.g., postoccupancy evaluation), but not in the early stage of the design phase. Although there are building regulations and norms regarding indoor comfort, no clear design principles or guidelines considering users have been developed for office renovations. Therefore, it is necessary to explore how office users can be included in the early design stage of office renovations to improve their comfort and satisfaction. This led to the following main research question to be answered in this thesis: How can design principles for energy efficient office renovation be developed, based on the evaluation of user satisfaction? To answer to this question, field studies were conducted in 5 office buildings in the Netherlands. The cases consist of four renovated offices and one non-renovated office, originally built in 1960s to 70s. Before conducting empirical studies, a literature was conducted that is implemented in the theoretical framework. Ten parameters for satisfaction, such as thermal comfort, air quality, light, noise, personal control, privacy, concentration, communication, social contact, and territoriality, were defined and were classified based on the findings from 124 items of studies focussing on physical and psychological satisfaction in the work environment. Each chapter and several sub-research questions address these parameters. Based on the findings, a classification of user satisfaction parameters is proposed, including a discussion about an hierarchy of ten parameters. This hierarchy is structured based on theoretical definitions of parameters and its physical, functional, and psychological influences. For the empirical studies, a multidisciplinary methodology was applied to prioritise the important aspects of office renovations. The various methods for data collection and analyses included examining energy use and the quality of indoor climate after renovation, and investigating the impact of design factors on user satisfaction with thermal, visual, and psychological comfort. The design factors in this research are influential design factors on user satisfaction. These are office layout, orientation, window-to-wall ratio, and desk location. The empirical studies are structured in four parts. Energy consumption As a preliminary study, architects and facility managers were interviewed to identify the building characteristics of renovated offices and energy consumption. Henceforth, the five case studies were conducted. A cross-case-analysis was used to compare the building characteristics of the five case studies. The energy consumption of renovated and non-renovated offices were compared by different energy matrix. In addition, the limitations that hinder the achievement of better energy performance, were described. Indoor climate and users’ thermal comfort Indoor temperature and humidity were measured by using data loggers to identify the condition of the indoor climate for users’ thermal comfort after renovation. A questionnaire, including thermal sensation, preference, and satisfaction, was distributed among the building users. The monitored climate data of the thermal conditions were evaluated based on the Dutch building norms and users’ responses. Personal control This part aims to identify the relationship between the degree of personal control over indoor environmental conditions (e.g., temperature, ventilation, light) and user satisfaction with thermal and visual comfort. This study investigated the impact of personal control on user satisfaction through user surveys and statistical analyses. The results present that higher controllability leads to more satisfaction in terms of thermal and visual comfort. It also reveals the psychological impact of personal control on user satisfaction by showing differences in perceived satisfaction according to ‘no control’ and ‘do not have’. These findings provide support to workplace management and the design of personal environmental control systems. User satisfaction with thermal, visual, and psychological comfort Together with the indoor climate conditions of workspaces, 579 office users from the five cases were studied. The responses of the users were collected and analysed through statistical analyses. This study phase demonstrates the results of the impact of influential office design factors on user satisfaction with thermal, visual, and psychological comfort. It also contributes to predicting which design variables may bring better user satisfaction. After the empirical studies, the conceptual study was conducted through energy simulation to evaluate the impact of the combination of design factors on the energy demand. Twenty-four office model variants were created based on the combination of design factors, which are consisted of 3 or 4 variables. The energy demand is predicted according to the office model variants. As a next step, the design principles were developed by incorporating the previous findings and various perspectives of energy-efficient office renovation. An overview of the predicted user satisfaction and energy demand is graphically provided in this research. Based hereupon, a flow chart is created for applying the principles to the renovation process. First, the most influential design factors on thermal, visual, and psychological satisfaction are suggested in the design principles. Next, the values of predicted user satisfaction and energy demand can be evaluated by following the flow chart, to find the optimal renovation plan. In this step renovation alternatives are suggested in terms of office variants to create a balance between user satisfaction and energy efficiency. Last, if design limitations occur, the degree of personal control should be included to increase user satisfaction. The comprehensive design principles can help architects, designers, and facility managers to make design decisions in an early stage of office renovations. To summarise, this research demonstrates the relationship between design factors, indoor climate and user satisfaction, without neglecting the fundamental goal of office renovation: reducing the energy demand, upgrading facilities, and improving building performance. It also contributes to developing design principles for office renovations with integrated user perspectives, that improve users’ satisfaction and comfort, as well as energy efficiency. Although users’ individual control over the indoor environment has a significant impact on satisfaction, it needs to be explored further. In addition, it is important to mention that other variables such as building elements and various façade configurations need to be included in further research. In conclusion, design principles considering both energy efficiency and user satisfaction will not only contribute to an increase in the value of a building, but also serve as a stepping stone for user-focused office designs or user-related aspects of the built environment.

This research aims to develop user-focused design principles for energy-efficient office renovations. The goal of this is to improve the quality and comfort of workspaces without compromising on energy-saving goals. Due to increasing sustainability requirements, new ways of working and changing office user preferences, there is a growing need for office renovations that not only deal with the energy performance and the replacement of building facilities, but also the occupants’ health and well-being. The renovation of office buildings can substantially reduce energy demand and improve building performance. For this reason, most studies regarding office renovations have focused on achieving better energy performance and indoor environmental quality. Also, several studies have investigated employee satisfaction in the work environment. However, the users are only considered after the buildings have been built and taken into use (e.g., postoccupancy evaluation), but not in the early stage of the design phase. Although there are building regulations and norms regarding indoor comfort, no clear design principles or guidelines considering users have been developed for office renovations. Therefore, it is necessary to explore how office users can be included in the early design stage of office renovations to improve their comfort and satisfaction. This led to the following main research question to be answered in this thesis: How can design principles for energy efficient office renovation be developed, based on the evaluation of user satisfaction? To answer to this question, field studies were conducted in 5 office buildings in the Netherlands. The cases consist of four renovated offices and one non-renovated office, originally built in 1960s to 70s. Before conducting empirical studies, a literature was conducted that is implemented in the theoretical framework. Ten parameters for satisfaction, such as thermal comfort, air quality, light, noise, personal control, privacy, concentration, communication, social contact, and territoriality, were defined and were classified based on the findings from 124 items of studies focussing on physical and psychological satisfaction in the work environment. Each chapter and several sub-research questions address these parameters. Based on the findings, a classification of user satisfaction parameters is proposed, including a discussion about an hierarchy of ten parameters. This hierarchy is structured based on theoretical definitions of parameters and its physical, functional, and psychological influences. For the empirical studies, a multidisciplinary methodology was applied to prioritise the important aspects of office renovations. The various methods for data collection and analyses included examining energy use and the quality of indoor climate after renovation, and investigating the impact of design factors on user satisfaction with thermal, visual, and psychological comfort. The design factors in this research are influential design factors on user satisfaction. These are office layout, orientation, window-to-wall ratio, and desk location. The empirical studies are structured in four parts. Energy consumption As a preliminary study, architects and facility managers were interviewed to identify the building characteristics of renovated offices and energy consumption. Henceforth, the five case studies were conducted. A cross-case-analysis was used to compare the building characteristics of the five case studies. The energy consumption of renovated and non-renovated offices were compared by different energy matrix. In addition, the limitations that hinder the achievement of better energy performance, were described. Indoor climate and users’ thermal comfort Indoor temperature and humidity were measured by using data loggers to identify the condition of the indoor climate for users’ thermal comfort after renovation. A questionnaire, including thermal sensation, preference, and satisfaction, was distributed among the building users. The monitored climate data of the thermal conditions were evaluated based on the Dutch building norms and users’ responses. Personal control This part aims to identify the relationship between the degree of personal control over indoor environmental conditions (e.g., temperature, ventilation, light) and user satisfaction with thermal and visual comfort. This study investigated the impact of personal control on user satisfaction through user surveys and statistical analyses. The results present that higher controllability leads to more satisfaction in terms of thermal and visual comfort. It also reveals the psychological impact of personal control on user satisfaction by showing differences in perceived satisfaction according to ‘no control’ and ‘do not have’. These findings provide support to workplace management and the design of personal environmental control systems. User satisfaction with thermal, visual, and psychological comfort Together with the indoor climate conditions of workspaces, 579 office users from the five cases were studied. The responses of the users were collected and analysed through statistical analyses. This study phase demonstrates the results of the impact of influential office design factors on user satisfaction with thermal, visual, and psychological comfort. It also contributes to predicting which design variables may bring better user satisfaction. After the empirical studies, the conceptual study was conducted through energy simulation to evaluate the impact of the combination of design factors on the energy demand. Twenty-four office model variants were created based on the combination of design factors, which are consisted of 3 or 4 variables. The energy demand is predicted according to the office model variants. As a next step, the design principles were developed by incorporating the previous findings and various perspectives of energy-efficient office renovation. An overview of the predicted user satisfaction and energy demand is graphically provided in this research. Based hereupon, a flow chart is created for applying the principles to the renovation process. First, the most influential design factors on thermal, visual, and psychological satisfaction are suggested in the design principles. Next, the values of predicted user satisfaction and energy demand can be evaluated by following the flow chart, to find the optimal renovation plan. In this step renovation alternatives are suggested in terms of office variants to create a balance between user satisfaction and energy efficiency. Last, if design limitations occur, the degree of personal control should be included to increase user satisfaction. The comprehensive design principles can help architects, designers, and facility managers to make design decisions in an early stage of office renovations. To summarise, this research demonstrates the relationship between design factors, indoor climate and user satisfaction, without neglecting the fundamental goal of office renovation: reducing the energy demand, upgrading facilities, and improving building performance. It also contributes to developing design principles for office renovations with integrated user perspectives, that improve users’ satisfaction and comfort, as well as energy efficiency. Although users’ individual control over the indoor environment has a significant impact on satisfaction, it needs to be explored further. In addition, it is important to mention that other variables such as building elements and various façade configurations need to be included in further research. In conclusion, design principles considering both energy efficiency and user satisfaction will not only contribute to an increase in the value of a building, but also serve as a stepping stone for user-focused office designs or user-related aspects of the built environment.

A higher educational student spends around 3-8 years in institutional buildings. Thus, it is of a prime importance to maintain proper Indoor Environmental Quality (IEQ) in lecture theatres in higher educational institutions as inadequate IEQ will lead to Sick Building Syndrome (SBS) and Building Related Illnesses (BRI). When it comes to the Sri Lankan context, there are only limited studies done on assessing the IEQ in institutional buildings. Therefore, the purpose of this research is to assess the IEQ of lecture halls by considering various parameters such as indoor air quality, thermal comfort, visual comfort and acoustic comfort for mechanically ventilated lecture halls. This study has investigated whether IEQ of the higher education facilities complies with the American society of heating, refrigerating and air-conditioning engineers (ASHRAE) standard which is the current standard we are using in Sri Lanka for the IEQ assessment. The study has also performed a qualitative assessment of the IEQ through questionnaire surveys with the students and assessed whether it there is a co-relation with the IEQ and SBS. Five different lecture theatres of different indoor environmental conditions at University of Sri Jayewardenepura, Faculty of Applied Sciences premises were selected to carry out the investigation. Different IEQ parameters such as thermal comfort, indoor air quality, visual comfort and acoustic comfort were measured with using specific instruments. Quantitative data collection was done throughout a semester and qualitative data collection was done using a questionnaire. A statistical data analysis was conducted to assess whether there are co-relations between the IEQ and the SBS symptoms for the particular lecture halls.The results have shown that some of the lecture theatres have exceeded standard values of indoor CO2 levels when compared to the ASHRAE standards. However, it could be improved by allocating the students with the proper occupant density.There were some disturbances to the acoustic comfort in certain lecture halls due to some ventilation machineries. The results of this study could be used for the future improvements in designing of the lecture theatres for the higher education facilities in Sri Lanka. Keywords: Indoor environmental quality (IEQ), Sick building syndrome (SBS), Building related illnesses (BRI)

Indoor temperature and humidity conditions as well as CO2 and airborne mould concentrations were measured in four manor schools in the Estonian cold climate. Based on these measurements, the influence of the indoor climate on the performance of schoolwork was assessed. The indoor environmental quality in manor schools turned out to be quite poor due to the inadequate performance of ventilation and heating systems. Intermittent stove heating was found to secure the minimum temperature in general but in winter thermal comfort was not always guaranteed. In addition, temporary overheating resulting in a significant temperature rise in the morning was intended to maintain room temperatures until the afternoon. Overheating in the summer period was not a problem in these schools. Ventilation airflow and indoor air quality were significantly lower in classrooms equipped with natural ventilation, resulting in higher CO2 and airborne mould concentrations and higher humidity loads for the building envelope. Original natural passive stack ventilation and window airing were not suitable solutions for providing the required indoor environmental conditions in cold climate conditions due to the type and efficiency of ventilation, inadequate duct size and air speed in ducts. Using previously published models, the level of schoolwork performance was estimated to be lower (75%…95%) in classrooms with natural ventilation and stove-heating. Air change was significantly higher in classrooms with mechanical exhaust ventilation; however, according to current standards for classrooms, the airflow was too low with both ventilation systems. Occupation density influences the indoor air quality significantly. To fulfil the requirements of indoor climate, pupil density in classrooms must be 2–3 times lower than the current requirement. In order to maintain schools in old manors in a cold climate, special attention should be paid to ensuring indoor environmental conditions. In addition to heritage values, other values, such as schoolwork performance and energy efficiency, should also be used as parameters in the improvement of indoor conditions and building service systems in old manor schools.

This study estimates the relationship between poor indoor environmental quality (IEQ) and the increasing labor costs in green buildings in Taiwan. Specifically, poor performance of IEQ including HVAC, lighting, and indoor air quality, influences the health and well-being of occupants and leads to worse productivity, ultimately causing increased personnel cost. In Taiwan’s green building certification (GBC) system, the energy-savings category is mandatory while the IEQ category is only optional. It means that certified building cases may not reach the expected level in IEQ. Thus, this study reviews the thermal environment, indoor air quality (IAQ), and illumination performances of IEQ-certified and non-IEQ-certified buildings in 20 green buildings. Building energy and IEQ simulations were conducted to analyze the relationships between indoor comfort, energy cost, and personnel cost in green buildings. The results show that IEQ-certified green buildings averagely perform better than non-IEQ-certified ones in the aspects of IEQ and building costs. Besides, 3 of 13 non-IEQ-certified green buildings undertake extremely high additional expenditure for the poor IEQ. The results correspond to some previous findings that green-certified buildings do not necessarily guarantee good building performance. This study further inspects the pros and cons of Taiwan’s GBC system and proposes recommendations against its insufficient IEQ evaluation category. As the trade-off of energy-saving benefits with health and well-being in green buildings has always been a concern, this study aims to stimulate more quantitative research and promote a more comprehensive green building certification system in Taiwan.

Indoor environmental quality in school buildings, and the health and wellbeing of students

Thermal comfort, indoor air quality, lighting comfort, and acoustic comfort are often treated as separate domains, despite interacting trade-offs. The discrete choice experiment (DCE) technique helps to account for explicit and implicit factors influencing choices, giving a more holistic view of indoor comfort. This paper reviews discrete choice experiment studies that include indoor environmental comfort elements. From 1,418 records found in scientific databases, 21 studies were reviewed. By analysing these studies, DCE’s ability to value indoor comfort was evaluated and methodological deficiencies identified. Given the heterogeneity between studies, this review focused on analysing the p-value and the direction of estimates. Thermal comfort in these studies shows positive and statistically significant coefficients, indoor air quality is generally positive but statistically heterogeneous. Evidence for positively valued lighting and acoustic comfort is frequently statistically non-significant. Methodological challenges identified affecting indoor environmental quality (IEQ) valuation in DCEs include proxy dilution, insufficient attribute clarity, embedded cost signals, and demographic heterogeneity. Proxy-based operationalisations may confound comfort valuation with convenience, cost, or multi-domain interaction effects. Additionally, occupant control and agency emerge as meta-attributes that generate utility beyond environmental improvement. Survey-based DCE can reliably elicit thermal comfort preferences from occupants; experiential approaches such as virtual reality-based DCE may allow occupants to better value acoustic and lighting comfort. Overall findings suggest indoor comfort should be modelled as a multi-attribute bundle instead of separate domains. This review shows that DCE is a useful tool for analysing indoor comfort as a bundle of attributes with strong interaction effects.

This paper aims to investigate the indoor environmental conditions and energy use behaviours of older individuals in rural cold climates of China, with a specific focus on cooling practices during the summer months in the Shandong region. This study employs a mixed-method approach, combining quantitative indoor environmental monitoring with qualitative interviews and observations, to explore the relationship between environmental factors, household living conditions, and energy use patterns across five types of elderly households: three generations living together, older people living with grandchildren, older people living with children, older couples living together, and older people living alone. Data collection was conducted over five weeks during the summer of 2023 using HOBO UX100-003 data loggers, while external weather conditions were monitored by the China Meteorological Administration. Face-to-face interviews were conducted to gain deeper insights into daily cooling behaviours and energy use. The results reveal that cooling practices and indoor environmental conditions vary significantly among the different household types. Multigenerational households showed more complex energy use dynamics, with younger family members frequently operating high-energy appliances like air conditioners, while older individuals tended to rely on natural ventilation and electric fans to reduce energy costs. In contrast, older couples and solitary older individuals demonstrated more conservative cooling behaviours, often enduring higher indoor temperatures due to limited financial resources and a desire to minimize energy expenditures. Despite the high energy use intensity in some households, many homes failed to achieve comfortable indoor environments, particularly in dwellings with minimal insulation and older building materials. This study concludes that economic status, household structure, and building characteristics play crucial roles in shaping cooling behaviours and indoor comfort during the summer.

In a recent Indoor Air editorial (Volume 19, Issue 4, 2009), editor Jan Sundell wrote ‘Indoor Air as a journal, as well as indoor air as a science, will die unless we start to co-operate, as Indoor Air and the society behind it, ISIAQ, are all about multidisciplinary science!’ How dire! Whether we consider deleterious effects in complex modern buildings or in rudimentary indoor systems in the developing world, indoor environments are fraught with human health hazards. Our highest goal, then, should not be to recruit lifelong indoor environmental scientists and engineers, but rather to clearly define human health challenges that take root in indoor environments and engage the expertise of teams and individuals from relevant disciplines to address them. Thus, while agreeing with Sundell’s quote, we propose an alternate diction: ‘Indoor environmental science and health research will flourish and progress when members from multiple disciplines collaborate and work toward common goals.’ Multiple disciplines cannot force common goals, yet solutions to problems in our field naturally encourage collaboration. The research questions in our field benefit from the inclusion of specialists from many disciplines, even if they do not focus entirely on indoor environments. Perhaps our field would further prosper by outcome-driven projects relying on many different outside specialists who would come to know the nature of our work in bits and pieces, rather than by convincing a few small groups of researchers to devote their careers to indoor environmental studies. In July 2009, with these collaborative goals in mind, we, the student members of a National Science Foundation (NSF) Integrative Graduate Education and Research Traineeship (IGERT) program in Indoor Environmental Science and Engineering at the University of Texas at Austin gathered to discuss research priorities in our field and to highlight some impending grand challenges we face as emerging indoor environmental scientists, but also as members of a larger, environmentally concerned scientific community. We produced the following list of priorities from a novel, and previously unpublished, perspective: that of students. Develop and implement cost-effective air pollutant control strategies for new and existing buildings that reduce exposure to pollutants and lower by-product formation from chemical reactions without compromising energy consumption in buildings. Anticipate, assess, and address threats to indoor environmental quality (IEQ) that may result as communities develop more densely populated, mixed-use, walkable and transit-served neighborhoods. Engage with policy-makers to establish, enforce, and evaluate codes and voluntary guidelines that enable practitioners and occupants to create and sustain healthy, comfortable, productive, and energy-efficient indoor environments. Develop and promote exposure and risk assessment practices, using quantifiable physiological metrics that include the potential compound and cumulative health effects from exposure to multiple pollutants, including those emitted by traditional and green building materials. Commit to improve IEQ for vulnerable populations lacking political and economic power while recognizing that communities deserve context sensitive solutions since needs vary across nations, regions, and socioeconomic status. Addressing the priorities included here will inevitably lead to transcending the traditional boundaries between disciplines and professions, especially given the emphasis we place on implementation, on-going evaluation, and the needs of vulnerable communities. Our proposed priorities should be read as broad, but certainly not exhaustive, vision statements for an interdisciplinary field: each will require researchable questions developed by specialists working individually and in teams. For instance, we cannot hope to develop effective air pollutant control strategies or risk assessment practices unless we are also (i) investigating novel compounds, often unstable byproducts of chemical reactions, in source fate and transport studies, (ii) linking perceived IEQ studies with toxicological and exposure studies, and (iii) conducting IEQ intervention studies that evaluate occupant behavior and health outcomes alongside changes in indoor chemistry and physics. Whether in the lab or in the field, as practitioners or policy-makers, we find that these broad research goals will help guide us in careers that meaningfully contribute to science and society. As graduate students in an interdisciplinary program, we are well aware that interdisciplinary collaboration is rarely easy. Yet, these tensions are often productive. We have found that interdisciplinary collaboration toward common goals has the added benefit of opening new areas of research, increasing our efficiency in managing other complex problems, and forging partnerships that can be employed to address challenges that we have yet to discover.

Analyses in this study focus on characteristics of three different clusters of ventilation for office buildings. These comprise natural, mechanical and hybrid ventilation. In a major project study, extensive data was collected from 27 office buildings. Besides physically measurable parameters, psycho-social-oriented surveys of building users and information about building-specific constructional or building technology were compiled. In a selection, results of indoor air quality (IAQ) and indoor environment quality (IEQ) were compared with current standards. Thom's Discomfort Index (DI) suggested that, for all three clusters, populations feeling discomfort are to be expected during the summer months. Responses for certain aspects corresponding to IEQ and IAQ showed a remarkable seasonal divergence of satisfaction with air temperature for naturally ventilated buildings. The appearance of stagnant air is found to occur in its strongest form in naturally and hybrid ventilated buildings. Mechanically ventilated buildings were reported as having the lowest values for satisfaction with air humidity in winter. Each ventilation system comprises characteristic advantages and disadvantages. A tendency might favour, at least seasonally, mechanically or hybrid ventilated buildings. Differences between these two systems are not significant in this sample. The result raises the question of how much technical effort is actually necessary to provide satisfactory ventilation.

Indoor environment quality is a relative measure of comfort perception by people exposed to the indoor conditions. It is expected that any assessment of energy performance should also include indoor comfort. This study is to review indoor environmental quality models (with respect to thermal and acoustic comfort, indoor air and lighting quality). A simplified indoor environmental quality model is also developed with consideration of EN 15251 draft ‘Guideline for using indoor environmental input parameters for the design and assessment of energy performance of buildings’. This article analyses what components should be modelled and in particular discusses the effect of different weighting schemes on the overall indoor environmental quality index. The analysis includes thermal comfort models, indoor air quality, acoustic comfort and daylight illumination versus lightning. The proposed indoor environmental quality component sub-models will give the most reliable results when the model indoor environment input data are correctly measured and disturbing influences of indoor environmental quality monitoring process are well defined and properly assessed. The final indoor environmental quality result is based on subjoining the uncertainty values achieved in panel analysis of percentage of persons dissatisfied with indoor environmental quality with corrected measurement uncertainty. All simulations for IEQindex sub-components and preliminary metrological analysis of the whole indoor environmental quality model were performed with the NIST program for Monte Carlo tests. The presented indoor environmental quality model proposal is developed to support engineers’ practice as the convenient tool for a practical assessment of building’s occupational satisfaction.

The impact of space design on occupants' satisfaction with indoor environment in university dormitories

Poor air quality in the dormitory will affect students’ physical and mental health and reduce their learning efficiency. The environmental status of university dormitory is gaining more and more attention. The indoor environment quality is always affected by outdoor condition during the heating period due to the requirement of natural ventilation. Using ANSYS Fluent software establishes a full-scale indoor and outdoor inner-corridor-type dormitory taking into account the different floor numbers. The results revealed that the living area on the south side of the corridor has a higher temperature and carbon dioxide concentration compared with the north side of the corridor. The balcony and corridor play an important role in maintaining the temperature of the dormitory. The mean velocity on the first floor is the lowest, and there is no significant difference in the air velocity in the living area on both sides of the corridor. The living area on the fifth floor has the better ventilation effectiveness. The results of this study will help architects understand the impact of natural ventilation on the indoor environment in inner-corridor-type dormitory.

Poor Indoor Environmental Quality (IEQ) adversely affects the performance and health of building users. Building users are an important source of information regarding IEQ and its influence on users’ wellbeing and productivity. This paper discusses the analysis and evaluation of IEQ in lecture halls of two public Architectural Campus Buildings (ACB) in Karachi, Pakistan. The method of this research is divided into three parts: (i) An analysis of local climate conditions, (ii) An on-site survey of two existing ACBs to analyze indoor environmental conditions. and (iii) The analysis of users’ satisfaction using a questionnaire survey. The research results showed that users are dissatisfied with existing hot and humid indoor environment conditions caused by interactions of local outdoor climate conditions, the building’s architecture, and inadequate ventilation within the building. The findings revealed that Karachi has 41.3% comfort hours with the warm sub-humid season to be the most comfortable season having 80.56% comfort hours. IEQ analysis unveiled that airflow in ACB1 is low, whereas, high airflow is observed in ACB2. The findings of this research unveiled that cross-ventilation by the adapted placement of openings, improved external shading devices, and provision of increased vegetation are required in both ACBs to achieve a more comfortable IEQ.

During the last two decades the significance of indoor environmental quality in buildings has been appreciated, not only in relation to thermal comfort, but also to indoor air quality. Ventilation is an important tool for securing both a good indoor climate and air quality. However, in buildings without mechanical ventilation and air conditioning systems (which comprise the majority in most European countries) natural ventilation presents the only means to satisfy indoor air quality needs. Natural ventilation is, however, a process that is difficult to control, whilst its impact is difficult to quantify by the buildings‘ occupants in real life. A field survey, carried out by the authors, is described in this paper. This highlights both the potential and the constraints of natural ventilation in office buildings. The survey focused on the two main parameters, which determine indoor environmental quality, namely thermal comfort and air quality. The data collection strategies employed were in-situ measurements to determine and evaluate the prevailing conditions, and questionnaires, which monitored and evaluated the perceptions held by the buildings‘ users in relation to those conditions. The latter confirmed the occupants‘ difficulties and dissatisfaction with respect to controlling prevailing thermal comfort conditions, whilst the former demonstrated the role of natural ventilation in reducing CO 2 and particulate matter concentrations. The survey also underlined the ineffectiveness of natural ventilation when attempting to control relative humidity levels and the overall difficulties in achieving a satisfactory energy performance of the building.