Building Indoor Environmental Quality Research Articles

Occupants’ Interaction With an Occupant Voting System for Thermal and Indoor Air Quality Feedback – Case Studies in Office Spaces

Occupants can provide valuable feedback on the indoor environmental quality of buildings. Research on occupant voting systems (OVS) has demonstrated that apps or electronic devices can act as viable tools for collecting long-term feedback from occupants. However, previous research has only to a limited extent explored occupants’ interaction with OVS and the impact it might have on the reliability of the collected feedback. The present paper presents three case studies on applying a tangible OVS, denoted TiAQ, to collect feedback on thermal and indoor air quality (IAQ) in office spaces. The main objective of the present study was first to explore occupants’ interaction with TiAQ and their motivation. Second, identifying whether feedback collected with TiAQ could represent occupants’ comfort and discomfort with the thermal environment and IAQ. Thirdly, identifying challenges related to occupants’ interaction with TiAQ that might affect the representativeness of collected feedback. The present study was conducted at three office buildings in up to 7 months and demonstrated that TiAQ was suitable for collecting long-term feedback on occupants’ comfort and discomfort with the thermal environment. On average, one vote was cast per day per occupant. Additionally, in one of the office buildings, 60% of occupants reported to have interacted with TiAQ daily or weekly when, e.g., passing the device going to/from the office spaces. Occupants’ expectations of TiAQ and getting “feedback on feedback” need to be further addressed to identify ways to sustain occupants’ long-term use of the device and reduce “ill-willed” interactions.

Assessment of Rising Damp and Indoor Environmental Quality in Buildings after Torrential Rains in Mallorca, Spain

AbstractAs a result of climate change, water-related disasters have increased in the last decade. In the month of October 2018, in the town of Sant Llorenç (Mallorca, Illes Balears, Spain), torrential rains occurred that caused the overflow of the stream that passes through the municipality, causing personal and material damages (including death). In this research, it is intended to develop a characterization of the damage produced in the middle term (seven months after the natural hazard), through the analysis of hygrothermal conditions, humidity in walls, and indoor air quality in seven houses and in one corner shop. The most used or habitable rooms are selected, analyzing a total of twenty-one rooms. The UNE 171330-2-2014 standard is considered for the determination of environmental risks for the occupants’ health. The results obtained show that the users are aware of the need of ventilating the spaces, but, although hygrothermal comfort conditions and indoor air quality are within acceptable ranges, the rising damp highest level is high, since it even exceeds 2 m high in three of the twenty-one rooms assessed. The importance of diagnosing the effects of damage and the vulnerability of buildings in the event of a natural disaster is shown.

Measurement of CO2 concentration for occupancy estimation in educational buildings with energy efficiency purposes

The measurement of CO2 concentration is a relevant indicator for defining the occupation of indoor spaces. The real-time knowledge of occupation of such spaces is relevant both for maintaining indoor air quality standards and for energy efficiency purposes connected with the operation of heating, ventilation, and air-conditioning (HVAC) systems. The exact knowledge of occupation allows for rapid feedback from and the regulation of an HVAC system and the ventilation rate. Interesting applications include educational buildings and other buildings of the civil sector (e.g., shopping centres and hospitals).This paper provides the results of an experimental analysis in different classrooms of a university campus under real operating conditions, in different periods of the year, and with different kinds of activities. The correlation between the CO2 concentration and occupancy profiles of the spaces is then analysed. Some graphical trends of the CO2 concentrations in these indoor spaces are provided to determine the most important variables affecting such concentrations. The basic elements of the mathematical models for estimating the occupation of classrooms in relation to increases in CO2 concentration are also discussed and analysed.

Adaptive lighting comfort in the classrooms of educational building and student hostel rooms

The comfort level of occupants inside a building depends on various indoor environment factors like thermal comfort, indoor air quality, and indoor lighting quality. According to studies done on indoor environment quality of buildings, lighting plays a very critical role in determining the occupants comfort level. A proper indoor lighting is very important especially in the classrooms of an educational building as well as in student hostel rooms as it can be said as a vital element, controlling the psychology and comfort of the students and hence a deciding factor in the teaching-learning process. The lighting intensity and its distribution depends on the location of the interior partition as well as the design strategy of the exterior envelop. So, in order to obtain the most occupant friendly results, the impact of various strategies adopted should be evaluated in the early design period itself. This paper adopts a questionnaire-based field surveys which is done in the classrooms of National Institute of Technology Warangal and also in the hostel rooms of 1.8K Ultra Mega hostel of this institute. The main objective of this study includes. 1) To assess the indoor lighting comfort in the classrooms and hostel rooms of National Institute of Technology Warangal through a questionnaire-based lighting comfort study. 2) To identify preferences of subjects in the classroom environment with respect to lighting comfort and 3) To identify the comfort range of lighting intensity inside the classrooms and hostel rooms. SPSS software is used analyse the reliability of survey responses by finding the P value.

Multi-Season Assessment of Occupant Responses to Manual Shading and Dynamic Glass in a Workplace Environment

The quality and controllability of the building façade can significantly contribute to building indoor environmental quality (IEQ) as well as the building’s energy efficiency. Advanced technologies that support a façade’s dynamic response to climatic changes, such as electrochromic (dynamic) glazing, have emerged as smart systems for IEQ and environmental sustainability. This research summarizes a four-season study of office workers moving from a floor with conventional blinds to work environments equipped with smart dynamic glazing which changes tint in response to weather condition to control daylighting levels. Multiple occupant environmental satisfaction surveys were conducted over one year to investigate differences in environmental and psychological responses to office settings with manual, and often static, facades as compared to offices with dynamic glazing. This research confirms that dynamic glazing significantly affected occupants’ environmental satisfaction—enhancing individuals’ environmental perceptions and psychological health—as compared to manual blinds. It reveals that the occupants in work environments with dynamic glazing reported 21.7% higher productivity gains, 24.8% increased ability to relax, 12.7% improved concentration, 25.3% better moods and 29.4% greater alertness than when they were in offices in the same building with manual shading devices. Also, the dynamic feature of the smart glazing showed a significant contribution to perceived work productivity while enhancing positive emotional responses by an average of 26%.

Comparative study on indoor environmental quality of green office buildings with different levels of energy use intensity

Energy use intensity (EUI) and indoor environmental quality (IEQ) are two key features for evaluating the operating performance of green buildings. However, few researchers have investigated the relationship between the EUI and IEQ in green buildings. In this study, 20 green office buildings from the hot-summer-cold-winter (HSCW) climate zone in China were chosen to investigate their energy use and conduct long-term environmental measurements and occupant satisfaction surveys. Based on over three million sets of environmental data and 1,756 survey samples, IEQ performances (including the thermal comfort, air quality and visual environment) of low- and high-EUI buildings were compared. The results indicate that high-EUI buildings exhibited a significantly better thermal environment, compared to low-EUI buildings. Regarding air quality and visual environment, the two groups did not exhibit huge differences, and their mean levels conformed to the local standard. The subjective surveys led to an inconsistent conclusion: the occupants in high-EUI buildings were less satisfied with the IEQ than those in low-EUI buildings, except for visual environment. The possible underlying reason can be the different levels of environmental control. Furthermore, the detailed relationship between energy use and thermal environment was studied. While green office buildings consume more energy and thus guarantee minimal requirements for thermal comfort, they also waste more energy owing to overcooling or overheating. Finally, an indicator-Environmental Energy Efficiency (EEE)-was introduced and applied to evaluate the comprehensive performance of the energy consumption and IEQ of buildings.

Environmental performance of window systems in patient rooms: a case study in the Belgian context

Hospitals produce high amounts of emissions due to their continuous operation, high flow of people, and intensive HVAC requirements. In order to reduce the environmental footprint of hospitals, it is crucial to improve energy performance while still maintaining a comfortable indoor environment for the occupants. Also to avoid high environmental burdens, it is important to understand the impact of building material selection from the full life cycle perspective. Window systems influence the energy loads and comfort in buildings and provide access to daylight and views. Therefore, windows contribute significantly to the energy consumption and indoor environmental quality of buildings and impact the well-being of occupants. The aim of this study is to determine the influence of various window system design configurations on the environmental performance of patient rooms in Belgium through life cycle assessment (LCA). The method is innovative as it combines dynamic energy simulations and daylight analysis and integrates these in the LCA study of the window systems. The influence of several components is investigated, such as the choice of glazing and shading system. The results are analysed and compared in terms of energy cost for heating, cooling, and lighting, daylighting performance and life cycle environmental impacts. A typical patient room from a hospital design in Belgium is used as a case study. Based on comparative analysis, the paper discusses potential window system design configurations that allow for energy efficient, daylit and environmentally-friendly patient rooms.

Changes in EEG signals during the cognitive activity at varying air temperature and relative humidity.

In this study, we examined changes in EEG signals during the cognitive activity at different air temperatures and relative humidities (RH). Thirty-two healthy young people acclimatized to the subtropical climate of Changsha, China, were recruited as subjects. They experienced four air temperature levels (26, 30, 33, and 37 °C) and two relative humidity levels (50 and 70%) in a climate chamber. During 175 min-long exposures to each thermal condition, they performed cognitive tasks and their EEG signals were measured. Relative humidity of 70% and increased temperature at this relative humidity significantly increased the relative power of δ-band and significantly decreased relative power of θ-band, α-band, and β-band. This may suggest that subjects were more sleepy but less drowsy, and it was more difficult for them to think clearly. At the same time, subjective evaluations indicated that they could be less alert and it was harder for them to think. However, no changes in performance of tasks measuring cognitive abilities were observed. It remains therefore unclear whether EEG can be a credible marker of changes in cognitive activity as a result of changes in indoor environmental quality in buildings and the future experiments should closely examine this issue.

The appearance and luminous properties of lime and gypsum pastes: A comparative analysis of different methods of measurement

Lighting, both natural and electric, is one of the key points in the indoor environmental quality in buildings and it is directly related to their energy efficiency and indoor comfort conditions. Since final lighting conditions depend on the luminous reflectance properties of interior surfaces, an accurate characterization of this property is essential in evaluating its effect on the aforementioned lighting conditions. However, there is scarce research into the effect of this type of binder as well as roughness and colour on the indoor luminous conditions. The aim of this research is to evaluate the influence of the luminous reflectance and texture of the finishing layers of plasters and renders based on lime and gypsum pastes with three different colours (non-coloured, ochre and red) and two types of finishing (smooth and rough) under the luminous conditions. The results show that lime paste samples showed a higher reflectance than those of gypsum. In both cases, the performance is diffused with an optimal reflectance when light incidences are between 45° and 75°.Furthermore, four different methods for measuring the reflectance were used to find a practical way of assessing the daylighting potential. Laboratory measurements under artificial lighting were compared with controlled laboratory measurements with natural lighting as well as on site evaluations under real clear sky conditions. While with lime samples clear correlations were found, differences up to 13% were found in gypsum pastes, possibly due to their glossy finish.

Monitored Indoor Environmental Quality of a Mass Timber Office Building: A Case Study

A broad range of building performance monitoring, sampling, and evaluation was conducted periodically after construction and spanning more than a year, for an occupied office building constructed using mass timber elements such as cross-laminated timber (CLT) floor and roof panels, as well as glue-laminated timber (GLT) beams and columns. This case study contributes research on monitoring indoor environmental quality in buildings, describing one of the few studies of an occupied mass timber building, and analyzing data in three areas that impact occupant experience: indoor air quality, bacterial community composition, and floor vibration. As a whole, the building was found to perform well. Volatile organic compounds (VOCs), including formaldehyde, were analyzed using multiple methods. Formaldehyde was found to be present in the building, though levels were below most recommended exposure limits. The source of formaldehyde was not able to be identified in this study. The richness of the bacterial community was affected by the height of sampling with respect to the floor, and richness and composition was affected by the location within the building. Floor vibration was observed to be below recognized human comfort thresholds.

Numerical Simulations and Empirical Data for the Evaluation of Daylight Factors in Existing Buildings in Sweden

Point Daylight Factor (DFP) has been used for daylighting design in Sweden for more than 40 years. Progressive densification of urban environments, in combination with stricter regulations on energy performance and indoor environmental quality of buildings, creates complex daylight design challenges that cannot be adequately solved with DFP. To support a development of the current and future daylight indicators in the Swedish context, the authors have developed a comprehensive methodology for the evaluation of daylight levels in existing buildings. The methodology comprises sample buildings of various use and their digital replicas in 3D, detailed numerical simulations and correlations of diverse DF metrics in existing buildings, a field investigation on residents’ satisfaction with available daylight levels in their homes, and a comparison between the numerical and experimental data. The study was deliberately limited to the evaluation of DF metrics for their intuitive understanding and easy evaluation in real design projects. The sample buildings represent typical architectural styles and building technologies between 1887 and 2013 in Gothenburg and include eight residential buildings, two office buildings, two schools, two student apartment buildings, and two hospitals. Although the simulated DFP is 1.4% on average, i.e., above the required 1%, large variations have been found between the studied 1200 rooms. The empirical data generally support the findings from the numerical simulations, but also bring unique insights in the residences’ preferences for rooms with good daylight. The most remarkable result is related to kitchens, typically the spaces with the lowest DF values, based on simulations, while the residents wish them to be the spaces with the most daylight. Finally, the work introduces a new DF metric, denoted DFW, which allows daylighting design in early stages when only limited data on the building shape and windows’ arrangement are available.

Dynamic behaviour of bio-based and recycled materials for indoor environmental comfort

Abstract UK construction industry contributes 120 Mt of waste every year. Bio-based building materials may be a solution for this problem, as they combine re-use and recycling abilities together with hygroscopic characteristics, leading to buildings energy savings. For the first time, the dynamic response to hygrothermal changes of bio-based materials is examined in terms of Moisture Buffering Value (MBV), dry/wet thermal conductivity, microstructure, density and latent heat through daily cycles. It is shown that MBV is a useful tool for characterisation but needs to be combined with the shape of the change in mass of the final hygrothermal cycle. Mastering this is required to obtain significant improved indoor environment quality in buildings. Ten samples of bio-based insulation materials and one thermoplastic recycled polymer were analysed (wool, hemp, saw mill residue, wood, straw, cork and polyethylene terephthalate). Saw and wool are the most promising, as materials exhibit dynamic response to hygrothermal changes. Only half the amount of samples revealed equivalent efficient moisture transfer to be able to desorb the adsorbed quantity of water. Latent heat of vaporisation and condensation tests led to the conclusion that samples of wool and saw mill residue can qualify as bio-based materials for ‘green’ panels.

Thermo-chromic glazing in buildings: a novel methodological framework for a multi-objective performance evaluation

Transparent adaptive façade components can improve the energy performance and the indoor environmental quality of buildings. Nevertheless, their utilization is not widespread, due also to the lack of a robust methodology to comprehensively evaluate their potentialities and find out their most suitable applications. The present paper introduces a novel methodology to characterize the behavior of a transparent adaptive façade component, a thermo-chromic glazing, and predict its effects, through numerical simulations, on energy performance and visual comfort aspects. An experimental characterization on the thermo-chromic glazing was performed to determine its optical properties at the variation of its surface temperature. The component was found to be able to switch its visible transmittance between 0.71 and 0.13, and its solar transmittance between 0.65 and 0.28. The experimental results were used to feed the numerical model created on purpose to describe the adaptive behavior of the component. Finally, a numerical simulation campaign was performed to assess the effects of the thermo-chromic glazing on energy and visual comfort aspects of an enclosed office located in Turin. It was found that the thermo-chromic glazing reduced the overall energy performance compared to a static selective glazing, but it allows improving the visual comfort conditions within the space considered.

PERFORMANCE OF A GREEN BUILDING'S INDOOR ENVIRONMENTAL QUALITY ON BUILDING OCCUPANTS IN SOUTH AFRICA

Indoor environmental quality (IEQ) is important to the health, comfort, and well-being of building occupants. Unsatisfactory IEQ is associated with a number of phenomena, most notably, sick building syndrome (SBS), building-related illnesses (BRIs), and multiple chemical sensitivity (MCS), which have major negative effects on productivity. However, green building investors (owners) are not only concerned about reducing the negative impact of their buildings on the environment, but also about the potentially negative impact green buildings can have on their employees' productivity. This research sets out to address, through a questionnaire survey in South Africa, what constitutes the determinants of green building occupants' satisfaction with the IEQ elements of a green building and the health implications of a building's IEQ on the building occupants. Data analysis (involving a one-sample t-test) reveals some interesting findings in regard to what constitutes the determinants of green building occupants' satisfaction with the IEQ elements and the health implications of the IEQ elements of a five-star green rated building in South Africa. Findings from the survey revealed that the occupants of the building were not satisfied with the green building's IEQ, most especially the ineffectiveness of blocking natural and artificial lighting. Also, it was revealed that the IEQ with particular reference to the noise level and ventilation of the space has some serious health implications for the building occupants. The occupants' evaluation revealed that the major health issues from which they suffer include fatigue, headache, common cold, coughing, and influenza, and these affect their productivity and performance. Since building occupants are a rich source of information about IEQ assessment and its effect on productivity, the study can be used to assess the performance of green buildings, identify areas needing improvement, and provide useful feedback to designers and operators about specific aspects of green building design features and operating strategies that need improvement. This study adds to the body of knowledge on green buildings' IEQ performance.

Utilisation of building information modelling for indoor environmental quality assessment – A review

The indoor environmental quality (IEQ) is considered as a social aspect of sustainability that concerns on health, safety and well-being of building occupants. The satisfaction of occupants in the buildings is affected by acoustic, thermal, lighting and ventilation and has been corresponding to the self-estimated workers job performance in the workspace. The poor indoor environmental quality in building has resulted to health problems such as asthma and cancers and this having an effect in frequency of absenteeism and intention to quite job. Therefore, occupant satisfaction is an important factor in the design, operation, and management of buildings. This study reviews the extent to which relevant literature on IEQ has been carried out and the utilisation of Building Information Modelling (BIM) for the IEQ assessment. Reviewed works shows that many works have been carried out on indoor environmental quality of buildings and other aspect of sustainability such as environmental and economic sustainability. However, despite an increased interest in GreenBIM, it is surprising that little empirical research has been conducted on the topic. Most of the studies are directed towards the environmental benefits of sustainability such as energy consumption, carbon dioxide emission, and waste reduction. This study aims to identify areas that are yet to be considered and provides information on interventions that could be used to improve the health and wellbeing of occupants of the building is a compliment to previous studies that are on the other components of sustainability.

Impact of IPPC Scenarios on indoor environment quality of historic buildings

Ensuring proper indoor environment quality in buildings with historic value or buildings located in historic centres of cities is not an easy task. These buildings are frequently listed in historic preservation lists; thus, the amount of possible refurbishment methods is significantly limited due to increased protection. This article deals with comprehensive analysis of internal microclimate of a multi-purpose building located in the historic centre of Prague during summer period. Possible refurbishment methods permitted by the National Heritage Institute are analysed and compared using building energy performance simulation tool BSim in order to achieve proper working conditions in offices in the building. Structural and technical modifications are proposed in order to optimize the amount of solar heat gains leading to reduction of overheating and increase of energy efficiency. Furthermore, two global warming projections from the Fourth Assessment Report of Intergovernmental Panel on Climate Change are applied to the current weather data to examine the impact of the global climate change on the building. As expected, the cooling demand increases with the climate change scenarios presenting more difficult challenges to maintain the indoor environment quality within the limitations given by the legislation.

Indoor Fungal Growth on Variable Antifungal at Different Wall Finishing on Plasterboard

Various health complaints often been attributed to pollution and the poor quality of the indoor air. If there is good practice in building design, construction, and maintenance, the structures should remain dry. However, when there is moisture damage, the materials may be in contact with water for prolonged times, which inevitably leads to microbial growth or even total deterioration of the building material. Antimicrobial coating is designed to generate a surface that is easy to clean and can also incorporate active agents, commonly called antifungal, that prevent microbial colonization, the subsequent growth and bio-deterioration of the substrate. This paper presents the sustainable treatment for indoor environment quality in buildings by examining the application of potassium sorbate, zinc salicylate, and calcium benzoate that used as food industry preservatives as indoor antimicrobial agents. Four types of wall finishing used on plasterboard substrate: acrylic paint, glycerol based-paint, thin wallpaper, and thick wallpaper. The result indicated that potassium sorbate is the best bio compound to react as antifungal agent to prohibit the growth of indoor fungi. All the antifungal shows difference level of their effectiveness from each other. Only 40% of fungi were able to grow on thin wallpaper by using potassium sorbate as antifungal agent.

Determination of optimal plaster thickness for moisture buffering of indoor air

The relative humidity of indoor air influences the health and wellbeing of building occupants and the integrity of the building fabric. One potential solution for regulating relative humidity is provided by the plaster used for finishing internal spaces if it has the ability to passively buffer moisture through adsorption and desorption of vapour. During the adsorption and desorption, the water vapour will only penetrate to a certain depth of the plaster. Therefore, it is important to know the minimum thickness of plaster required for the maximum buffering effect. Uniquely, this paper presents a method for determining the optimal thickness from experimental measurements on specimens of varying thickness. In this paper it is demonstrated through a novel method, that there is a thickness of material beyond which there is no increase in moisture buffering capacity. Below the optimal thickness moisture sorption increases linearly as a product of the density and specific moisture capacity. Significantly, existing numerical methods were found to overestimate the performance when compared to empirical measurements. The expected impact of this work is the increased knowledge of surrounding material performance and use, that will ultimately improve the indoor environment quality of buildings and occupant health.

Multitrait-multimethod analysis of subjective and objective methods of indoor environmental quality assessment in buildings

Indoor environmental quality (IEQ) refers to the condition of a building’s internal environment that is related to the occupants’ health, comfort, and wellbeing. The assessment and improvement of IEQ in buildings are based on either subjective or objective assessment or the use of both measures, and in recent times, have been attracting attention due to its role in contributing to green building and sustainable environment. This study is aimed at evaluating and analysing the validity of the IEQ parameter traits as assessed using subjective and objective measures. The convergent and discriminant validity of the measured parameter traits were tested by analysing a multitrait–multimethod (MTMM) matrix using confirmatory factor analysis (CFA). The results indicated that there is no convergent validity in the IEQ parameter traits as assessed using subjective and objective methods. However, discriminant validity of the measured parameter traits was adequately supported. This clearly shows that as much as IEQ parameter traits measured through objective physical measurement and subjective occupant survey define the same concept, they cannot be taken to represent a single and same unit of measurement.

The impact of IEQ on occupants’ satisfaction in Malaysian buildings

This paper focuses on the importance of occupant satisfaction with indoor environmental quality in buildings as well as the effect of indoor environmental quality towards occupants’ satisfaction. This research applied post-occupancy evaluation as a method to indicate the building occupants’ needs, their satisfaction and comfort level. The research is based on a case study approach whereby a questionnaire survey was conducted among 25 organizations involved in managing office buildings. A total of 115 questionnaires were returned for evaluation of occupants’ overall satisfaction from aspects of indoor environmental quality in these buildings and to determine the occupants’ satisfaction level within these buildings. The findings revealed that indoor environment factors that could contribute to occupants’ satisfaction consists of lighting, air quality and aesthetic perception. These classifications were made based on the factor analysis done with 22 attributes of the indoor environment. The majority of occupants are satisfied with their health conditions and do not face any serious health problems. However, occupants highlighted that some environmental conditions, health effects, air movement, ventilation and air freshness are important criteria for their satisfaction and comfort. This study provides insights into how occupants perceive their indoor environment and comfort, and identify problems that could arise in buildings.