Indoor Environmental Quality Factors Research Articles

Monitoring and Assessment of Indoor Environmental Conditions after the Implementation of COVID-19-Based Ventilation Strategies in an Educational Building in Southern Spain.

Since students and teachers spend much of their time in educational buildings, it is critical to provide good levels of indoor environmental quality (IEQ). The current COVID-19 pandemic has shown that maintaining a good indoor air quality level is an effective measure to control the transmission of the SARS-CoV-2 virus. This study used sensors to monitor key IEQ factors and assess several natural ventilation scenarios in a classroom of the University of Granada. Subsequently, the IEQ factors (temperature, relative humidity, CO2 concentration, acoustic environment, and air velocity) were evaluated for the selected ventilation scenarios in the occupied classroom, and the field monitoring was carried out in two different assessment periods, winter and summer. The obtained results show that the CO2 concentration levels were well below the recommended limits. However, the maintenance of the recommended thermal and acoustic IEQ factors was significantly affected by the natural ventilation strategies (temperature and relative humidity values were very close to the outside values, and the background sound pressure level was over 35 dBA during the entire assessment). The proper measurements and careful selection of the appropriate ventilation scenarios become of utmost importance to ensure that the ventilation rates required by the health authorities are achieved.

Condition assessment model of building indoor environment: a case study on educational buildings

PurposeThe purpose of this study is to develop a condition assessment (CA) model for a building's indoor 21 environments and to improve the building's asset management process.Design/methodology/approachThe methodology is based on dividing the building into spaces, which are the principal evaluated elements based on the building's indoor environmental quality (IEQ). An evaluation scheme was prepared for the identified factors and the analytical hierarchy process (AHP) technique was used to calculate the relative weight of each space inside the building as well as the contribution of each IEQ factors (IEQFs) in the overall environmental condition of each space inside the building. The multi-attribute utility theory (MAUT) was then applied to assess the environmental conditions of the building as a whole and its spaces. An educational building in Canada was evaluated using the developed model.FindingsEach space type was found to have its own IEQFs weights, which confirms the hypothesis that the importance and allocation of each IEQF are dependent on the function and tasks carried out in each space. A similar indoor environmental assessment score was calculated using the developed model and the building CA conducted by the facility management team; “89%” was calculated, using K-mean clustering, for the physical and environmental conditions.Originality/valueIEQ affects occupants' assessment of their quality of life (QOL). Despite the existence of IEQ evaluation models that correlate the building's IEQ and the occupants' perceived indoor assessments, some limitations have led to the necessity of developing a comprehensive model that integrates all factors and their sub-criteria in an assessment scheme that converts all the indoor environmental factors into objective metrics.

The impact of home office setup due to COVID-19 pandemic on IT professionals′ physical health: a systematic review

Abstract Introduction The COVID-19 pandemic represented a great reset in terms of how we work; it affected all organizational levels and brought up unexpected challenges, forcing a lot of workers to shift into working from home. A home office may not be suitable for IT professionals as it is not usually designed ergonomically for long-term use. This study aimed to explore the effects of the COVID-19 pandemic on IT professionals’ physical health who hypothetically deal with non-ergonomic workstations at home and with modified workloads. Material and method The research was conducted based on PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyzes) methodology. The scientific material was selected through a search in PubMed, Scopus, Clarivate Analytics, and Google Scholar databases; the eligible studies were published in 2020 and 2021, involved IT professionals who shifted to home office due to the COVID-19 pandemic and analysed the physical health issues related to these changes. Results Physical health outcomes as neck pain and other musculoskeletal complaints, along with increased stress and anxiety, as mental issues, were reported in most of the participants interviewed in the selected studies; the musculoskeletal complaints were strongly influenced by the unexpected changes that came along with working from home in terms of workload and workstations. On the other hand, having a room dedicated to professional activities, an ergonomic workstation, knowing how to adjust the workstation, and increased satisfaction with indoor environmental quality factors in the workspaces were associated with a lower chance of developing new health problems during this period. Conclusion The present study confirms that in the case of IT professionals there is a strong association between working from home, poor ergonomic workstations and high prevalence of musculoskeletal complaints, and, especially, an increased occurrence of neck pain.

Factors Affecting Occupants’ Satisfaction in Governmental Buildings: The Case of the Kingdom of Bahrain

Satisfaction is a very important factor in improving productivity and performance in the work environment. This study aims to investigate the levels of occupants’ satisfaction with the indoor environmental quality (IEQ) in the governmental buildings in the Kingdom of Bahrain and to investigate the impact of occupants’ demographics and building attributes (non-IEQ factors) on these levels. For these purposes, the study used a questionnaire that has 17 indoor environmental quality (IEQ) factors in addition to a group of non-IEQ factors. The questionnaire was distributed by hand or using email to 279 employees in the Bahraini governmental sector. The findings of the study revealed that occupants in the Bahraini governmental buildings are not strongly satisfied with IEQ factors, especially with sound privacy, followed by visual privacy and amount of space, and then noise levels. The findings also showed that for most IEQ factors, men are more satisfied than women are, those who work in enclosed private offices are more satisfied than those who work in open-plan offices, and those who have central air-conditioning at their workplace are more than those who have a wall-mounted air conditioner. The impact of age, nature of work, duration of working in the current building and at the current workstation, weekly working hours, and proximity to the window were also investigated. Accordingly, a group of recommendations was suggested aiming to improve the levels of occupants’ satisfaction.

Time spent in the office and workers’ productivity, comfort and health: A perception study

The importance of the office environment to the comfort, productivity and health of workers cannot be overstated. While extant literature has shown that the physical environment of an office has a significant influence on how workers' perform their duties and on their comfort and health, few studies have explored the part played by the length of time they spend in the office. Using our dataset of 5149 workers from across the globe, we investigated the influence of time spent in the office building and at workstations on the relationship between Indoor Environment Quality (IEQ) and workers' productivity, comfort and health. An analysis of variance (ANOVA), Pearson's correlation and multiple regression analyses were employed. Our findings showed that while those who spent less time at work were less influenced by IEQ factors, noise and air quality were predominant in predicting how those who spent more time at work felt about their productivity, comfort and health. Specifically, a relationship did not exist between all of the IEQ factors and their perception of health for workers who spent less time in the office building. Also, the time spent in the office had a greater influence on the relationship between IEQ and workers' comfort than on their productivity and health. Our findings are useful for measures that ensure office workers achieve required work-related tasks under the appropriate working conditions. They give essential insights into the appropriate length of time workers should spend in the office.

Effect of Thermal, Acoustic and Air Quality Perception Interactions on the Comfort and Satisfaction of People in Office Buildings

Current research on human comfort has identified a gap in the investigation of multi-domain perception interactions. There is a lack of understanding the interrelationships of different physio-socio-psychological factors and the manifestation of their contextual interactions into cross-modal comfort perception. In that direction, this study used data from a post occupancy evaluation survey (n = 26), two longitudinal comfort studies (n = 1079 and n = 52) and concurrent measurements of indoor environmental quality factors (one building) to assess the effect of thermal, acoustic and air quality perception interactions on comfort and satisfaction of occupants in three mixed-mode university office buildings. The study concluded that thermal sensation (TSV) is associated with both air quality (ASV) and noise perception (NSV). The crossed effect of the interaction of air quality and noise perception on thermal sensation was not evident. The key finding was the significant correlation of operative temperature (Top) with TSV as expected, but also with noise perception and overall acoustic comfort. Regarding the crossed main effects on thermal sensation, a significant effect was found for the interactions of (1) Top and (2) sound pressure levels (SPL30) with air quality perception respectively. Most importantly, this study has highlighted the importance of air quality perception in achieving occupants’ comfort and satisfaction with office space.

Ten questions concerning occupant health in buildings during normal operations and extreme events including the COVID-19 pandemic

Even before the COVID-19 pandemic, people spent on average around 90% of their time indoors. Now more than ever, with work-from-home orders in place, it is crucial that we radically rethink the design and operation of buildings. Indoor Environmental Quality (IEQ) directly affects the comfort and well-being of occupants. When IEQ is compromised, occupants are at increased risk for many diseases that are exacerbated by both social and economic forces. In the U.S. alone, the annual cost attributed to sick building syndrome in commercial workplaces is estimated to be between $10 billion to $70 billion. It is imperative to understand how parameters that drive IEQ can be designed properly and how buildings can be operated to provide ideal IEQ to safeguard health. While IEQ is a fertile area of scholarship, there is a pressing need for a systematic understanding of how IEQ factors impact occupant health. During extreme events, such as a global pandemic, designers, facility managers, and occupants need pragmatic guidance on reducing health risks in buildings. This paper answers ten questions that explore the effects of buildings on the health of occupants. The study establishes a foundation for future work and provides insights for new research directions and discoveries.

A study on changes in occupants' thermal sensation owing to CO₂ concentration using PMV and TSV

Indoor environmental quality (IEQ) factors must be controlled appropriately to ensure the health and work efficiency of building occupants. To accurately evaluate IEQ factors, the correlations between factors must be considered, rather than classifying each factor independently. CO₂ concentration, which indicate indoor air quality, are related to respiration. Given that CO₂ concentration influence occupants' thermal sensation, it is difficult to ensure thermal comfort in addition to indoor air quality, solely by performing thermal environment control in a space that does not have suitable ventilation. This study used the Discrepancy between TSV and PMV (DV) in each CO₂ concentration section to analyze the effect of CO₂ concentration on thermal comfort evaluations in university library. Based on this analysis, this study proposes a novel air conditioning control method that considers the indoor air quality and thermal environment together. This study also used simulations to analyze the indoor thermal environment and energy consumption that occurred as a result of the ventilation control strategy when the novel control method was applied. The results showed that occupants' thermal sensation became more sensitive to heat as the CO₂ concentration increased, and it is energy efficient to regulate occupants’ thermal sensation by introducing suitable ventilation such as the Demand Controlled Ventilation (DCV) control method when applying novel control method during intermediate seasons.

Higher education students’ indoor environmental quality satisfaction benchmark

ABSTRACT Post-occupancy evaluation is a well-known research method documenting occupants’ satisfaction with indoor environmental quality (IEQ) factors. Despite potentially significant roles of gender differences in IEQ satisfaction, it has not always been acknowledged by researchers and findings are debated. Through a self-administered questionnaire over nine years, students (n = 3140) in 11 different higher education classroom buildings in Minnesota, USA rated their satisfaction with 23 IEQ factors. They were most satisfied with overall cleaning and maintenance followed by overall indoor air quality and amount of electric lighting. Students were least satisfied with access to electric outlets followed by daylighting IEQ factors. Mann–Whitney U tests showed that female students were statistically less satisfied with overall thermal conditions and temperature, while male students were statistically less satisfied with daylighting, electric lighting, and view conditions. Subsequent logistic regression analyses indicated the most significant impact of amount of electric lighting. The results imply that once students were dissatisfied with amount of electric lighting, they were more likely to be dissatisfied with the classroom. Despite the significant impacts of all IEQ factors, the different degree of the likelihoods indicates that some IEQ factors may impact classroom satisfaction more than other IEQ factors as indicated by this benchmark study.

A Review of Balcony Impacts on the Indoor Environmental Quality of Dwellings

Balconies are an ancient architectural archetype that are being increasingly considered in multi-family buildings of high-density cities. This paper aims to provide a comprehensive review of the impacts of balcony types on the indoor environmental quality (IEQ) and energy consumption of dwellings. Of the reviewed studies, 69% were published during the last decade, making it evident that awareness of the positive impact of balcony spaces is continuously increasing. The literature review allowed us to identify three balcony spaces according to their morphology and their boundary system: open balcony (OB), glazed balcony (GB), and eliminate balcony (EB). It was concluded that these balcony types produce relevant impacts in four factors that contribute to the indoor environmental quality: thermal comfort, indoor air quality, visual comfort, and acoustic comfort. Practical design recommendations and constraints were provided according to distinct climatic conditions and building technologies. This review also explored the assessment methodologies used for the optimization of the balconies on the design process. The literature highlighted the lack of a comprehensive study about the impact of balconies in mild and Mediterranean climates, as well as the knowledge limitations concerning the balance between the impacts on IEQ factors.

Indoor environmental quality factors that matter to workplace occupants: an 11-year-benchmark study

ABSTRACT Post-occupancy evaluations (POE) have been often used to study user satisfaction with office environments. More recently, POEs have been recognized for documenting occupant well-being and responses to 26 indoor environmental quality (IEQ) factors that incorporate sustainable design guidelines such as thermal, lighting, and acoustic conditions. The Sustainable Post-Occupancy Evaluation Surveys (SPOES) have measured occupants’ (n = 2836) satisfaction with IEQ factors for 11 years. This paper presents findings from this 11-year-benchmark study. It suggests a lower satisfaction rating for adjustability than other IEQ factors. Based on further logistic regression analyses of the IEQ factors, occupants tended to be dissatisfied with their primary workspace when they were dissatisfied with acoustic conditions, furnishings, and privacy. The results imply that improving acoustic and privacy conditions, especially, would bring the most significant impact on the positive experience in built environments, whereas improving thermal conditions would impact relatively less significant on the positive experience. Acknowledging how differently each IEQ factor can affect building occupants’ satisfaction and perception is important for determining benchmarks that support occupants’ health and well-being in the workplace environment, where they spend much of their time.

Indoor Environmental Quality (IEQ) Analysis of a Two-Sided Windcatcher Integrated with Anti-Short-Circuit Device for Low Wind Conditions

Windcatchers are considered as promising passive ventilation and cooling strategy, but the ventilation performance of this system is still of concern in areas with low speed and unpredictable winds. The air short circuiting in windcatchers can reduce its ventilation performance and ability to introduce clean air and remove stale air. The current work aimed to evaluate the indoor environmental quality (IEQ) performance of a two-sided windcatcher fitted with an anti-short-circuit device (ASCD) for improving its performance in low wind speed conditions. Computational Fluid Dynamics (CFD) simulations were performed for different ASCD configurations. The CFD method was verified using grid-sensitivity analysis and validated by comparing the simulation results with wind tunnel data. The results indicated that the average difference between CFD results and previous experimentation was below 10%, therefore indicating good agreement. Building on the findings of the previous research, the study focused on evaluating the impact of the length of ASCD on the achieved fresh air supply rates and air change rate. The length of the ASCD was varied between 5 cm to 50 cm, while the angle was maintained at 80°. The shorter ASCD was still able to minimize the fresh supply airflow short-circuiting to the exhaust stream, and at the same time, it would also require a smaller ceiling space for installation and lower material cost. Hence, the 15 cm ASCD with 80° angle was selected for further analysis in this study. Then, consideration of low wind speed and various directions were studied to evaluate the ventilation performance of windcatcher with ASCD. The study simulated wind speeds between 0.5–2 m/s and two wind directions. Based on the assessment of IEQ factors, including mean age of air and percentage of dead zone, a 0° incident angle demonstrated slightly better results. The achieved fresh air supply rates ranged between 180 L/s to 890 L/s in 45° wind angle, while, for 0°, these values were from 160 L/s to 642 L/s. Likewise, the range of air change rates (ACH) was from 8 ACH to 32 ACH in 0° wind angle and increased to 9 ACH and then to 45 ACH in 45° wind angle.

Towards a holistic approach for assessing the impact of IEQ on satisfaction, health, and productivity

ABSTRACT While there is broad evidence of the impact of tangible factors (i.e. room temperature, indoor air quality) on work well-being and productivity, the objective measurement of intangible factors (i.e. ergonomics and privacy) is still an under-researched subject. A holistic approach to indoor environmental quality (IEQ) has been developed in this study by combining the research dimensions of IEQ factors (tangible vs. intangible), outcome (workplace satisfaction, health, productivity), method (subjective vs. objective assessment) and impact (direct vs. indirect effects), and it has been tested in a laboratory (n = 180). The main findings are that (i) workplace satisfaction, health and productivity are more strongly affected by intangible factors than by tangible ones, (ii) impaired privacy leads to sick building symptoms and less creativity, (iii) negative self-assessment impairs objective performance in the form of a self-fulfilling prophecy, while (iv) personality traits correlate differently with ergonomics and privacy. Hence, a holistic IEQ approach that also considers interrelations between the research dimensions is beneficial for creating supportive workplace designs.

Effect of thermal comfort on occupant productivity in office buildings: Response surface analysis

Thermal environment is one of the main factors that influence occupants' comfort and their productivity in office buildings. There is ample research that outlines this relationship between thermal comfort and occupant productivity. However, there is a lack of literature that presents mathematical relationship between them. This paper presents a research experimental study that investigates effects of indoor environmental quality factors on thermal comfort and occupant productivity. This study was conducted by collecting indoor environmental quality parameters using sensors and online survey for twelve months. Data analysis was done using Response Surface Analysis to outline any mathematical relationship between indoor environmental quality and occupant productivity. The outlined relationships confirmed dependencies of occupant thermal comfort and productivity on various indoor environmental factors. These dependencies include the effect of CO2 concentration, VOC concentration. These relationships were analysed to rank nine indoor environmental parameters as per the degree of effect on occupant thermal comfort and productivity. These findings would help design professionals to design better office design that would improve occupants’ comfort and their productivity. Study results have different implications for professionals working in design, construction and operation of office buildings. It is recommended that design guidelines for office buildings should consider occupant productivity and incorporate recommended range for indoor environmental quality parameters in respective categories and criteria.

The Impact of Indoor Environmental Quality of Green Buildings on Occupants' Health and Satisfaction: A systematic review

Introduction: The main benefits of green buildings for energy and water conservation have been investigated and well recognized in previous studies. However, indoor environmental quality (IEQ) and human health benefits of green buildings have not been examined comprehensively. This study aimed to conduct a systematic review over the current status of green and non- green buildings on their occupants’ health and satisfaction. Method: A systematic search was conducted throughout the following databases: Science Direct, Google Scholar, and Springer. We reviewed 690 articles that examined the relationship between buildings and health. In total, after excluding the irrelevant titles and non-­English articles, 40 papers were included in the final analysis. Articles that evaluated IEQ factors and occupants’ health through surveys from 2005 to 2018 years were selected for investigation. Results: The most important result of this study was identification of important factors in IEQ, including building design, aesthetics, and ergonomics, which have been less evaluated in previous research. Contrary to our assumption, the results of several studies indicated a further decline in IEQ parameters in buildings with Leadership in Energy and Environmental Design (LEED, USA) and Building Research Establishment Environmental Assessment Method (BREEAM, Europe) certification. However, performance improvements were reported in green buildings located in Asia (especially Singapore and Taiwan). Conclusion: According to this systematic review, we cannot claim that occupants of the green buildings enjoy higher IEQ, satisfaction, or health, compared with the occupants of non-green buildings.

Prevalence of psychological distress and its association with perceived indoor environmental quality and workplace factors in under and aboveground workplaces

The development of underground spaces serves a range of common urban functions, including workspaces. However, underground workplaces, work-related factors and the indoor environmental quality (IEQ) parameters within them may negatively affect worker's mental health. This study assessed the prevalence of psychological distress with repeated measures over time in aboveground and underground workspaces, and assessed the association between perceived IEQ parameters and work-related factors with psychological distress. A total of 329 workers in similar aboveground and underground workspaces were followed-up in three assessments over 12 months in Singapore. Psychological distress was assessed using the 12-item General Health Questionnaire (GHQ-12) and defined as a GHQ-12 score ≥2. Perceived IEQ (air quality, temperature, noise, light) in the workplace were collected using the OFFICAIR questionnaire. We used generalised estimating equation models to assess the association between working underground, perceived IEQ, and work-related factors with psychological distress. The overall prevalence of psychological distress was 21.9%, 26.1% and 21.9%, at baseline, 3- and 12-months follow-up, respectively. The fully-adjusted multivariable analysis did not show any association between working underground and psychological distress, however, perceived IEQ parameters and longer working hours were significantly associated with psychological distress. Regardless of working in under or aboveground workplaces, perceived IEQ was associated with psychological distress. Future studies are needed in order to examine the relationship between objective measures of IEQ and psychological distress and the impact of healthy building policies and improved IEQ on psychological distress.

Workplace indoor environmental quality and asthma-related outcomes in healthcare workers.

Asthma-related health outcomes are known to be associated with indoor moisture and renovations. The objective of this study was to estimate the frequency of these indoor environmental quality (IEQ) factors in healthcare facilities and their association with asthma-related outcomes among workers. New York City healthcare workers (n = 2030) were surveyed regarding asthma-related symptoms, and moisture and renovation factors at work and at home during the last 12 months. Questions for workplace moisture addressed water damage (WD), mold growth (MG), and mold odor (MO), while for renovations they addressed painting (P), floor renovations (FR), and wall renovations (WR). Regression models were fit to examine associations between work and home IEQ factors and multiple asthma-related outcomes. Reports of any moisture (n = 728, 36%) and renovations (n = 1412, 70%) at work were common. Workplace risk factors for asthma-related outcomes included the moisture categories of WD by itself, WD with MO (without MG), and WD with MG and MO, and the renovation category with the three factors P, FR, and WR. Reports of home IEQ factors were less frequent and less likely to be associated with health outcomes. Data analyses suggested that MG and/or MO at work and at home had a synergistic effect on the additive scale with a symptom-based algorithm for bronchial hyperresponsiveness. The current study determined that moisture and renovation factors are common in healthcare facilities, potentially putting workers at risk for asthma-related outcomes. More research is needed to confirm these results, especially prospective studies.

Interactions and comprehensive effect of indoor environmental quality factors on occupant satisfaction

In this study, eight subjects were exposed in a simulated office to 31 combinations of indoor environmental conditions, assigned by orthogonal design and uniform design. Conditions comprised variations of Predicted Mean Vote (PMV), illuminance, sound pressure and CO2 concentration (independent of a consistent ventilation rate) as indicators of thermal, lighting, acoustic and indoor air quality. Participant satisfaction with each of the four factors and with overall environmental conditions were measured with a questionnaire. Multiple interactions were detected with a partial correlation analysis and regression analysis. Results showed an adjusted effect of illuminance on perceived acoustic environment, a significant effect of the thermal environment on indoor air quality satisfaction, and a slight effect of sound pressure on indoor air quality satisfaction. Linear and geometric mean regression models were investigated for predicting overall satisfaction from the factor satisfaction scores. For the linear model, it was determined that multicollinearity among factor satisfaction levels may result in non-significant and biased estimated coefficients. The geometric mean regression model provides better prediction accuracy than the linear regression model with fewer coefficients, and accounts for the finding that the lowest satisfaction level with any environmental factor appears to drive overall satisfaction.

Optimizing Indoor Environmental Quality in hot arid climates

Indoor Environmental Quality (IEQ) is a key indicator of the quality of the built environment and the health of its occupants. The purpose of this study is to investigate a range of IEQ parameters in buildings located in hot, arid climates, representing some of the recurring challenges in offices. The study aims to identify the main IEQ factors and their acceptable ranges, including light, thermal comfort, air quality and noise. An IEQ index is utilized (Wagdi et. al 2017) as a tool which assesses the predefined IEQ parameters in office buildings providing a rating scheme which aggregates the obtained readings. Data collected from offices located in Dubai and Cairo is used to assess the indoor environment against defined benchmarks. The full range of parameters was monitored in a group of office spaces and the obtained readings were used to compute the IEQ index. For this investigation, all offices were completely fit out and tests were performed after at least one month of operation. The recorded results demonstrate that with careful design and informed material selection, acceptable IEQ levels can be achieved. The results and application of the index aim to provide an assessment tool to optimize design and construction practices, ultimately improving employee productivity, comfort and health.

Optimizing Indoor Environmental Quality in hot arid climates

Indoor Environmental Quality (IEQ) is a key indicator of the quality of the built environment and the health of its occupants. The purpose of this study is to investigate a range of IEQ parameters in buildings located in hot, arid climates, representing some of the recurring challenges in offices. The study aims to identify the main IEQ factors and their acceptable ranges, including light, thermal comfort, air quality and noise. An IEQ index is utilized (Wagdi et. al 2017) as a tool which assesses the predefined IEQ parameters in office buildings providing a rating scheme which aggregates the obtained readings. Data collected from offices located in Dubai and Cairo is used to assess the indoor environment against defined benchmarks. The full range of parameters was monitored in a group of office spaces and the obtained readings were used to compute the IEQ index. For this investigation, all offices were completely fit out and tests were performed after at least one month of operation. The recorded results demonstrate that with careful design and informed material selection, acceptable IEQ levels can be achieved. The results and application of the index aim to provide an assessment tool to optimize design and construction practices, ultimately improving employee productivity, comfort and health.