Improve Indoor Environmental Quality Research Articles

Growing indoor environmental infrastructure: designing for microbial diversity with implications for pollutant metabolism and human health

Abstract Urban inhabitants spend upwards of 90% of their time indoors where building design and mechanical air-handling systems negatively impact air quality, microbiome diversity and health outcomes. Urban bioremediation infrastructure designed to improve indoor environmental quality by drawing air through photosynthesizing plants and metabolically diverse rhizospheres have been investigated since the 1960s; however, in-depth analysis of the potential impacts on indoor environments is required: (1) although recent evidence has illustrated human microbiome alteration and associated health benefits related to exposure to green wall systems, the mechanism(s) of diversification have not yet been established, (2) microbial metabolism and airborne chemical dynamics are extraordinarily complex and hypotheses pertaining to rhizosphere microorganisms metabolizing pollutants require more attention. To explore these areas, we applied a shotgun metagenomic approach to quantify microbial diversity and establish preliminary metabolic profiles within active green wall modules spanning a range of growth media and plant selections. Results indicate that fundamental design decisions, including hydroponic vs. organic growth media, support rhizosphere microbiomes with distinct diversity and metabolic profiles which could impact system performance. The described relationships indicate fundamental green infrastructure design represents an opportunity to “grow” indoor microbial diversity and metabolisms with potential benefits for human pollutant exposure and health outcomes.

Architecture for Smart Buildings Based on Fuzzy Logic and the OpenFog Standard

The combination of Artificial Intelligence and IoT technologies, the so-called AIoT, is expected to contribute to the sustainability of public and private buildings, particularly in terms of energy management, indoor comfort, as well as in safety and security for the occupants. However, IoT systems deployed on modern buildings may generate big amounts of data that cannot be efficiently analyzed and stored in the Cloud. Fog computing has proven to be a suitable paradigm for distributing computing, storage control, and networking functions closer to the edge of the network along the Cloud-to-Things continuum, improving the efficiency of the IoT applications. Unfortunately, it can be complex to integrate all components to create interoperable AIoT applications. For this reason, it is necessary to introduce interoperable architectures, based on standard and universal frameworks, to distribute consistently the resources and the services of AIoT applications for smart buildings. Thus, the rationale for this study stems from the pressing need to introduce complex computing algorithms aimed at improving indoor comfort, safety, and environmental conditions while optimizing energy consumption in public and private buildings. This article proposes an open multi-layer architecture aimed at smart buildings based on a standard framework, the OpenFog Reference Architecture (IEEE 1934–2018 standard). The proposed architecture was validated experimentally at the Faculty of Engineering of Vitoria-Gasteiz to improve indoor environmental quality using Fuzzy logic. Experimental results proved the viability and scalability of the proposed architecture.

The Impact of Measurable Findings from Pre- and Post-Occupancy Evaluations of Indoor Environmental Quality in the Primary Workspace

This study examined the influence of quantitative and qualitative findings from both a pre-design occupancy evaluation (PDOE) and a post-occupancy evaluation (POE) on the expanded design team’s (designers, client, and researchers) approach to updating the interior work environment. The design team’s implementation of mid-course design solution modifications to the primary workspaces of an engineering group’s environment both after the PDOE and the POE yielded many significant outcomes. The POE was conducted using the same instrument as the PDOE one year after the employees had moved back into their renovated space on a corporate campus. The study’s results were used as a diagnostic tool to improve indoor environmental quality (IEQ) conditions for employees and provided benchmarks for the remaining (85%) campus workplace improvements. The influence and importance of IEQ criteria on employee satisfaction, work performance, and health were demonstrated and contribute to the body of knowledge regarding the influence of the built environment on building occupants. A paired inquiry (PDOE plus POE) helps ensure that human, financial, and environmental resources are appropriated with a higher likelihood of success over POE data alone in terms of meeting current and future employees’ needs and corporate goals.

Green Buildings: Human-Centered and Energy Efficiency Optimization Strategies

The rapid growth of the global population and urbanization has led to environmental degradation, resulting in a worldwide energy crisis. In response, the quality of architecture has evolved to prioritize energy efficiency, impacting indoor human health in the process. Green buildings have emerged as a solution to this problem, aiming to improve indoor environmental quality (IEQ) and human well-being while minimizing negative environmental impacts. This comprehensive review focuses on the role of green buildings in enhancing indoor human health and energy efficiency. It examines the published research on the effects of green buildings on IEQ and occupant health, highlighting sustainable architectural practices that promote good health. The study concludes that green buildings provide healthier environments for their occupants by creating healthy indoor environments, and minimizing negative environmental impacts. The study also explores the link between sustainable architecture and health promotion, with a focus on IEQ. It presents evidence-based and biophilic design strategies that can impact treatments and health promotion in the built environment. Overall, this review emphasizes the critical role that green buildings can play in addressing the global energy crisis while promoting the health and well-being of building occupants.

Indoor environmental quality improvement in green building: Occupant perception and behavioral impact

Previous studies have explored the validity of various design and functioning interventions to improve indoor environmental quality (IEQ); however, there is a lack of empirical studies on what motivates humans to seek better IEQ. To address the challenge, this study aimed to investigate how occupants' perceptions on IEQ can influence their behavioral changes to improve IEQ. A living-lab-based empirical study was conducted in the workspace of a green building built in 2014 in Hong Kong, designed for excellent IEQ. In order to evaluate the occupants' satisfaction with IEQ and their participation in its improvement, two surveys were conducted before and after the workspace's data-driven IEQ information was released to the occupants. According to the main findings, the objective IEQ information can allows the occupants, who had previously shown indifference or a lack of sensitivity to IEQ, to clearly understand their working environment and to create a more comfortable working environment. This study creates new ground in the field of facility management and engineering, focusing on indoor environmental quality improvement, in which occupant perception and behavioral impact can be investigated by deploying an integrated approach using data-driven IEQ reports and questionnaire surveys as well as statistical analysis. This approach will aid in providing guidelines on how to improve the occupants' perceptions on IEQ in the workspace, how to motivate the occupants' participations for IEQ improvement, and how to evaluate the causal effect of increased occupants' interventions on the enhanced indoor working environment. With occupant-tailored facility management systems, occupants will be able to keep track of the objective IEQ status in real time, to maintain a personalized comfortable environment, and to identify any factors that would eventually harm the occupants' health and comfort.

Optimisation of commercial buildings envelope to reduce energy consumption and improve indoor environmental quality (IEQ) using NSGA-II algorithm

In this study, a commercial building envelope is optimised to reduce energy consumption while simultaneously increasing thermal and visual comfort. Design parameters include diameter ratio (ratio of the building large diameter to its small diameter), window to wall ratio (WWR), and orientation. The study is performed for two usages, including retail stores and supermarkets, and three different areas. According to the results, the building performance highly depends on its form. Increasing WWR generally reduces the thermal and visual comforts while increasing energy consumption. To reduce energy consumption and maintain indoor environment quality, the orientation angle of less than 30° is preferable. Also, the effect of building area on the cooling energy consumption is more considerable than the other objectives. Besides, the building usage impacts heating energy consumption noticeably more than other parameters. Finally, the best design parameters are suggested for different usages and areas based on the results.

An intelligent HVAC control strategy for supplying comfortable and energy-efficient school environment

In South Korea, school buildings require significant energy inputs for heating and air-conditioning, and the majority of the occupants are adolescent students, whose health and cognitive performance are vulnerable to poor indoor air quality (IAQ) and thermal discomfort. Using field measurements, some previous studies have reported that some Korean schools have poor IAQ and thermal conditions. Thus, it is necessary to develop effective heating, ventilation, and air-conditioning (HVAC) control strategies to improve the indoor environment and reduce energy consumption. Therefore, this study proposes an intelligent HVAC integrated control strategy that can improve indoor environmental quality (IEQ) and reduce energy consumption in school buildings. The proposed strategy utilizes an integrated neural network prediction model for IEQ and a heuristic method that can optimize control objectives (i.e., the predicted mean vote [PMV], carbon dioxide [CO2], particulate matter with diameters of 10 and 2.5 μm [PM10 and PM2.5, respectively], and HVAC energy consumption). To evaluate the control performance of the proposed strategy, the present study employs two base algorithms (i.e., a rule-based and a non-adaptive control approach) under non-disturbance and forcing disturbance scenarios. The control failure period for PMV is found to be 1.6420% and 9.4773% of the total occupancy period under the non-disturbance and forcing disturbance scenarios, respectively, while CO2 control failure does not occur under either scenario. The control failure periods for PM10 and PM2.5 were 5.1676%, and 7.1844%, respectively, under forcing disturbance. Under the non-disturbance scenario, the proposed strategy consumed 2,467.07 kWh and 870,26 kWh for heating and cooling, respectively, representing 91.1% and 84.08% of that for the rule-based algorithm. The proposed strategy can thus effectively improve the IEQ of a building and has the potential for use in the development of integrated environmental management solutions for buildings.

A Pilot Study on the Combined Multi-domain Impact of Indoor Air Quality and Noise on Office Productivity

As people spend 90% of their time indoors, it was necessary to improve indoor environmental quality to enhance human productivity. Indoor environmental quality consists of indoor air quality (IAQ), thermal, visual, and acoustic comfort. However, only a few studies have investigated the combined effects of IAQ and noise. During and after the COVID-19 pandemic, portable air cleaner is often used in buildings to reduce the concentration of particles in the air, but it also generates noise. The objective of this study is to determine the effects of a portable air cleaner on IAQ and noise level, and more importantly the resulting combined effects on office productivity. For this purpose, we conducted human subject tests in an office and each test lasted for 1.5h. For each case, the air temperature, relative humidity, and supply airflow rate were kept constant while the air cleaner was switched between on and off for various noise levels and IAQ. We recruited 7 participants and collected data on the concentration of CO2, particles, and TVOC every 5 minutes. We used wristbands to measure heart rate and skin electrodermal activity. And we used headbands to measure electroencephalogram (EEG) and facial activity. The questionnaire survey was used to learn the occupants’ responses to the indoor environment. To learn their productivity, occupants also did math addition tasks and typing tasks. We found that when using the portable air cleaner, the noise level raised from 55dB to around 70dB. The particle and TVOC concentrations were reduced by 90% and 20%, respectively. The questionnaire survey showed that the occupants felt unsatisfied due to noise. And the noise dissatisfaction exceeded the improved IAQ. By analyzing the EEG and the number of jaw clenches, the occupants felt more nervous and concentrated when the air cleaner was on. We confirmed the impact of noise and the combined impact of IAQ and noise on office productivity.

Indoor Thermal and Ventilation Indicator on University Students’ Overall Comfort

Thermal comfort (TC) and CO2 concentration significantly influence the overall indoor comfort sensations of building occupants. However, few studies have focused on educational buildings regarding both TC and CO2 concentration in tropical regions, and they also lack guidelines for short-term evaluation, which is essential for university classrooms. In this study, a mechanically ventilated university classroom was selected to investigate the 5 min-averaged comfort ranges for indoor parameters and the impacts of TC and variation of CO2 on student overall comfort. The real-time indoor environmental parameters were monitored, including indoor air temperature (Ta), mean radiant temperature (Tm), relative humidity (RH) and CO2 and air velocity (va); the operative temperature (Top) was calculated. Moreover, an online-based questionnaire survey related to thermal sensation (TS) and CO2-related air sensation (AS) was carried out. Linear and nonlinear regression models of comfort sensation predictions were obtained based on the questionnaires and corresponding measured indoor environmental data. The 5 min-averaged comfort ranges for Top, CO2 and RH are 21.5–23.8 °C, <1095 ppm and 47–63.5%, respectively. The comfort range of the TS and AS are 2.3–3.1 and 1–1.55, respectively. The result shows that students prefer a relatively cold indoor environment, as this improves their ability to tolerate bad indoor air quality (IAQ) with high CO2. A regression analysis indicated that AS is the most critical aspect, with a weight of 0.32, followed by TS, with 0.18. Finally, it was also found that individual weighting coefficients were not equivalent and differed across geographical locations and building types. Thus, obtaining the prediction models for a particular building is necessary. The results can give meaningful suggestions to adopt the appropriate operations for HVAC and improve indoor environmental quality in university buildings in tropical regions.

Characteristics of eye movements while viewing indoor plants and improvements in occupants' cognitive functions

AbstractPlants improve indoor environmental quality as a visual factor and enhance occupants' overall well‐being. However, research on the mechanisms by which plants improve human cognitive function is limited. This study examined the characteristics of eye movement while viewing indoor plants and their relationship with the cognitive benefits of plants. Thirty students performed cognitive tasks in four desktop conditions: no objects, real plants, artificial plants, and books. Eye movements while viewing plants during rest times in the reading span task (RST), which requires working memory, were characterized by a lower number of fixations, frequent dispersion of fixation points, and a higher number of blinks. Females showed higher RST scores under the real plant condition than under the no‐object condition. These results are consistent with the assumption that plants require lower cognitive effort and better restoration of attention capacity. In addition, in the real plant condition, females showed higher RST scores than males, and only females showed higher creativity scores than those in other conditions. Therefore, gender differences in the cognitive benefits of plants have been suggested. This study provides new insights into the effects of indoor plants on occupants' cognitive functions by quantifying visual perception processes using eye‐tracking technology.

Iterative Optimization of a Social Inmotics-Based Method in Order to Make Buildings Smart and Resilient

• Social inmotics as a disruptive force to transform consumption habits and improve IEQ • An easy-to-develop method driving gradual improvements in IoT in resilient buildings • Inclusion of evaluation indicators validates the consequences of action strategies • A scalable, adaptable, low-cost, upgradeable and open source cyber-physical system The current situation of inefficiency in buildings operation, inadequate occupants’ habits and the low Indoor Environmental Quality suggests a methodology that addresses the implementation of social inmotics. The method allows the continuous optimization of the building performance and occupants’ awareness through an iterative process. In each iteration the experts propose strategies that will be evaluated in the next cycle through key performance indicators. This method develops an open source, scalable, low-cost cyber-physical system using real time data. The results have been obtained from successive approaches, implementation of protocols and empirical validation in different scenarios until reaching the version of the system installed in a public university building, the School of Technology (University of Extremadura, Spain). By testing this methodology, social inmotics through the use of disruptive technologies is proving to find solutions that increase energy savings and improve Indoor Environmental Quality in adaptive and resilient buildings. Some of the results show that electricity and water consumption with respect to occupancy density have decreased, important and unexpected consumption peaks as the data servers, the cafeteria, or breakdowns have been detected, and users’ participation improve the initial situation. Furthermore, this paper provides key performance indicators for this building typology.

Methodological approach and comparative analyses for smart envelopes assessment in three different temperate climates

Recently, innovative and responsive technologies applied to building envelopes have drawn the attention of researchers to reduce energy consumption and improve indoor environmental quality. The main feature of these systems is to react to external environmental stimuli and adapt themselves to improve the overall building performance. The spread of these technologies has promptly led to a wide range of very different new devices that have added a further degree of complexity in the energy efficiency field. This study is part of this research topic and proposes a comparison of four different responsive technologies applied to glazed surfaces of an office model located in three different Italian cities to compare their advantages and disadvantages in different contexts. This comparison is conducted from both technological and energy points of view on the following selected technologies: i) electrochromic windows, ii) Phase Change Material windows, iii) dynamic automated external shadings, and iv) windows with variable thermal transmittance. The first part of this study focuses on the technology comparison – with reference to users' control, building integration, cost, and maintenance – to highlight the main strengths and disadvantages of these systems. Hence, starting from an office reference model located in Brindisi, Rome, and Milan, dynamic energy analyses are conducted in EnergyPlus to compare the responsive systems with reference static envelopes obtaining as the final output the savings comparison between different technologies, exposures, and climates.

Evaluation of a Polyester Filter and UV Light (PFUV) Dehumidifier to Improve Indoor Environmental Quality: Preliminary Results

Older residential dwellings in New Zealand frequently suffer from poor indoor environmental quality (IEQ) due to an ageing housing stock. Recent New Zealand surveys indicated around 50% of children live in houses that do not meet acceptable standards for thermal comfort. Children in these houses frequently experience respiratory conditions caused by dampness and mould during winter. New regulatory standards requiring a fixed heating source in the main living room of rental houses can increase rents and may result in the heating source not being utilized. This study evaluates an alternative low-cost portable air filter/sterilizer (PFUV) dehumidifier device for improving IEQ within the building envelope using Ultraviolet Germicidal Irradiation (UVGI) and a polyester filter (dual-10 30/30). This paper compares the effectiveness of the PFUV dehumidifier device and a conventional heat pump in terms of measured particulate matters as well as fungal profiles using Potato Dextrose Agar (PDA) plates. The PFUV dehumidifier successfully reduced the relative humidity to within a healthy range of (44–49%) compared to not running the device (54–60%), thereby reducing the suitability of the environment for mould growth. Additionally, the PFUV device achieved a reduction in average particulate matter (PM2.5) to within the range of 0.16 to 0.53 µg/m³ compared to the range of 1.06 to 2.42 µg/m³ before using the device.

An explanatory parametric model to predict comprehensive post-commissioning building performances

Existing building commissioning (EBCx) is a promising approach to save energy and improve indoor environmental quality (IEQ) without sufficient attention yet. However, the uncertainty of building performance post-retrofit leads to a low adoption rate of EBCx, as the commissioning outcomes are dependent on various factors and difficult to model. To facilitate decision-making on EBCx, this paper introduces PECCO, a parametric mathematical model enriched with years of commissioning engineering experience to predict comprehensive EBCx outcomes for various types of public buildings, along with a mobile-based tool to automate the prediction process. An 8-min questionnaire is used to collect building parameters regarding general, management, HVAC, smart system, IEQ, electrical, water supply, and building envelope. Then, a mathematical model predicts commissioning outcomes including energy-saving potential, annual cost saving, asset value increase, comfort-improvement potential, operation risk, commissioning cost, simple payback period, and difficulty in commissioning, and provides overall commissioning strategies, specific commissioning suggestions, and benchmark figures compared with other buildings. Three case studies suggested that PECCO's prediction on the simple payback period achieved a mean absolute percentage error (MAPE) of 15.47%, which is acceptable and comparable to other related studies. By providing various perspectives of information to building owners and managers, PECCO is helpful to foster the industry to undertake EBCx, leading to a more energy-efficient, low-carbon building industry.

Protocol for Post Occupancy Evaluation in University Campus Classroom to Improve Indoor Environmental Quality

Protocol for Post Occupancy Evaluation in University Campus Classroom to Improve Indoor Environmental Quality

Assessment of older adults’ acceptance of IEQ in nursing homes using both subjective and objective methods

Due to accelerated population ageing, the demand for nursing homes has greatly increased in China. As older adults spend most of the day indoors, it is of great importance to improve indoor environmental quality (IEQ) to provide a comfortable living environment for senior residents in nursing homes. Therefore, this study aims to investigate older adults' acceptance of the IEQ in nursing homes using both subjective and objective methods. A questionnaire survey was conducted to collect subjective acceptance levels regarding IEQ in nursing homes (including air temperature, relative humidity, indoor air quality (IAQ), visual environment, and acoustic environment). Objective data on five environmental parameters (i.e., air temperature, relative humidity, CO2 concentration, illuminance level, and noise level) were collected using a wireless sensor network (WSN) system. A machine learning predictive model was established to assess IEQ acceptance on the basis of the data from the questionnaire survey and the WSN. The results showed that subjective assessments on five aspects of IEQ and objective measurements on five environmental parameters were related to overall IEQ acceptance. Air temperature had the greatest impact on the overall IEQ acceptance, while visual environment and illuminance level had the least influence. The study offers useful information on improving IEQ in nursing homes and helping to enhance older adults’ quality of life.

Comfort and technical installations in Danish low-energy homes: reconnecting design intention and domestic perceptions

ABSTRACT In order to reduce energy use and improve indoor environmental quality (IEQ), new and retrofitted dwellings are increasingly equipped with complex heating and mechanical ventilation solutions, which occupants have to learn to use and live with. This work investigates the different ways in which occupants integrate these technologies into daily domestic practices, the associated difficulties and their potential consequences on comfort and building performance. Semi-structured interviews were carried out with occupants of 37 new and retrofitted low-energy dwellings around Copenhagen (Denmark), focusing on occupants’ domestication of underfloor heating and mechanical ventilation. While most respondents were largely satisfied with the IEQ in their homes, the interviews highlighted a disconnection between expected and real uses and perceptions of these technologies. The design assumptions were sometimes unable to reflect occupants’ expectations, including regarding personal control needs. Moreover, installation and operational failures were frequent and difficult for users to diagnose and correct, as they lacked relatable technical guidance. Consequently, occupants often resorted to alternative ways of taking control, which could prove detrimental for energy use and IEQ. The findings highlight the need for incorporating interdisciplinary insights on in-use performance in the design and installation of building systems, making them more robust, reliable and transparent.

How using smart buildings technology can improve indoor environmental quality in educational buildings

An educational building must integrate smart building strategies to ensure indoor environmental quality. Thermal, acoustic, visual comfort and indoor air quality are to be considered, otherwise they can develop the sick building syndrome. Smart buildings solve this potential problem by providing a highly efficient living ambience that includes safety, comfort and a good quality of living/learning/working experience, that helps the users achieve their best possible performance. These buildings should integrate advanced technologies such as automated systems and the implementation of architectural skins, well and functional designed spaces and architectural features that act as active bioclimatic solutions. The following is a case study of an architectural project for an elementary and junior high school academic campus in the state of Nuevo León, Mexico that has to deal with the extreme climate conditions of the location, while applying the best alternative and bioclimatic strategies through the implementation of inmotics, a responsive architectural skin, sustainable construction systems and native vegetation. In doing so, a comprehensive environmentally friendly building is created, taking advantage of the surrounding natural conditions, using the latest environmentally oriented systems and technologies. The result is a healthy, safe, and productive space for its users that greatly benefits the teaching-learning process.

Dynamic Energy Performance Gap Analysis of a University Building: Case Studies at UAE University Campus, UAE

As a result of an increasing demand for energy-efficient buildings with a better experience of user comfort, the built environment sector needs to consider the prediction of building energy performance, which during the design phase, is achieved when a building is handed over and used. There is, however, significant evidence that shows that buildings do not perform as anticipated. This discrepancy is commonly described as the ‘energy performance gap’. Building energy audit and post occupancy evaluation (POE) are among the most efficient processes to identify and reduce the energy performance gap and improve indoor environmental quality by observing, monitoring, and the documentation of in-use buildings’ operating performance. In this study, a case study of UAE university buildings’ energy audit, POE, and dynamic simulation were carried out to first, identify factors of the dynamic energy performance gap, and then to identify the utility of the strategy for reducing the gap. Furthermore, the building energy audit data and POE were applied in order to validate and calibrate a dynamic simulation model. This research demonstrated that the case study building’s systems were not operating as designed and almost a quarter of the cooling energy was wasted due to the fault of the building facility management of the mechanical systems. The more research findings were discussed in the paper.

Tenant perceptions of post-renovation indoor environmental quality in rental housing: Improved for some, but not for those reporting health-related symptoms

Much of the 1950–1970s building stock in Sweden and other European countries is being renovated to reduce energy use and for general upgrading. To realize the UN Sustainable Development Goals, the renovations should also improve indoor environmental quality (IEQ). The PEIRE (People-Environment-Indoor-Renovation-Energy) study followed the renovation of a multifamily housing area in Sweden comprising 14 buildings with 323 dwellings in total. We aimed to investigate tenant perception of IEQ changes after the renovation with focus on perceived control of IEQ, recalling of being informed how to control IEQ, and if tenants with self-reported symptoms perceive the changes differently. A post-renovation survey (n = 104, response rate 36%) showed that the renovation increased the proportion of residents experiencing satisfactory thermal comfort and air quality in the winter, as well as improved noise conditions. Perceiving reduced draught in the thermal environment was associated with experiencing being informed and being able to control heat and ventilation. Respondents reporting skin irritation symptoms were less likely than others to perceive any improvements of IEQ factors such as air quality, daylight, noise from installations and neighbours, and periods of excessive heat. Renovations targeting housing sustainability – here, decreasing energy use and mitigating wear and tear while keeping the rents low – could increase tenant perceptions of improved IEQ, especially if factors concerning information and tenants’ ability to control the regulating systems are addressed. Interestingly, results of this study point out that tenants experiencing IEQ-related symptoms may require enhanced IEQ improvements to experience the renovation as satisfactory.