Building Indoor Environmental Quality Research Articles

A Systematic Review on the Use of AI for Energy Efficiency and Indoor Environmental Quality in Buildings

Global warming, climate change and the energy crisis are trending topics around the world, especially within the energy sector. The rising cost of energy, greenhouse gas (GHG) emissions and global temperatures stem from the over-reliance on fossil fuel as the major energy resource. These challenges have highlighted the need for alternative energy resources and urgent intervention strategies like energy consumption reduction and improving energy efficiency. The heating, ventilation, and air-conditioning (HVAC) system in a building accounts for about 70% of energy consumption, and a decision to reduce energy consumption may impact the indoor environmental quality (IEQ) of the building. It is important to adequately balance the tradeoff between IEQ and energy management. Artificial intelligence (AI)-based solutions are being explored for improving building energy performance without compromising IEQ. This paper systematically reviews recent studies on AI and machine learning (ML) for building energy management and IEQ by exploring common use areas, the methods or algorithms applied and the results obtained. The overall purpose of this research is to add to the existing body of work and to highlight energy-related AI applications in buildings and the related gaps. The result shows five common application areas: thermal comfort and indoor air quality (IAQ) control; energy management and energy consumption prediction; indoor temperature prediction; anomaly detection; and HVAC controls. Gaps involving policy, real-life scenario applications, and insufficient study of the visual and acoustic comfort areas are also identified. Very few studies take into consideration the need to follow IEQ standards in the selection process and positioning of sensors in AI applications for IEQ in buildings. This study reveals a need for more systematically summarized research.

Improving indoor environmental quality in an affordable house by using a vegetated wall: A case study in subtropical Brazil

Indoor environmental quality of buildings, including thermal, acoustic, visual comfort, and air quality, directly impacts the comfort, health, and productivity of occupants. However, in Brazil, the high deficit of affordable housing units has led to a situation where environmental quality is often overlooked in favour of low investment costs, prioritizing quantity over quality. Furthermore, the poorest segments of the population, who rely on affordable housing, are disproportionately affected by energy costs. Therefore, it is crucial to conduct research on low-cost energy solutions for social housing to improve the sustainability of people's lives. In this light, a study was conducted to monitor the energy performance of a vegetated wall made of deciduous species and compare it to a bare wall used in an affordable house in subtropical Brazil. Parameters, such as internal and external surface temperatures, nearby microclimatic conditions, and heat transfer through the vegetated and bare walls, were monitored every 5 min over a two-year period. The heat flux analysis revealed that the vegetated wall reduced conductive heat up to 83 % during summer days, significantly lowering the external surface temperature by 8.6 °C due to the presence of the plant layer. Moreover, the vegetated wall generally exhibited lower shortwave and longwave radiative and convective heat fluxes. These findings contribute to our understanding of energy transfer through vegetated walls in subtropical Brazil, including the impact of adjacent microclimatic conditions. Furthermore, the results confirm the potential of vegetated walls to effectively reduce cooling and heating demands at a minimal additional cost.

Window state or action modeling? An explainable AI approach in offices

Window operation significantly impacts energy use and indoor environmental quality in buildings. Individuals behave differently, making it difficult for models trained on a specific dataset to encompass the entire spectrum of these actions. A generalizable model is essential to predict the behavior of diverse occupants in office spaces. To address this need, this paper presents a systematic approach that captures this diversity, thereby contributing to developing a model towards generalizability. The approach involves state and action modeling through a Random Forest algorithm on the ASHRAE Global Occupant Behavior Database. The data pre-processing, hyperparameter tuning, and evaluation are deeply described and applied to window action and state datasets.Our results demonstrated that including metadata in a state model and applying a G-Mean threshold moving technique can result in an F1-score of 0.74. This score slightly outperformed the state room-wise model, which was trained only on its own dataset and achieved an F1-score of 0.73. However, both models had similar accuracies of 77%. The action model did not fare as well as the state models, with an F1-score and accuracy score of just 0.42 and 49%, respectively. In contrast, the action model showed more explainable results for domain experts than state models.

A Study on Indoor Environmental Quality

Günümüzde insanlar zamanlarının büyük bölümünü konut, ofis, okul gibi kapalı mekânda geçirmektedir. Son yıllarda yaygın olarak görülen hasta bina sendromu, bina kaynaklı hastalıklar, okullarda öğrenim performansının ve ofis ortamlarında çalışanların verimliliklerinin azalması gibi sağlık ve verimlilik sorunları iç ortam kalitesi ile ilişkilendirilmektedir. Bu çalışmada iç ortam kalitesi ve sürdürülebilir bina kavramları ilişkilendirilerek, insan sağlığı ve verimliliği konularında iç ortam kalitesinin (iok) önemine dikkat çekmek amaçlanmaktadır. Bu çalışma kapsamında iok’ni belirleyen parametrelerden aktif olarak ölçülebilen ve kontrol edilebilen ısıl konfor, iç hava kalitesi, aydınlatma ve görsel konfor, akustik konfor ele alınmıştır. İok ile ilgili standart ve literatür taraması ile elde edilen bulgular sonucunda bu parametrelerin tanımları, kullanıcı üzerindeki etkileri, ölçülme yöntemleri ve yeşil bina sertifikasyon sistemleri ile ilişkileri ele alınmıştır. Sonuçta, iok'nin çalışmada ele alınan temel parametrelerinin, bina kullanıcılarının sağlığı ve üretkenliği ile ilişkili olduğu; dikkate alınmasında önemli sağlık ve finansal yararlar olduğu; iç ortamdaki fiziksel koşulların, uygun tasarım ve bina işletim sistemleri ile karşılanabileceği, yeşil bina sertifika sistemlerinin binalarda iok’nin gelişimine katkı sağladığı sonuçlarına ulaşılmıştır.

Weighting of indoor environment quality parameters for occupant satisfaction and energy efficiency

Sustainable retrofit can increase a building's performance and extend its lifetime. Common sustainable retrofit guides usually ignore the building's indoor environmental quality (IEQ) and occupant satisfaction while only focus on the energy efficiency. During the retrofit, prioritizing improvements to IEQ parameters that are critical for increasing occupant satisfaction but do not considerably increase energy consumption is crucial given the budgetary constraints. This project aims to identify different building experts' perspectives on the impact of IEQ factors and underlying parameters that contribute to occupant satisfaction and energy efficiency in office buildings, and develop an index that ranks the IEQ parameters' overall cost-effectiveness in a sustainable retrofit. The study surveys the views of 30 carefully selected building experts (ten architects, ten building engineers, and ten building assessors) in Australia using multiple criteria decision-making method. Results show that the building engineers and assessors regard thermal comfort as the most critical factor influencing occupant satisfaction, 54.2% and 57.6%, respectively. Alternatively, the architects regard visual comfort as the most important (38.8%). All expert groups have a similar opinion on the relative importance of IEQ factors in office energy consumption. An IEQ Effectiveness index is developed to evaluate the cost-effectiveness of improving a specific IEQ parameter in achieving high occupant satisfaction while not demanding extra energy input. Visual and acoustic IEQ parameters turn out to be ideal IEQ parameters that can be prioritized in a retrofit. Results from this study can provide guidance for the decision-making process of the office building sustainable retrofit.

Multi-domain indoor environmental quality in buildings: A review of their interaction and combined effects on occupant satisfaction

Occupant satisfaction is influenced by the interaction and combined effects of multi-domain indoor environmental quality (IEQ) in buildings. While there are literature reviews on multi-domain IEQ, two limitations exist: 1) the reviewed IEQ interactions are mainly limited to two IEQ domains and climate chamber studies; and 2) those reviews have not quantitatively discussed the impact of IEQ interactions on overall satisfaction and only cover limited building types. To address this gap, this study adopts a broad, top-down approach with a three-stage screening to select relevant publications about the four most concerned IEQ domains—thermal comfort, acoustic comfort, visual comfort, and indoor air quality. A total of 74 publications have been selected and reviewed. Our study shows that: 1) existing findings on IEQ interaction and combined effects are inconsistent and somewhat contradictory; 2) interactions among three IEQ domains exist but are much less examined compared to two IEQ interactions. Studies on four IEQ are not found; 3) the current occupant satisfaction models are mainly generalized models. Personal models are an emerging area of research and practice; and 4) the one-vote veto effect exists, i.e., some IEQ domains show a predominating influence on overall satisfaction. We advocate future research 1) to collaborate on a global IEQ database to enable model comparison and the development of standards and guidelines spanning multiple IEQ domains, 2) to investigate personal overall satisfaction models encompassing IEQ interactions; and 3) to further examine non-linear modeling approaches for interpreting the relationships between IEQ and overall satisfaction.

Experimental performance evaluation of a climate-responsive ventilated building façade

Enhancing building energy performance has become a focal point in reducing the environmental impacts of buildings to address climate change. Considering the high share of comfort-related energy use in buildings, and the importance of indoor environmental quality (IEQ), a balance between energy conservation and IEQ provision is required. Building façades are the primary boundary controlling mass and energy flow to and from buildings. Dynamic and climate-responsive façades are potential improvements to existing high-performance façades to enhance IEQ in buildings, as they change their functionality with time, in response to changing environmental loads. A multifunctional, integrated, climate-responsive, opaque, and ventilated building façade (MICRO-V) was designed to regulate the flow of heat, air, and moisture into buildings. The MICRO-V façade has a novel design to pre-condition the fresh air and regulate thermal loads in buildings on a daily and seasonal basis. The multiple components of this façade include phase change materials (PCMs), a bi-directional ventilation module and an adjustable insulation system. In this paper, the thermal performance of this façade was evaluated using long-term experimental tests. The real-scale prototype of the façade was constructed and installed in the full-scale BETOP test cell facility in Toronto, Canada. The results of different tests showed how the façade could pre-condition the fresh air acting as a decentralized ventilation module due to a high heat recovery efficiency of 81%. However, it was also shown that the significant impact of solar irradiance, which requires constant adjustment to the operation schedule of the ventilation fans in the façade.

Global Research Trends on Building Indoor Environmental Quality Modelling and Indexing Systems—A Scientometric Review

The purpose of this study is to provide a holistic review of two decades of research advancement in the indoor environmental quality modelling and indexing field (IEQMI) using bibliometric analysis methods. The explicit objectives of the present study are: (1) identifying researchers, institutions, countries (territories), and journals with the most influence in the IEQMI topic; (2) investigating the hot topics in the IEQMI field; and (3) thematically analysing the keyword evolution in the IEQMI field. A scientometric review was conducted using the bibliometric data of 456 IEQMI research articles published in the past two decades. VOSviewer software was employed for bibliometric analysis, and the SciMAT tool was used to investigate the keywords’ thematic evolution in three sub-periods (2004–2009; 2010–2015; 2016–2021). Results show that there is a continuous increment in the number of published papers in the field of IEQMI, and 60 out of 193 countries in the world have been involved in IEQMI studies. The IEQMI research mainly focuses on: (a) thermal comfort and energy efficiency; (b) occupant satisfaction and comfort; (c) IAQ and health issues; (d) methods and procedures. This field has undergone significant evolution. While ‘indoor environmental quality was initially the only theme in the first period’, ‘occupant satisfaction’, ‘buildings’, ‘impact’, ‘building information modelling’, and ‘health’ were added as the main thematic areas in the second period; ‘occupant behaviour’ and ‘energy’ were novel themes in IEQMI studies receiving much attention in the third period.

The effect of indoor environmental quality on the productivity of factory workers: A case of pharmaceutical factories in Southwest Nigeria

The indoor environment of pharmaceutical factory building is known to be a very active place with industrial equipment, machineries, full of light, noise, particulate matter, and other gaseous elements. Having this all-in-one place can be a challenge to the wellbeing and possibly the productivity of the workers of the factory. As a result, the study investigated the effect of indoor environmental quality (IEQ) on the productivity of the pharmaceutical factory workers. This review of relevant literature from e-books, articles, conference proceedings, technical reports, textbooks, thesis and periodicals was conducted between 2010-2022. 14 pharmaceutical factories were investigated within 13 months (October 2020-November 2021). The factors of indoor environmental quality influencing workers’ wellbeing as well as their productivity, were thoroughly investigated using a strategic procedure. It was discovered that the factors involved in a pharmaceutical factory building's IEQ and the productivity factors of the workers were complex and diverse. This paper concludes that the previous studies reviewed do not show that indoor environmental quality of PFB have any significant impact on the productivity of the pharmaceutical factory workers.

Commercial building indoor environmental quality models: A critical review

Indoor environmental quality (IEQ) models merge various influencing IEQ factors into a single overall indicator. The outcome of the IEQ model is usually a numerical rating or score that provides an evaluative summary of the IEQ performance. Many publications have developed IEQ models from their field measurement and/or satisfaction survey results, however with distinct measurement protocols, IEQ weighting schemes and analytical methods. This paper presents a comprehensive review of 25 studies focusing on developing IEQ evaluation models in commercial buildings. Two IEQ measurement approaches (objective and subjective measurement), and three types of IEQ models—subjective-objective models, objective models and subjective models—are first differentiated. Five commonly used analytical methods (linear regression, non-linear regression, analytical hierarchy process, ensemble averaging method, and updated IEQ acceptance model) are discussed. The interaction effects between IEQ factors and relative contribution of them to the overall IEQ satisfaction are also assessed. Twenty-five studies are then mapped by data collection method, analytical method and number of survey responses. Five key criteria for developing quality IEQ models—number of IEQ factors included, spatial and temporal variability in physical measurement, analytical methods for model development, and the number of responses if subjective surveys are carried out—are proposed and discussed. A simple ranking and scoring system is propounded for evaluating the quality of the IEQ models developed in the reviewed studies. Results show that two studies achieved a total score equal to or higher than 80% of the total score, and 16 studies achieved a minimum of 60% of the total score. This tool can help researchers quickly assess the accuracy and reliability of IEQ models developed from diverse methods and make an informed decision.

PredicTAIL, a prediction method for indoor environmental quality in buildings undergoing deep energy renovation based on the TAIL rating scheme

The recently developed TAIL rating scheme enables assessment of the changes in the indoor environmental quality (IEQ) associated with a building’s deep energy renovation (DER) and classification of the resulting quality levels of the thermal (T), acoustic (A), and luminous (visual) (L) environments and indoor air quality (I). Since the TAIL rating is primarily based on measurements, it cannot be determined prior to renovation operations to help design the IEQ. To fill this gap, the PredicTAIL method was developed in the present study to predict the changes in ten of the twelve TAIL parameters as a result of DER. These parameters are indoor air temperature, relative humidity, sound pressure level, daylight factor, illuminance, and concentrations of carbon dioxide, formaldehyde, benzene, radon, and PM2.5; no prediction is made for ventilation rate or mold. To examine the feasibility of the PredicTAIL method and the sensitivity of the existing models for quantifying changes in the TAIL parameters corresponding to different renovation strategies, simulations were performed in a hotel and an office building using TRNSYS, IDA ICE, ACOUBAT, MATHIS-QAI, and PHANIE. These modeling tools were first benchmarked against the TAIL parameters measured in the buildings before renovation. Once the agreement between measurements and modeling was considered acceptable, four pragmatic renovation scenarios were applied, and their impact on the IEQ parameters was quantitatively modeled. The simulations showed that the quality levels of the IEQ parameters were improved or unchanged for some parameters but degraded for other parameters after DER. The changes in the IEQ parameters and the TAIL rating depended on the renovation scenarios, suggesting that the PredicTAIL method is sufficiently sensitive to guide renovation design.

The CORE-CARE laboratory to investigate the indoor environmental quality in buildings

In this work, the climatic chamber CORE-CARE is presented. The laboratory was built at the Industrial Engineering Department of the University of Padova, in order to further investigate issues related to indoor environmental quality, the comfort perceived by people in confined spaces and thermal performance of radiant systems. CORE-CARE is equipped with radiant panels in each surface, which can be controlled separately. The room presents two real windows on the East side, equipped with shading systems. Furthermore, the mechanic controlled ventilation system installed in the room can act as integration of sensible or latent heat both in heating and in cooling conditions. The climatic chamber is provided with a data acquisition system, consisting of 38 sensors, that allow the evaluation of the surface temperatures in different positions, the air temperature at different heights, the mean radiant temperature, relative humidity and CO2 concentration. The CORE-CARE chamber is thermally characterized using a detailed model developed at the Industrial Engineering Department of the University of Padova and the simulations results are compared with test measurements. Moreover, the impact of radiant asymmetry is investigated.

Simulation of passive ventilation strategies towards indoor CO2 concentration reduction for passive houses

Population awareness and economic growth are responsible for the increasing requirements of indoor thermal comfort in buildings. However, the use of active systems to ensure indoor thermal comfort, contributes for the building sector to be responsible for high levels of energy consumption and consequently greenhouse gas emissions. Passive Houses are one step forward towards low energy demand and indoor environmental quality in buildings. Airtightness of the building's envelope is one of the major PH requirements, that in association with the mechanical ventilation system are responsible to assure adequate ventilation levels. These parameters result in additional challenges towards PH applications in Mediterranean and warm subtropical climates due to the overheating risk, providing new opportunities to explore potential night ventilation strategies. This study is focused on the analysis of different passive ventilation strategies towards indoor CO2 concentration reduction preventing overheating risk, thus assuring high levels of indoor environmental quality. The adopted methodology relied on collected data acquired from interviews performed to Passive Houses residents as the starting point, to identify their major expectations as well as complaints and concerns regarding indoor environmental quality. Following the interviews analysis, whole building dynamic simulation was performed using as a case study a PH building constructed in Cyprus (Tseri Passive House). Three different ventilation scenarios were evaluated: original settings (scenario 1); mechanical ventilation active during the day and turned off during the night (scenario 2); natural night ventilation (scenario 3). An ideal scenario, considering night ventilation through window openings, in which indoor CO2 concentration never exceeded the normative limit of 1000 ppm during a summer design week was achieved.

HIEQLab, a facility to support multi-domain human-centered research on building performance and environmental quality

Researches on building performances and environmental quality can be performed through different approaches, including dynamic numerical simulations, in-field studies, full scale test facilities and living labs. Researches performed through full scale test facilities allow carrying out studies under controlled realistic conditions, directly involving the final users. Such approach can significantly improve the scientific research on energy efficient and healthy buildings by fostering a synergistic and user-centered innovation process. Within this context, at Politecnico di Torino, the TEBE group (Technology, Energy, Building and Environment) has designed and is realizing a full-scale facility, aimed at implementing researches on building Indoor Environmental Quality (IEQ) and energy performance. The facility will enable multi-domain studies, including thermal, air quality, acoustic and lighting aspects, involving the final user in the research process. The paper describes the features of the facility and the challenges it was conceived to face.

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.

Novel Technologies to Enhance Energy Performance and Indoor Environmental Quality of Buildings

Here, we overview the Buildings journal Special Issue dedicated to the following topic: “Novel Technologies to Enhance Energy Performance and Indoor Environmental Quality of Buildings” (https://www [...]

Economic Evaluation of the Indoor Environmental Quality of Buildings: The Noise Pollution Effects on Housing Prices in the City of Bari (Italy)

Among environmental factors, noise represents one of the most relevant determinants on human health and on the urban quality level and, consequently, on real estate values. Thus, the noise pollution issue plays a significant role in public urban policies aimed at increasing the acoustic comfort level and creating more sustainable and comfortable cities. The real estate market is highly sensitive to noise factor and the residential prices can be strongly influenced by a high acoustic pollution rate. The present research aims to analyze the functional relationships between noise pollution and selling prices in four municipal areas of the city of Bari (Southern Italy). For each area, a study sample constituted by two hundred residential properties sold in 2017–2019 was detected for the identification of the main influential factors on prices and the investigation of the contribution of noise on them. The implementation of an econometric technique was used to obtain four different models (one for each municipal area of the city of Bari) able to explain the specific impact of noise pollution level on selling prices. From the comparison of the results obtained for each area, the outputs confirm the expected phenomena in terms of a decrease of noise component influence on residential prices from the central area to the peripheral. For the suburban area of the city of Bari, the model obtained does not include the noise pollution factor, showing a lower (scarce) importance of the environmental factor among the buyer and seller bargaining phases.

Methodology for Simultaneous Optimization of the Thermal, Visual, and Acoustic Performance of Building Envelope

Abstract Thermal, visual, and acoustic comfort are among the major parameters of overall occupant comfort and indoor environmental quality in buildings. Early stage design and selection of building...

Investigating the indoor environmental quality of different workplaces through web-scraping and text-mining of Glassdoor reviews

ABSTRACT The analysis of occupants’ perception can improve building indoor environmental quality (IEQ). Going beyond conventional surveys, this study presents an innovative analysis of occupants’ feedback about the IEQ of different workplaces based on web-scraping and text-mining of online job reviews. A total of 1,158,706 job reviews posted on Glassdoor about 257 large organizations (with more than 10,000 employees) are scraped and analyzed. Within these reviews, 10,593 include complaints about at least one IEQ aspect. The analysis of this large number of feedbacks referring to several workplaces is the first of its kind and leads to two main results: (1) IEQ complaints mostly arise in workplaces that are not office buildings, especially regarding poor thermal and indoor air quality conditions in warehouses, stores, kitchens, and trucks; (2) reviews containing IEQ complaints are more negative than reviews without IEQ complaints. The first result highlights the need for IEQ investigations beyond office buildings. The second result strengthens the potential detrimental effect that uncomfortable IEQ conditions can have on job satisfaction. This study demonstrates the potential of User-Generated Content and text-mining techniques to analyze the IEQ of workplaces as an alternative to conventional surveys, for scientific and practical purposes.

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.