REVIEW AND ANALYSIS OF EXISTING METHODS TO ASSESS THE INDOOR ENVIRONMENTAL QUALITY (IEQ) FOR OFFICE BUILDINGS

Population in developed countries spend most of their time indoors, whether in their homes, workplaces, stores or leisure areas. Due to the COVID-19 pandemic, this situation worsened and now, more than ever, the importance of a high Indoor Environmental Quality (IEQ) is highlighted. The IEQ is very important in building performance since it is directly related to its occupants' comfort, health, wellbeing, and productivity and the Sick Building Syndrome (SBS) concept. Therefore, it is essential to develop tools to support designers' decision-making in the materialization of indoor environments with higher quality. From the state-of-art analysis, it is possible to conclude that the methods to assess the overall building performance already consider the IEQ. Still, most use an approach that does not cover all relevant indicators. In this context, this paper presents the first milestone of a research work that aims to develop a new method to rate the overall IEQ of office buildings in Portugal. The main objective of the present study is to propose a list of IEQ indicators for office buildings, adapted to the Portuguese context, based on the analysis of existing rating methods for buildings and the recommendations of national and international standards. © 2022 The Author(s). Licensed under a CC-BY 4.0 licence.

Natural ventilation as a healthy habit during the first wave of the COVID-19 pandemic: An analysis of the frequency of window opening in Spanish homes

Since SARS-CoV-2 spread worldwide in early 2020, many countries established lockdowns for protection. With a main transmission by aerosols, ventilation was promoted. This article analyses natural ventilation of Spanish housing during the spring 2020. An online questionnaire was launched, obtaining for this study 1502 responses. The comparative window opening before and during confinement, and households, dwellings and home activity variables, were analysed. The binary logistic regression model before pandemic indicated that ventilating properly related to: a worse perceived IAQ (OR = 1.56);thermal adaptation measures, especially those that prefer to open/close windows (OR = 1.45);not having heating system (OR = 1.15);and using power to heat water (OR = 1.60). For the confinement period, the model highlighted: being an employee (OR = 1.88);using heavy clothing in the home (OR = 2.36);and again, open/close windows for adaptation (OR = 2.24). According to specific tasks in quarantine, frequent ventilation was boosted by: an increasing use of oven (OR = 14.81);and alteration of work-habits (OR = 2.70), sport-habits (OR = 1.79), and outdoor-activities (OR = 1.60). Thus, an adequate natural ventilation pattern during the quarantine was linked to low environmental comfort in general, by virtue of indoor air quality. This is corroborated by less acoustic-thermal insulation, worse indicators of heating use, and the adaptive response to opening/closing windows when external temperature changed. © 2022 The Authors

Natural ventilation as a healthy habit during the first wave of the COVID-19 pandemic: An analysis of the frequency of window opening in Spanish homes

Since SARS-CoV-2 spread worldwide in early 2020, many countries established lockdowns for protection. With a main transmission by aerosols, ventilation was promoted. This article analyses natural ventilation of Spanish housing during the spring 2020. An online questionnaire was launched, obtaining for this study 1502 responses. The comparative window opening before and during confinement and households, dwellings and home activity variables, were analysed. The binary logistic regression model before pandemic, indicated that ventilating properly related to: a worse perceived IAQ (OR = 1.56);thermal adaptation measures, especially those that prefer to open/close windows (OR = 1.45);not having heating system (OR = 1.15);and using power to heat water (OR = 1.60). For the confinement period, the model highlighted: being an employee (OR = 1.88);using heavy clothing in the home (OR = 2.36);and again, open/close windows for adaptation (OR = 2.24). According to specific tasks in quarantine, frequent ventilation was boosted by: an increasing use of oven (OR = 14.81);and alteration of work-habits (OR = 2.70), sport-habits (OR = 1.79), and outdoor-activities (OR = 1.60). Thus, an adequate natural ventilation pattern during the quarantine linked to low environmental comfort in general, by virtue of indoor air quality. This is corroborated by less acoustic-thermal insulation, worse indicators of heating use, and the adaptive response to opening/closing windows when external temperature changed.

Dwelling in times of COVID-19: An analysis on habitability and environmental factors of Spanish housing

In the wake of the SARS-CoV-2 pandemic, promoted by the World Health Organization (WHO), governments urged people to stay at home. For this reason, practically all human activity took place inside the houses. The research question established if housing quality responded to people's needs in the context of confinement. Specifically, the purpose was to taxonomize the dwelling stock occupied by confined households during the first COVID-19 wave in Spain, as well as to deepen in features and subjective perceptions on Indoor Environmental Quality (IEQ). As an exploratory study, an online questionnaire was disseminated in the Spring of 2020, obtaining 1,673 valid responses. A descriptive statistical analysis included sociodemographic, territorial and housing variables, related to indoor environmental quality, the availability of outdoor spaces, and the prospects for changes in. Also, a logistic regression stablished multivariate relations for the dependent variable “general dwelling satisfaction”. The results associated urban habitat, tenancy regime, higher incomes, and fewer cohabitants, with worse perceived IEQ, and lack of own outdoor space. Same variables showed relations with people's desire for domestic changes. In conclusion, it is remarkable the determining role of housing design for dwellers’ satisfaction, especially in uncertain times like COVID-19 pandemic. This not only conditioned the different ways of inhabiting and occupying dwellings, but also the people's capacity to face lockdown. The built environment, the habitat, and households’ circumstances also influenced. The latter did on people's perception of their experience, and how they lived and expressed it. Additionally, resilient building design and renovation opportunities were identified. © 2022

Multi-objective integrated BES-CFD co-simulation approach towards pandemic proof buildings

COVID-19 has posed an extraordinary burden to those professionals responsible for properly operating and safely maintaining facilities throughout this disaster. Considering this global pandemic, the common spaces in buildings must be reconsidered to accommodate a future in-presence existence. Governments address human health and safety as the most vital considerations worldwide;thus, Heating, Ventilation, and Air Conditioning (HVAC) designs, airflow patterns, and temperature distribution must all be reconsidered to achieve such healthy circumstances. Based on this, a Building Energy Simulation-Computational Fluid Dynamics (BES-CFD) validated model has been analysed in terms of various HVAC designs. The simulations assessed the proposed solutions in terms of energy-saving, operational CO2 emissions, thermal comfort enhancement, and infection control. The results were closely examined and showed that the Underfloor Air Distribution (UFAD) system generates approximately laminar vertical airflow, reducing the likelihood of indoor infections and viral transmission. Supply air is delivered to the inhabitants’ zone without sacrificing mixing efficiency, ensuring long-term indoor environmental quality. Moreover, the UFAD model proved to be more cost-efficient compared to the Conventional Overhead Distribution (COHD) and has a lower carbon footprint and energy consumption. In terms of thermal comfort, the dynamic simulations showed a noticeable enhancement in PMV. Additionally, the UFAD provides a vertical temperature gradient profile that is sufficiently uniform. Moreover, the integrated DOAS-UFAD systems’ effectiveness was proved through a techno-economic analysis with a Return on Investment of 8.25% and a Payback period of 7.3 years.

Environmental conditions, mobile digital culture, mobile usability, knowledge of app in COVID-19 risk mitigation: A structural equation model analysis.

Introduction: The mobile digital culture (MDC) supports individual lives, communities, and real-time organizational surveillance during COVID-19 emergencies. Hence, the study examined the advancement in smart health devices evidence in smartphone apps technologies in surveillance, control, and tracking potential virus areas among high-risk populations. Objective: The study explored how environmental condition and MDC mediates between knowledge of App and mobile usability in the prevention of COVID-19 infection in high-risk areas. Methods: Using the concept of UTAUT, the study conceptualized that mobile usability, MDC, knowledge of App and environmental condition, are essential for COVID-19 mitigation. A cross-sectional method was adopted through an online survey to assess data from n = 459 mobile users. The association of the study models was appraised through structural equation models (Amos v.24.0). Result: We found mobile usability, knowledge of App, and MDC were statistically significant to COVID-19 mitigation. Environment condition as mediator had no effect in the study models. However, moderating effect of MDC shows a negative influence on the association between COVID-19 mitigation and knowledge of apps. Conclusion: Future policies should consider the development of mHealth technology to improve end-user experience. Also, future policies should entail data privacy to reduce the infringement of data collected. This approach will lead to a confidential, high acceptance of usability of mHealth apps infectious disease prevention.

Study on residential environment and workers' personality traits on productivity while working from home.

Working from home has drawn more attention with the development of information and communications technology and the coronavirus disease 2019 pandemic. Although studies on working from home have been conducted in various academic fields, few have focused on residential environment and personality traits. In the present study, air temperature and humidity of the home workplace were measured and a questionnaire survey was conducted to understand the relationship between residential environment and personality traits and at-home work productivity. The results suggest that comprehensive productivity while working from home improved. However, when examining individual aspects of productivity, the productivity of information processing improved while that of knowledge processing and knowledge creation deteriorated. The results also suggest the importance of improving the residential environment when working from home because productivity while working from home rather than from the office improved with high evaluation of the residential environment. Moreover, productivity decreased for workers with high neuroticism and increased for those with high openness or perseverance and passion, suggesting that some personality traits are more or less suitable for working from home. To improve the productivity of all workers, these findings have practical implications for promoting appropriate maintenance of the residential environment and introducing flexible work styles that account for personality traits.

Covid-19 Pandemic: Strategies to Improve Daylighting and Visual Comfort for Building Occupants

Sufficient lighting has a substantial impact on the health, comfort, and performance of building occupants. Researchers frequently focus on daylighting for its psychological, physiological, and economic benefits to human well-being. However, the COVID-19 pandemic demonstrated that these wellness considerations are no longer optional features of a building, but rather a necessary component of providing a comfortable and healthy living environment. Everyone must adhere to the stay-at-home order to mitigate pandemic transmission. This study aims to review the literature and recommends strategies that will improve building occupants’ daylighting and visual comfort. For the review, this study identified 41 peer-reviewed journal articles using a keyword search followed by a filter based on SCOPUS and Web of Science inclusion criteria. However, once the inclusion and exclusion criteria were applied, only 31 papers were chosen for evaluation. Thematic analysis of these 31 publications revealed eight tentative criteria for effective daylighting in buildings, categorised into three clusters: passive design, active design, and projected ideal daylighting based on daylight simulation tests. The results demonstrate that a passive design strategy provides improved illumination and is a more cost-effective way to achieve appropriate daylight and visual comfort in a facility. Despite its limitations, the study recommends the hybrid technique of passive and active design as a helpful experimental tool for future research targeted to increase the interior environment’s quality. © 2022, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

Cost-Effective Customizable Indoor Environmental Quality Monitoring System

Poor indoor environmental quality (IEQ) has become a global concern for World Health Organization (WHO),and its impact on health and well-being has been exacerbated by the COVID-19 pandemic. To monitor and sanitizeindoor air, this study develops a cost-effective and customizable IEQ monitoring system to detect unhealthy andlow-comfort air levels. This system uses ThingSpeak (MATLAB), microcontrollers (Arduino Uno), and variouslow-cost sensors to measure indoor air quality (IAQ) and IEQ in terms of gas, particulate matter, temperature, soundlevel, and ultraviolet (UV) light. The presented system is validated with respect to temperature, relative humidity,and particulate matter by benchmarking against the Camfil air image sensor manufactured by Camfil AB, Stockholm,Sweden. The average error of temperature, relative humidity, and PM2.5 are 0.55%, 5.13%, and 3.45%, respectively © by the authors. Licensee TAETI, Taiwan. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY-NC) license (https://creativecommons.org/licenses/by-nc/4.0/).

Optimisation of thermal comfort and indoor air quality estimations applied to in-use buildings combining NSGA-III and XGBoost

Indoor environmental quality (IEQ) monitoring of in-use buildings has become essential in recent years due to the COVID-19 pandemic, as it significantly affects the well-being, health and productivity of building users. Nevertheless, knowing in real time the environmental conditions in large multi-zone areas is a difficult issue. Thus, the use of machine learning techniques to estimate indoor conditions has increased considerably. The aim of this paper is to present an interpolation model, based on an optimised extreme gradient boosting algorithm, to estimate every minute the indoor temperature, relative humidity and CO2 concentration inside buildings. These estimations are obtained without requiring permanent monitoring in the occupied zone. The optimisation, focused on finding the minimun number of monitoring devices needed to provide accurate interpolations, is performed using the multi-objective genetic algorithm NSGA-III. This methodology was applied in a research centre in the north-western Spain. The results show that the optimised or reduced model is capable of estimating indoor temperatures and relative humidity with relative errors below 6% and CO2 levels below 10%.

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.

Preferences for Indoor Environmental and Social Comfort of Outpatient Staff during the COVID-19 Pandemic, an Explanatory Study.

While the pressure on hospital workers keeps growing, they are generally more dissatisfied with their comfort than other occupants in hospitals or offices. To better understand the comfort of outpatient workers in hospitals, clusters for preferences and perceptions of the indoor environmental quality (IEQ) and social comfort were identified in a previous study before the outbreak of the coronavirus disease 2019 (COVID-19) pandemic. This qualitative study explains the outpatient workers' main preferences for comfort during the COVID-19 pandemic. Semi-structured interviews and photo-elicitation were used. Contextual changes due to the COVID-19 pandemic were included. The questions in the interviews were based on the characteristics of the profiles, corresponding with the clusters. The data were analyzed with content analysis according to the steps defined by Gioia. Seventeen outpatient workers who had been part of the previous study participated. For some outpatient workers differentiation of preferences was illogical due to interrelations and equal importance of the comfort aspects. The main changes in perceptions of comfort due to the pandemic were worries about the indoor air quality and impoverished interaction. Because the occupants' preferences for comfort can change over time, it was suggested that further development of occupant profiles needs to accommodate changes.

Indoors ventilation in times of confinement by SARS-CoV-2 epidemic: A comparative approach between Spain and Italy.

With the arrival of the SARS-CoV-2 coronavirus, the scientific academia, as well as policymakers, are striving to conceive solutions as an attempt to contain the spreading of contagion. Among the adopted measures, severe lockdown restrictions were issued to avoid the diffusion of the virus in an uncontrolled way through public spaces. It can be deduced from recent literature that the primary route of transmission is via aerosols, produced mainly in poorly ventilated interior areas where infected people spend a lot of time with other people. Concerning contagion rates, accumulated incidence or number of hospitalizations due to COVID-19, Spain, and Italy have reached very high levels. In this framework, a regression analysis to assess the feasibility of the indoor ventilation measures established in Spain and Italy, with respect to the European framework, is here presented. To this aim, ten cases of housing typology were and analyzed. The results show that the measures established in the applicable regulations to prevent and control the risk of contagion by aerosols are not adequate to guarantee a healthy environment indoors. The current Italian guidelines are more restrictive than in Spain, yet the ventilation levels are still insufficient in times of pandemic.