ABSTRACT
There is a growing concern about Indoor Environmental Quality (IEQ) in buildings as humans are spending longer in indoor environments, whether this is associated or not with climate change and vulnerability to extreme weather events. In the wake of the COVID pandemic, the need for indoor air quality control is likely to increase, the result of many adaptations in home environments to switch to remote work. In hot countries in the Global South, one of the alternatives is split A/C units with limited air renewal. While, odorless and colorless CO2, commonly generated by occupants through respiration, is among the relevant indoor air pollutants. The purpose of this study is to evaluate a low-cost, responsive air-renewal system in a climate chamber equipped with a standard split A/C unit. The results show the system's feasibility in curbing IAQ concerns and also highlight the risk of negative impacts on indoor thermal conditions and on energy consumption on using A/C. © 2023, The Author(s), under exclusive license to Springer Nature Switzerland AG.
ABSTRACT
Due to the inherent limitations of underground spaces, such as the lack of natural ventilation and sunlight, underground space users tend to face more health risks compared with their aboveground counterparts. However, little is known about how the underground environment, users' health, and their associations were impacted by the outbreak of the pandemic. In this study, we investigated and compared the impacts of the general underground environment on regular users' physical and psychological health before and after the pandemic. To achieve this aim, the data from 525 surveys were collected from eleven underground sites, followed by an objective field measurement study conducted at five underground sites in Hong Kong pre- and post-outbreak of the pandemic. The multigroup structural equation modelling results indicated that: (i) surprisingly, the users' satisfaction towards almost all underground environment factors, including greenery, connectivity with the aboveground environment, thermal comfort, ventilation, indoor air quality, acoustic comfort, and lighting, excluding wayfinding, were significantly higher in the post-outbreak period;(ii) the users' health, both physical and psychological, was significantly better in the post-outbreak period;(iii) the impacts of visual comfort on the users' physical and psychological health were significantly greater in the post-outbreak period (critical difference ratio (;CDR;) > 1.96);(iv) the impacts of wayfinding, greenery, and acoustic and thermal comfort on the users' physical or psychological health were significant only in the pre-outbreak period (;CDR;> 1.96);(v) the impacts of connectivity on the users' physical and psychological health were significant in both the pre- and post-outbreak periods (;CDR;< 1.96). The findings were further cross-validated using the objective measurement results. With an increasing need to develop healthy underground spaces, the study contributes to the development, design, and management of the underground environment to enhance the users' health in the post-outbreak era.
ABSTRACT
It is now widely recognised that aerosol transport is major vector for transmission of diseases such as COVID-19, and quantification of aerosol transport in the built environment is critical to risk analysis and management. Understanding the effects of door motion and human movement on the dispersion of virus-laden aerosols under pressure-equilibrium conditions is of great significance to the evaluation of infection risks and development of mitigation strategies. This study uses novel numerical simulation techniques to quantify the impact of these motions upon aerosol transport and provides valuable insights into the wake dynamics of swinging doors and human movement. The results show that the wake flow of an opening swinging door delays aerosol escape, while that of a person walking out entrains aerosol out of the room. Aerosol escape caused by door motion mainly happens during the closing sequence which pushes the aerosols out. Parametric studies show that while an increased door swinging speed or human movement speed can enhance air exchange across the doorway, the cumulative aerosol exchange across the doorway is not clearly affected by the speeds.
ABSTRACT
Novel coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus-2 (SARS-COV-2) is spreading rapidly around the world and has become a global pandemic. Meteorological factors have been recognized as one of the critical factors that influence the epidemiology and transmission of infectious diseases. In this context, the World Meteorological Organization and scholars at home and abroad have paid extensive attention to the relationships of environment and meteorology with COVID-19. This paper systematically collected and sorted out relevant domestic and foreign studies, and reviewed the latest research progress on the impact of environmental and meteorological factors on COVID-19, classifying them into typical meteorological factors (such as temperature, humidity, and wind speed), local environmental factors (such as indoor enclosed environment, ventilation, disinfection, and air conditioning), and air pollution. Current research evidence suggests that typical meteorological factors, local environmental factors, and air pollutants are closely related to the transmission of COVID-19. However, the results of different studies are still divergent due to uncertainty about the influencing mechanism, and differences in research areas and methods. This review elucidated the importance of environmental and meteorological factors to the spread of COVID-19, and provided useful implications for the control of further large-scale transmission of COVID-19 and the development of prevention and control strategies under different environmental and meteorological conditions.Copyright © 2022, Shanghai Municipal Center for Disease Control and Prevention. All rights reserved.
ABSTRACT
The SARS-CoV-2 virus and its variants and COVID-19 disease have affected every aspect of society. The US National Academy of Sciences has been providing scientific insights and advice to aid policymakers and researchers in their quest to respond to the pandemic. Since 2020, it has produced numerous reports and workshop proceedings intended to integrate science into national preparedness and response decision-making, to explore lessons learned and best practices from previous preparedness and response efforts, and to consider strategies for addressing misinformation (NASEM, 2021). Among these was a 2021 symposium series that analyzed engineering's role in catalyzing COVID-19 response, recovery, and resilience, examining topics including the mitigation of exposure in public transit systems, engineering solutions to managing pathogens indoors, and the factors influence the transmission of infectious diseases in cities. Speaker presentations addressing these indoor environment topics are summarized here. © 2022 17th International Conference on Indoor Air Quality and Climate, INDOOR AIR 2022. All rights reserved.
ABSTRACT
A method for determining the presence of SARS-CoV-2 RNA in HEPA filters from portable air cleaners (PACs) have been developed and validated. Herein, a monitoring survey was conducted for 13 weeks in three indoor environments, school, nursery and a household of a socio-sanitary center in Ciudad Real, Spain. In this study, we employed environmental monitoring by RT-PCR of the presence of SARS-CoV-2 in HEPA filters and other surfaces of these indoor spaces for a selective screening in asymptomatic population groups. The aim was to limit outbreaks in an early stage. Only one HEPA filter tested positive in the socio-sanitary center. After analysis by RT-PCR of SARS-CoV-2 in residents and healthcare workers, one worker tested positive. Therefore, this study provides direct evidence of virus-containing aerosols trapped in HEPA filters and the possibility of using these PACs for environmental monitoring of SARS-CoV-2 while they remove airborne aerosols and trap the virus. © 2022 17th International Conference on Indoor Air Quality and Climate, INDOOR AIR 2022. All rights reserved.
ABSTRACT
The COVID-19 pandemic has highlighted the importance of indoor air quality (IAQ) since SARS-CoV-2 may be transmitted through virus-laden aerosols in poorly ventilated spaces. Multiple air cleaning technologies have been developed to mitigate airborne transmission risk and improve IAQ. In-duct bipolar ionization technology is an air cleaning technology that can generate ions for inactivating airborne pathogens and increasing particle deposition and removal while without significant byproducts generated. Many commercial in-duct ionization systems have been developed but their practical performance on pollutant removal and potential formation of byproducts have not been investigated comprehensively. The results in this study showed that the in-duct bipolar ionization technology can significantly improve the particle removal efficiency of the regular filter, while no significant ozone and ion were released to the indoor air. © 2022 17th International Conference on Indoor Air Quality and Climate, INDOOR AIR 2022. All rights reserved.
ABSTRACT
In the context of the Corona pandemic the investigation of aerosol spreading is utmost important as the virus is transported by the aerosol particles exhaled by an infected person. Thus, a new aerosol generation and detection system is set up and validated. The system consists of an aerosol source generating a particle size distribution mimicking typical human exhalation with particles sizes between 0.3-2.5 µm and an array of Sensirion SPS30 particulate matter sensors. An accuracy assessment of the SPS30 sensors is conducted using a TSI OPS3330, a high-precision optical particle sizer. Low deviations of ±5 % of the particle concentration measured with the SPS30 with respect to the OPS are reported for concentrations below 2'500/cm3 and +10% for particle densities up to 25'000/cm3. As an application example the system is employed in a short distance single-aisle research aircraft Dornier 728 (Do728) located at DLR Göttingen, to investigate the large-scale aerosol-spreading. With this measurement system spreading distance from an index passenger extending one seat row to the front and two seat rows to the back is determined. © 2022 17th International Conference on Indoor Air Quality and Climate, INDOOR AIR 2022. All rights reserved.
ABSTRACT
Owing to the COVID-19 pandemic, many companies have introduced working from home to avoid the risk of infection. In this study, we conducted questionnaire surveys and analysed the building energy management system (BEMS) in an office building where the number of employees working from home increased after the onset of the pandemic. The influence of working from home on the indoor environment satisfaction and the variability in energy consumption at home and office was determined. The indoor environment satisfaction was significantly higher when working from home than when working at the office. In 2020, the total energy consumption at home and office decreased by 30% in April and increased by 22% in August compared to the previous year. To work from home while saving energy regardless of the season, it is necessary to reduce office energy consumption by decreasing the number of workers present at the office. © 2022 17th International Conference on Indoor Air Quality and Climate, INDOOR AIR 2022. All rights reserved.
ABSTRACT
The importance of indoor air quality (IAQ) to reduce infectious disease transmission has become clear during the COVID-19 pandemic. In addition to SARS-CoV-2, other diseases, including RSV and influenza, are spread by airborne transmission, and often indoors-where most people spend over 90% of their lives. Given the importance of indoor environments in the spread of infectious disease, ventilation and filtration to improve IAQ should play a major role in preparing for a global catastrophic biological risk event (GCBR). This study involves performing a review of peer-reviewed literature and reports about improving indoor air quality in public spaces and interviewing technical experts in the fields of indoor air, building ownership, IAQ policy, and disease transmission control. The goal of the study is to identify and develop near and long-term policy actions for improving IAQ aimed to reduce GCBRs and other infectious diseases at various levels, including local and national. © 2022 17th International Conference on Indoor Air Quality and Climate, INDOOR AIR 2022. All rights reserved.
ABSTRACT
From the early stages of the COVID-19 outbreak, there have been many reports on cluster infections in clubs and bars. Meanwhile, there is no report on the indoor air environment in those places and it will limit measures for infection control. This study aims to understand the indoor air and ventilation environment and to propose practical and appropriate improvement measures for related industries. In addition to measuring CO2 concentration in clubs and bars in Tokyo, we have surveyed the voluntary measures taken against COVID-19, outlines of building and ventilation/air conditioning equipment, ventilation regime, and so on. © 2023 Architectural Institute of Japan. All rights reserved.
ABSTRACT
Indoor environment has significant impacts on human health as people spend 90% of their time indoors. The COVID-19 pandemic and the increased public health awareness have further elevated the urgency for cultivating and maintaining a healthy indoor environment. The advancement in emerging digital twin technologies including building information modeling (BIM), Internet of Things (IoT), data analytics, and smart control have led to new opportunities for building design and operation. Despite the numerous studies on developing methods for creating digital twins and enabling new functionalities and services in smart building management, very few have focused on the health of indoor environment. There is a critical need for understanding and envisaging how digital twin paradigms can be geared towards healthy indoor environment. Therefore, this study reviews the techniques for developing digital twins and discusses how the techniques can be customized to contribute to public health. Specifically, the current applications of BIM, IoT sensing, data analytics, and smart building control technologies for building digital twins are reviewed, and the knowledge gaps and limitations are discussed to guide future research for improving environmental and occupant health. Moreover, this paper elaborates a vision for future research on integrated digital twins for a healthy indoor environment with special considerations of the above four emerging techniques and issues. This review contributes to the body of knowledge by advocating for the consideration of health in digital twin modeling and smart building services and presenting the research roadmap for digital twin-enabled healthy indoor environment.
ABSTRACT
Droplet nuclei dispersion patterns in indoor environments are reviewed from a physics view to explore the possibility of airborne transmission of SARS-CoV-2. This review analyzes works on particle dispersion patterns and their concentration in vortical structures in different indoor environments. Numerical simulations and experiments reveal the formation of the buildings' recirculation zones and vortex flow regions by flow separation, airflow interaction around objects, internal dispersion of airflow, or thermal plume. These vortical structures showed high particle concentration because particles are trapped for long periods. Then a hypothesis is proposed to explain why some medical studies detect the presence of SARS-CoV-2 and others do not detect the virus. The hypothesis proposes that airborne transmission is possible if virus-laden droplet nuclei are trapped in vortical structures associated with recirculation zones. This hypothesis is reinforced by a numerical study in a restaurant that presented possible evidence of airborne transmission by a large recirculating air zone. Furthermore, a medical study in a hospital is discussed from a physical view for identifying the formation of recirculation zones and their relation with positive tests for viruses. The observations show air sampling site located in this vortical structure is positive for the SARS-CoV-2 RNA. Therefore, the formation of vortical structures associated with recirculation zones should be avoided to minimize the possibility of airborne transmission. This work tries to understand the complex phenomenon of airborne transmission as a way in the prevention of transmission of infectious diseases.
ABSTRACT
COVID-19 opened a window of opportunity to change the green development of the hospitality industry. For many years, Chinese tourists have been the world's largest source of outbound tourists. Therefore, this study attempted to improve built-environment strategies for green rooms at B&Bs using the empirical statistics of Chinese tourists after the end of COVID-19 control measures and different green B&B standards, combining IPA (importance-performance analysis). For the lack of a green built-environment study from a tourism perspective, this study can be used mainly for improving the green satisfaction of urban B&Bs as it attempted to fill the gaps in research on green B&B rooms. This study will significantly help improve the quality of green rooms for the B&B industry in the future, and it also provides an improved green B&B room sample for other countries and regions. Moreover, it is an optimistic attempt at hospitality and tourism recovery. © 2023 by the authors.
ABSTRACT
The Covid-19 outbreak has resulted in new patterns of home occupancy, the implications of which for indoor air quality (IAQ) and energy use are not well-known. In this context, the present study investigates 8 flats in London to uncover if during a lockdown, (a) IAQ in the monitored flats deteriorated, (b) the patterns of window operation by occupants changed, and (c) more effective ventilation patterns could enhance IAQ without significant increases in heating energy demand. To this end, one-year's worth of monitored data on indoor and outdoor environment along with occupant use of windows has been used to analyse the impact of lockdown on IAQ. Moreover, using on-site CO2 data, monitored occupancy and operation of windows, the team has calibrated a thermal performance model of one of the flats to investigate the implications of alternative ventilation strategies. The results suggest that despite the extended occupancy during lockdown, occupants relied less on natural ventilation, which led to significantly higher CO2 and PM10 concentrations. However, simple natural ventilation patterns or use of mechanical ventilation with heat recovery proves to be very effective to maintain acceptable IAQ. © International Building Performance Simulation Association, 2022
ABSTRACT
Most people spend 80-90% of their lives indoors. This makes controlling the airborne transmission of respiratory viruses such as influenza, rhinovirus, SARS, and COVID-19 in indoor environments important for healthy building outcomes. Though direct transmission from droplets and surfaces is usually a more effective means of infection transfer, buildings need to operate assuming aerosol transmission can be a serious risk. This study used simulations to assess the impacts of occupant density and ventilation rates as control measures to reduce the risk of aerosol transmission of COVID-19 in large and small offices. The simulation outputs were selected to correspond with in situ CO2 sensors and control points. The results of the simulation can be used to set targets for CO2 and other parameters that can be measured by low-cost sensors to manage risk of infection due to aerosol transmission. © International Building Performance Simulation Association, 2022
ABSTRACT
Corona Virus (COVID-19) has already done havoc in the world. More than six hundred million people suffered from this virus and six million people are dead amongst them in the world. In Bangladesh, two million people have tested positive and approximately 30 thousand people are dead. SARS-CoV-2 virus causes this infectious corona disease. When an infected individual sneezes, coughs, speaks, or breathes, the virus is disseminated from their mouth or nose. One can also be infected by touching contaminated surface and spreads more in indoor environment. So, it has taught us the necessity of washing and sanitizing in our daily affairs. Automatic boot spray machine is a very practical and useful instrument to fight against the corona virus. This contact free spray machine helps to sanitize the boot without getting in contact with the surface and ultimately helps to prevent the spread of corona virus. The purpose of this essay is to create a boot sprayer that automatically releases soapy water. At a distance of meters, an obstruction sensor is employed to identify the heat and presence of the boot. A p-n-p transistor is used to operate the machine. This machine works perfectly at a distance of 2-30cm. It also provides good sensitivity percentage. This setup is user convenient and it saves money and power. © 2023 IEEE.
ABSTRACT
This article discusses about the design and deployment of a smart robotic system on university campuses for monitoring the indoor environment, health protocols, and sanitation. The designed VEX autonomous robotic system performed the following tasks: (a) moving around the university classrooms and scanning the body temperature of students and staff, as well as tracking environmental parameters in classrooms;(b) executing sanitation function by disinfecting objects in classrooms;and (c) performing security function by sending an alert signal to health and safety officer if a student or staff with fever enters the classroom, or if staff or student is not wearing face mask indoors. Particle Photon microcontrollers linked to sensors and actuators were used to detect and manage indoor environmental conditions as well as track individuals' body temperatures from a distance, with the data being stored in the ThingSpeak and Particle cloud platforms and displayed on smartphone apps. Transfer learning through MIT App Inventor's Personal Image Classifier was used to detect health protocol violations with 93.33% accuracy. The maximum distance traversed by the robot prototype was 38 meters, with an average time of 220 seconds and an average speed of 0.17 meters per second. The robot had an 88.89% success rate in following the black-lined course. This intelligent robotic system can limit staff and student exposure to infectious diseases and implement "new normal"health and safety practices on campus as post-COVID-19 precautions. © 2023 IEEE.
ABSTRACT
Quarantine is one of the effective approaches to control the spread of COVID-19. However, prolonged isolation may harm the health of residents, especially students, who are quarantined in dormitories. This study surveyed students' behaviors, living environment, and psychological state through an online questionnaire. The results showed that during the isolation period, the participants' discomfort mainly came from high temperatures, high humidity, loud sounds, and dark lighting. Moreover, about half of the students experienced severe anxiety or depression, with poor sleep and an unclear mind being the most common problems. Additionally, this study focused on exploring the correlations between environmental perceptions and the psychological state of isolated students, that were identified to be significant. Furthermore, as isolation time was prolonged, the psychological state of isolated students worsened, and the most significant factor changed from thermal sensations to acoustic sensations. Interestingly, the psychological state of males was worse than females, and they were more easily affected by their thermal and acoustic environments. Therefore, keeping the environment comfortable has a positive influence on maintaining the good psychological condition of people in isolation. This study can provide suggestions for the improvement of indoor environments and for the mental health of people in isolation and in other similar situations.