Comparison of indoor air quality and thermal comfort standards and variations in exceedance for school buildings

Addressing indoor air quality (IAQ) and thermal comfort issues in school buildings is challenging but relevant. Firstly, their primary occupants are more vulnerable than adults. Secondly, school buildings are often inadequate being too old or designed to prioritise energy-efficiency targets. Thirdly, occupants have often little control over the indoor environmental quality (IEQ). Lastly, the SARS-CoV-2 pandemic highlighted the complexity and vulnerability of existing decision-making processes in relation to making timely and well-informed decisions about IEQ threats. Standards and guidelines vary over time and among similar countries despite targeting similar occupants, evaluate IAQ and thermal comfort independently, and do not include any specific adaptations to children. Thus, the aim of this research is to compare different available standards to evaluate IAQ and thermal comfort in school buildings. By analysing with different standards (EN16798, BB101, and ASHRAE 55 and 62.1) the data collected in schools in northern Italy, this research evaluated the consequences of different limits and approaches, and proposed improvements. The conclusions are that (i) thresholds and methods inconsistency within the same standard should be avoided;(ii) upper- and lower-bounded operative temperature scales are the most appropriate means to design and verify thermal comfort in classrooms;(iii) IAQ metrics that give an upper limit per a certain amount of consecutive time might prevent the build-up of indoor pollutants, even with high emissions from the building fabric;(iv) no standard proposes a combined IAQ and thermal comfort analysis which could enable more informed trade-off decisions considering IAQ, thermal comfort, and energy targets. © 2023 The Authors

Comparison of adaptive thermal comfort with face masks in library building in Guangzhou, China

During the COVID-19 pandemic, wearing masks in public spaces has become a protective strategy. Field tests and questionnaire surveys were carried out at a university library in Guangzhou, China, during June 2021 and January 2022. The indoor environmental parameters were observed, thermal sensation votes of students on various environmental parameters were collected, symptoms of students wearing masks were quantified, and the appropriate amount of time to wear masks was established. To identify acceptable and comfortable temperature ranges, the relationship between thermal sensation and thermal index was investigated. During summer and winter, people wearing masks are symptomatic for a certain duration. The most frequently voted symptom was facial heat (62.7 % and 54.6 % during summer and winter, respectively), followed by dyspnea. During summer, more than 80 % of the participants subjects were uncomfortable and showed some symptoms after wearing masks for more than 2 h (3 h during winter). In the summer air conditioning environment in Guangzhou, the neutral Top was 26.4 °C, and the comfortable Top range was 25.1–27.7 °C. Under the natural ventilation environment in winter, the neutral Top was 20.5 °C, and the comfortable Top range was 18.5–22.5 °C. This study may provide guidance for indoor office work and learning to wear masks in Guangzhou. © 2022 Elsevier Ltd

Comparison of adaptive thermal comfort with face masks in library building in Guangzhou, China

During the COVID-19 pandemic, wearing masks in public spaces has become a protective strategy. Field tests and questionnaire surveys were carried out at a university library in Guangzhou, China, during June 2021 and January 2022. The indoor environmental parameters were observed, thermal sensation votes of students on various environmental parameters were collected, symptoms of students wearing masks were quantified, and the appropriate amount of time to wear masks was established. To identify acceptable and comfortable temperature ranges, the relationship between thermal sensation and thermal index was investigated. During summer and winter, people wearing masks are symptomatic for a certain duration. The most frequently voted symptom was facial heat (62.7% and 54.6% during summer and winter, respectively), followed by dyspnea. During summer, more than 80% of the participants subjects were uncomfortable and showed some symptoms after wearing masks for more than 2 h (3 h during winter). In the summer air conditioning environment in Guangzhou, the neutral Top was 26.4 °C, and the comfortable Top range was 25.1–27.7 °C. Under the natural ventilation environment in winter, the neutral Top was 20.5 °C, and the comfortable Top range was 18.5–22.5 °C. This study may provide guidance for indoor office work and learning to wear masks in Guangzhou.

Indoor thermal comfort in a rural dwelling in southwest China.

Recently, indoor thermal comfort has received more scholarly attention than ever due to the COVID-19 pandemic and global warming. However, most studies on indoor thermal comfort in China concentrated on urban buildings in the east and north. The indoor thermal comfort of rural dwellers in southwest China is insufficiently investigated. Hence, this study assesses residents' indoor thermal comfort in a rural dwelling in Linshui, obtains the thermal neutral temperature of the rural area, and analyzes the thermal adaptation behavior of rural dwellers. The results reveal that the thermal neutral temperature of rural dwellers is 29.33°C (operative temperature), higher than that presented in previous studies based on the same climate region. Indoor thermal conditions in rural dwellings are relatively harsh, but various thermal adaptation behavior of rural dwellers significantly improve their ability to withstand the harsh conditions. When people live in an environment with a (relatively) constant climate parameter (e.g., humidity), their perception of that parameter seems compromised. Most rural dwellers are unwilling to use cooling equipment with high energy consumption. Therefore, more passive cooling measures are recommended in the design and renovation of rural dwellings.

Investigation of the effects of face masks on thermal comfort in Guangzhou, China.

Wearing masks to study and work places has become a daily protective measure during the COVID-19 pandemic. In the summer of 2021, environmental parameters were monitored, and students in a university library in Guangzhou, China, were surveyed to analyze the possible symptoms of wearing masks for a long time, and to assess the sensitivity of various body parts to the environmental parameters. Concurrently, the preference of subjects wearing masks for various environmental parameters was also analyzed. Additionally, the relationship between thermal sensation and thermal index was analyzed to identify acceptable and comfortable temperature ranges. The expected duration of wearing masks was counted. Subjects wearing masks had greater requirements for environmental comfort, and reported increased thermal discomfort of the face and head, compared to those without masks. More than 70% of the subjects wearing masks reported that they experienced discomfort on their faces. Among the subjects who experienced discomfort, 62.7% reported that facial fever was the main symptom; while some reported symptoms of dyspnea (25.4%) and rapid heartbeat (9.1%). More than 75% of the subjects were expected to wear masks for 2.0 h or less. Evaluation of environmental thermal sensation, including overall, facial, and head thermal sensation, differed among subjects who wore and did not wear masks. The indexes of neutral Operative temperature/Standard Effective Temperature (T op /SET*) and preferred T op /SET* were lower among subjects with masks than among those without masks. The neutral T op /SET* deviation was 0.3 °C, and the preferred T op /SET* deviation was 0.5 °C. Additionally, the acceptable and comfortable temperature zones differed between the two cases. The subjects who wore masks preferred colder temperatures. These findings indicated that the environmental parameters should be adjusted to improve the thermal comfort of the human body while wearing masks in work or study places.