Comparison of Indoor Environment and Energy Consumption before and after Spread of COVID-19 in Schools in Japanese Cold-Climate Region

Abstract

A report released by the WHO indicates that aerosols from infected people are one of the major sources of the spread of COVID-19. Therefore, as the COVID-19 infection caused by the SARS-CoV-2 virus spreads, it has become necessary to reconsider the design and operation of buildings. Inside school buildings in cold regions, not only is it not easy to increase ventilation during the winter, but it may also be difficult for students to attend classes while wearing masks during the summer because such buildings are not equipped with air-conditioning systems. In short, school buildings in cold climates have more problems than those in warm climates. We report on the results of indoor environmental measurement using our developed CO2-concentration meters, a questionnaire survey on students’ feeling of being hot or cold (i.e., ‘thermal sensation’), and a comparison of energy consumption before and after the spread of COVID-19 infection in schools in Sapporo, Japan, a cold-climate area. The results indicate that (1) more than 70% of the students participated in window ventilation by the CO2 meter, and (2) a relatively good indoor environment was maintained through the efforts of teachers and students. However, we also found that (1) 90% of the students felt hot in summer and (2) 40% felt cold in winter, (3) energy efficiency worsened by 7% due to increased ventilation, and (4) air quality was not as clean as desired during the coldest months of the year. Therefore, investment in insulation and air conditioning systems for school buildings is needed.

Optimal Hybrid Ventilation Strategy to Assure Adequate Indoor Thermal Comfort and Air Quality in Educational Spaces under a Tropical Climate

“…Also, with this strategy, energy consumption increased 0.58% and decreased -0.18%, respectively. In this matter, [13] and [21] mentioned that the students, when opening windows, showed thermal discomfort in the applications they carried out, so this strategy, in addition to the condensation effects of opening windows with the mechanical equipment on, was discarded. Bayoumi [31] mentioned that some of the solutions to condensation include standing cooling pads or putting in drainage systems (in extreme cases).…”

One-year operation performance of a decentralised all-air HVAC system for a school room

“…In this regard, Korsavi et al [14] provided a comprehensive analysis of the predictors that influence operations on windows and external doors and their impact on indoor quality, comfort, and energy. Another study reported on the results of indoor environmental measurement for schools in Japan in a cold climate area, considering CO 2 concentration, thermal sensation (i.e., students' feeling of being hot or cold), and a comparison of energy consumption before and after the spread of COVID-19 infection [15]. In another work, Franceschini and Neves [16] addressed the knowledge gap on the modelling of occupant behaviour for naturally ventilated and mixed-mode school buildings.…”

Modeling of indoor thermal comfort in the intelligent building

“…And he showed that with the temperature increase the mean PMV increased from -0.73 to 0.9, for TSV it was from -2.21 to 0.53, additionally comparing PMV and TSV, the temperature difference was from 2 o C -3 o C. Very recently Boudier and Hoffmann [17] considered the influence of decentralized heating systems for obtaining thermal comfort. Much scientific effort is also aimed at combining the issue of thermal comfort with the energy efficiency of buildings -such as current papers such as the papers by Tori et al [18], Yoshida et al [19] or Budiavan et al [20] focused mostly on the energy saving potential in office, residential and educational buildings.…”