Information on airconditioning and ventilation has been continuously disseminated in response to the Japanese Government's announcement of the need for appropriate ventilation measures against the new coronavirus disease (COVID-19), and the issuing of an emergency presidential discourse by the presidents of Engineering Societies. In this paper, we add to the information the latest knowledge on the behavior of SARS-CoV-2 in air, describe its diffusion characteristics in the built environment, and summarize the effects of temperature and humidity on the virus. Then we recommend varying approaches of airconditioning control for facility type.

The nonconformity rates of indoor environment in specific buildings were investigated using local government surveys and the following results were got. The nonconformity rates of temperature, humidity and carbon dioxide concentration have been increasing since 1998. The factors in carbon dioxide concentration were analyzed in consideration of the increase of ambient concentrations, the frequency of indoor concentrations and the change of the survey methods. The nonconformity rate of carbon dioxide concentration became 3.1% higher because of the increase of ambient concentration, 7.2% higher because of the ventilation reduction and 11.6% higher according to survey methods in these nineteen years.

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Based on the measurement of the moisture content in the stratum corneum, the transient model of the moisture transfer in skin was proposed with using the simultaneous heat and moisture transfer equations for hygroscopic range. For the modeling, the simultaneous heat and moisture transfer equation for the hygroscopic range was adapted for the stratum corneum with the thickness of 30μm, considering the contact with the ambient air, and the skin moisture content at the depth of 30μm given as saturated. As the results, the distribution of moisture content calculated by using the proposed analytical model agreed with the measured results, by taking into account the dependence of the moisture conductivity on the moisture content. It was suggested that the proposed model could explain the transient response of skin surface moisture distribution to the change in indoor humidity. Keywords :