A survey of clothing insulation for university students in Japan: Effect of clothing insulation distribution between the upper and lower body in the winter

Abstract

The clothing insulation is an important factor in the adaptation to thermal environment for occupants. With the exception of certain types of clothing, occupants' clothing is divided into upper and lower body, and it is important to focus the analysis on clothing of upper and lower body. The objective of this study was to determine the effect of the clothing insulation distribution between the upper and lower body in a cold environment. In this study, the analysis was carried out using field surveys and simulations. In the simulation, the sensible heat loss from the human body was analyzed using the JOS-2 model. A thermal environment survey and a subjective vote survey were conducted from October 2019 to January 2020 at a university in Nagano City, Nagano Prefecture, Japan. Nagano City is characterized by a humid subtropical climate (Cfa) according to the Köppen climate classification. During the survey period, the mean outdoor air temperature was 9.6 °C and the mean indoor operative temperature was 20.8 °C. The survey revealed that the occupants adjusted the clothing insulation for the total body by adjusting the clothing insulation for the upper body to the thermal environment. The simulation demonstrated that the sensible heat loss and mean skin temperature of the upper and lower body differed between the conditions in which the total body clothing insulation was uniformly distributed and those in which it was not.