Thermal environment and thermal adaptation in residential buildings

Abstract

Purpose / Context - The winter in the severe cold area of China is long and cold, with a long heating period. In recent years, the indoor air temperature during heating in residential buildings kept increas-ing. In order to study the thermal comfort and adaptation in such an overheated environment, a field study was carried out in Harbin. Methodology / Approach - A tracking investigation was conducted during the heating period in 2013-2014. 10 apartments were selected from 9 buildings in 5 residential communities, with 20 par-ticipants. The indoor and outdoor air temperatures, as well as relative humidity were monitored con-tinuously, while the residents were interviewed on their thermal responses online every week. 308 valid questionnaires were collected. The heating periods were separated into three phases based on the outdoor temperature. Results - The results show that the mean indoor air temperatures in the early-, mid- and late-heating periods were 23.6°C, 24.3°C and 25.0°C, respectively, which were larger than or close to the upper limit recommended by thermal comfort standards, and slightly higher than the related thermal neutral temperatures. With the heating process, the mean clothing insulation of residents decreased. Open-ing windows and reducing clothing were mainly taken by the residents to adapt to the overheated environment. Key Findings / Implications - The neutral temperature rose with the mean air temperature increas-ing in the heating period. The lower limit of the temperature range in winter is to be suggested in heat-ing design to achieve a sustainable indoor environment. Originality - It was found that human thermal neutral temperatures in residential buildings changed with the indoor, and many evidences of thermal adaptation were got.