A field study of the thermal environment in residential buildings in Harbin

This paper presents the main findings of Project HIT.2000.25 supported by the Scientific Research Foundation of Harbin Institute of Technology, a field study of indoor climates and occupant comfort in 66 residential buildings in Harbin, located in northeastern China. One hundred and twenty sets of questionnaire responses were provided from 120 subjects for winter, each accompanied by a full set of physical indoor climatic measurements with an indoor climate analyzer and a thermal comfort meter, which met ASHRAE Standard 55-1992 and ISO Standard 7726 (1985) for accuracy, duration of sample, and response time. Only 77.5% of the indoor measurements fell within the ASHRAE Standard 55-1992 and ISO Standard 7730 (1994) winter comfort zone of 16.5∼22.5°C (corresponding to the average clothing 1.37 clo); 91.7% of the occupants considered their thermal conditions acceptable. The operative temperature corresponding to the accepted thermal environment by 80% of the occupants is 18.0∼25.5°C. Thermal neutrality, according to responses on the ASHRAE seven-point sensation scale, occurred at 21.5°C in winter. The preferred temperature is 21.9°C. Over 80% of the occupants felt dry at a relative humidity of 20%∼30% in the comfort zone and over 40% at a relative humidity of 30%∼55%.