Field Study On Human Thermal Adaptation At Residential And Office Buildings In Severe Cold Area

The winter in the severe cold zone is always long and cold. During the long heatingperiod, the outdoor climate keeps changing, while the indoor air temperature is keptstable. Based on the adaption theory, human thermal adaptation results in changingthermal neutral temperature in variable climates. How do the outdoor climate andindoor heating temperature influence on the human thermal comfort and adaptation?The objective of this study is to study the influence of outdoor climate and indoorthermal environment on human thermal comfort and thermal adaptation in residentialand office buildings in severe cold zone. We focus on the indoor thermal environmentcharacteristics and human thermal comfort and thermal adaptation during the heatingperiod and the trasition seasons before and after the heating period. Combined field testwith subjective questionnaires, we conducted a9-month continual investigation in10apartments in9residential buildings of5communities and19offices in6officebuildings.20residents and24office occupants were chosen as subjects.The results show that both the average indoor air temperatures in the residentialhouses and the office buildings were close to or beyond the upper limit recommended inthe thermal comfort standards. The relative humidities and air velocities were in thecomfort zone.During the heating period, over20%of the subjects in residential and office buildingsfelt “warm” or “hot”, which indicates there were overheat in both two kinds of thermalenvironment.The results showed that the indoor air temperature and operative temperature wereclose in both the residential and office buildings, so we used the indoor air temperatureto evaluate the indoor thermal environments. In addition, we suggest using the meanindoor air temperature of the past7days to evaluate the human thermal comfort in thesetwo environments.During the heating period, the thermal neutral temperature o f subjects in bothresidential houses and offices were lower than the average indoor temperature, and theranges of the acceptable temperature became wider. This approves that human can adaptto variable indoor and outdoor climates in order to establish their thermal comfort. Thethermal adaption models of the residential and office buildings in severe cold zoneswere established. During the heating period, over30%of the residents and40%of office occupantswould open the window to lower the indoor temperature. The subjects’ clothinginsulations in both residential and office buildings were related to the indoortemperature. These are the evidences of human thermal adaptation by behavioraladjustments.The indoor air temperature in residential houses kept increasing recent years and thethe residents’ thermal neutral temperature became higher, this brought out the increaseof the energy consumption for heating. The clothing insulation of the office occupantswas obviously higher than that of the residents, which indicates that the indoortemperature can be decreased when subjects adjust behaviors such as putting on moreclothes. It will be more comfortable and energy saving.Above all, the indoor temperature was too high during the heating period in bothresidential and office buildings, which would lead to thermal discomfort and waste ofenergy. We shoul make full use of human thermal adaptation, and properly lower theheating temperature in order to make a more healthy, comfortable, enegy saving, andsustainable development of thermal environment design with lowest energyconsumption.