Comfort limit for cold radiation from cold walls and windows in winter

Local human thermal discomfort may exist because of cold radiation from a cold surface, such as a cold external wall or window with lower inner surface temperature in severe cold and cold zones in winter. In order to study the limit of cold surface temperature causing discomfort, analyses the human thermal responses under the most unfavorable cold radiant condition based on the experimental data of an artificial climate chamber. The results show that the calf of subjects is the most sensitive part to cold radiation of external walls and windows. Establishes a correlation model of the overall and local thermal sensations of the human body under the most unfavorable conditions. When the indoor air temperature is 19 ℃ and the subjects are 1 m away from an external wall and an external window, the average thermal sensation vote of 20 subjects is -0.82, which is the lower limit of 20% of dissatisfied percentage. The limit of the difference is 2.6 ℃ between the indoor air temperature and the inner surface temperature of the external wall and the external window under this condition.