Human Thermal Responses To Lateral Wall Radiant Asymmetry

Because of the low outdoor temperature in winter or high outdoor temperature in summer,the internal surface temperature of the external wall is often different from the indoor air temperature and other internal wall temperature,forming an asymmetric radiation indoor environment.Long-term exposure to asymmetric radiation can aversely affect human comfort and health.In this paper,the affects of the long-term asymmetric radiation environment caused by the cold radiation and heat radiation of the indoor sidewalls on the human body's thermal response in winter and summer were studied through the laboratory research,analyzing with the mathematical statistics method and the psychological and physiological theory.Forty-four healthy college students were chosen for the experiments.Among them,20 were tested in winter and 24 in summer.Each experiment went on for 3hours.The results showed that in the cold radiation environment caused by cold wall,the physiological and psychological thermal responses of the subjects were significantly affected by time.Overtime,the subjects'physiological and psychological thermal responses decreased gradually.There was a slight increase in blood pressure,but it was within the normal range.The physiological and psychological thermal reactions of the subjects are greatly affected by the distance from the wall.As the distance from the wall increases,the skin temperature,thermal sensation and thermal comfort voting values of the subjects will be all increase.In the local thermal reaction,the subjects had the lowest skin temperature in the legs and hands,the lowest thermal sensation in the legs and feet,and the difference in the skin temperature and thermal sensation on both sides of the body was significant.In the sidewall of thermal radiation environment,the subjects'mental thermal response is significantly affected by time.With the passage of time,thermal sensation gradually returned to neutral,thermal comfort and thermal acceptability slightly increased.There was no significant change in physiological thermal response.Design limits of interior surface temperature are achieved.To meet 80%thermal acceptable,the upper limit of temperature difference(?T_w)is 3?,which gave in the"Thermal design code for civil building"can be satisfied in winter.To meet 90%thermal acceptance,the upper limit of ?T_w is 1?(at 180 min,0.5 m) and 1.5?(at 180 min,2.0 m)in winter.To meet 80% thermal acceptance the upper limit of ?T_w is 9?,and the upper limit of ?T_w is 4.5? to meet 90% thermal acceptance in summer.Lateral asymmetry radiation environment was established by regression analysis of the human thermal sensation and thermal comfort evaluation model:with an acceptable degree of thermal comfort and thermal sensation prediction model,using the maximum thermal sensation difference between body parts to predict thermal acceptable degree of regression model,the overall thermal sensation and thermal comfort and local thermal sensation and thermal comfort of the multivariate regression model.The influence model of physiological to psychological thermal response:the regression model of the influence of skin temperature on thermal sensation and the regression model of the influence of heart rate on thermal sensation.