Thermal Sensation Prediction Of Human Body Under Transitional Environment Based On Environmental Parameters

With the improvements of people's living standards, thermal comfort requirements are becoming higher and higher. Air-conditioned environment of steady-state and uniform creates a comfortable living and learning space for people, but it often causes discomforts because of transitional environments and the step changes of environmental parameters in our daily life,Such as inside and outside of the air-conditioned room, between the interior and exterior transition, the transition between inside and outside the bathroom and so on. Research has shown that it not only can make people be comfortable in heat or cool environment, but also can greatly reduce the air conditioning energy consumption through a reasonable set of parameters of the transitional space environment. However, it is not clear for the law of human thermal response under the current transitional environment and there are no common resultssuch as PMV, effective temperature which are used in the steady-state environment. Therefore, it is particularly important to establish the relationship between human thermal response and environmental parameters under transitional environments, which has a great significance for comprehensively evaluating the effect of thermal environment on the thermal response and developing the theory of human thermal comfort.The paper made an exploratory research for the transition between the non-uniform environment and the background uniform environment under the stimulation of head by human thermal comfort experimental approach. Different conditions in summer and winter were analyzed to survey thermal sensations after the transition, by which the qualitative description of overall thermal sensation changes under transitional environments in summer and winter were given.Four major environmental parameters that effected thermal sensation include the air temperature in the background area, relative humidity,the air temperature and wind speed of the working station area. The partial correlation coeffecients of various parameters on overall thermal sensation were obtained by partial correlations, and the linear correlation size of various parameters on the overall thermal sensation was achived. The paper raised the concept of effective temperature of before and after transition to analyze the thermal sensation change, which simplified the number of environmental parameters. Effective temperature has a direct effect on thermal sensation after transition through the analysis. The paper established a model using least squares support vector machine principle between overall thermal sensation and effective temperature of background region, effective temperature of stimulate part, residence time in the hot and cold transition environments. By the analysis of model error, the results showed that in both of the hot and cold transitions, the number of samples whose error within(-0.3,0.3) was above 88%, and model prediction results could well match the actual value. The model was extended to calculate the confidence intervals of model predictions under confidence level of 95%, which can eliminate the impact of individual differences to some extent so that the model is more practical.The paper established the four-dimensional model diagram between overall thermal sensation and effective temperature of background region, effective temperature of stimulate part and residence time. The relationship between overall thermal sensation and effective temperature of background region, effective temperature of stimulate part, residence time was analyzed qualitatively, and the control range of environmental parameters were suggested for the neutral zone after the hot and cold transitions.