The Method To Predict Thermal Sensation Based On Physiological Acclimatization In Winter In Hot Summer And Cold Winter Climate Zone

The indoor therml environments are cold and badly-controled in winter in the Hot Summer and Cold Winter(HSCW)climate zone of China,which combined part-time,non-central and local heating systems with the naturally ventilation systems.The occupants in this area are physiological acclimatized to the history of cold exposure in certain degree.Thus,it is important for the reasonable regulation of heating system to know how to accuractely evaluate the indoor thermal comfort under such situation.The PMV(Predicted Mean Vote)index is not suitable for predicting themal sensation of coldadapted occupants,and the adaptive thermal comfort model was used for free-running or naturally ventilated thermal enviroments.However,which thermal comfort model was suitable in the part-time and non-central heating systems in the HSCW climate zone was unclear.Thus,this study aims to reveal the features of cold acclimation in winter in the HSCW climate zone,by field investigation and experiments in climate chamber,and provides the reference information and optimized thermal comfort models for demand side management of heating.To reveal the features of cold acclimation and its effects on TSV(Thermal Sensation Vote),field studies were conducted in residential and office buildings in HSCW climate zone.Results showed the adaptive thermal comfort model was suitable for the naturally ventilated buildings,and the PMV index was suitable for the warm environments in heated buildings However,when the occupants were cold-adapted with history of cold exposure,the exsited themal sensation indexes performed much worse in heated space.To analyze the dynamic rules of human thermal responses,two groups of total 32 subjects who have different indoor thermal histories were investigated in unstable thermal conditions.Results show the thermal sensation vote and heart rate of the cold-adapted(CA)group were significantly different from that of the warm-adapted(WA)group in some experiment periods.However,there were no difference in skin temperatures and blood pressure between the CA and WA groups during the whole experiment period in both conditions.These mean the heat loss and vasoconstriction were not but the thermogenesis of body was affected by thermal history.The quantified relationship between heart rate and metabolic rate was built and revised according to thermal history to be used for the dynamic thermal sensation prediction of occupants with different thermal history.To clarify the uneven distribution of skin temperature and its effect on heat loss under different winter clothing ensembles in HSCW climate zone,20 subjects were recruited and their local skin tempatures at head,chest,back,upper arms,forearms,hands,thighs,claves and feet were tested and recorded using high accuracy temperature sensors(±0.1?).The distribution of skin temperature was annalyzed and the new weighting formulas for mean skin temperature were proposed.The distribution rule of local heat transfer for a seated occupant was revealed,based on the optimized local insulation and actual skin temperature,which could be used as reference for local heating efficieny and optimization of thermal sensation model.The Ca PMV(Cold-adaptive Predicted Mean Vote)model was proposed to improve the accuracy of the traditional PMV model,based on the expereimental data and mechanism of physiological acclimation to cold.Based on the actual mean skin temperature in experiement series I,adjustment was made for the neutral skin temperature;Then,new weighting factors of air temperature at different heights were proposed based on the heat exchange efficiency of local human body at different heights;According to the mechanism of the effect of thermal history on thermogenesis,the coefficient to adjust metabolic rate was calculated based on the inversely determined metabolic rate.Validation study showed that the accuracy of Ca PMV value was improved,and could be applied in more actual building environments.The method to predict thermal sensation based on physiological acclimation proposed by this study could evaluate the various indoor thermal environments,which could provide the basis for the heating management in HSCW climate zone and the references for the prediction of thermal sensation in winter in different climate zone.