Research On The Dynamics And Mechanism Of Human Thermal Adaptation In Building Environment

The goal of adaptive thermal comfort research is to achieve a good balance between reducing space conditioning energy consumption and improving occupants' comfort perception.This paper investigated the disputing issue of winter space heating and tried to figure out the thermal adaptation patterns of Chinese residents through questionnaire surveys.Climate chamber experiments were designed to clarify the underlying adaptive mechanisms from physical,physiological,psychological perspectives,which provides the basis for establishing a more reasonable adaptive thermal comfort model.The main contents are as follows:Firstly,large-scale online questionnaire surveys were carried out in different space heating zones to explore the thermal adaptaion laws of Chinese residents.The results show that residents' s thermal adaptation was significantly affected by their indoor thermal history,and residents' comfort evaluations of indoor thermal environment were usually amplified during the comparision between different thermal experiences.When describing the dynamics of the residents' demand for thermal environment,it is found that the demand factor is easy to upgrade while different to decline.Secondly,thermal comfort field surveys were conducted in real buildings in both Shanghai and Beijing to verify the dynamics of human thermal adaptation.The results show that the demand factor could be applied to describe human thermal adaptation dynamics but the difficulties of different adaptation directions were asymmetric.It is suggested that the dynamics of human thermal adaption should be fully considered in practice to avoid sudden changes during the space heating season.Thirdly,physiological experiments were conducted in climate chamber to figure out the influence and mechanism of physiological acclimatization from three levels: whether there is influence? how much is the effect? how to describe? The results show that physiological adaptation can be revealed from two dimensions: short-term aspect and long-term aspect.While the short-term physiological adaptation can be described by human body metabolic regulation laws,the long-term acclimatization can be described by indexes like adaptation factor and weighting factor.Fourthly,psychological experiments were conducted in climate chamber to explore the mechanism of psychological adaptation from three levels: whether there is influence? how much is the influence? how to describe? The results show that the impact of environmental comfort approaches includes perceived control and physical envionrment improvement,in which perceived control is a psychological way to improve occupants' thermal comfort perception and its effect can be simply quantified.Finally,a new adaptive heat balance model was established by quantifying the effects of different adaptation layers like behavioral regulation,physiologic acclimatization,psychological adaptation and physical improvement.The new model inherited the computational advantages of the PMV and the empirical advantages of adaptive thermal comfort model,which makes it have flexible applicability in practical application.These findings are useful to reveal the mechanism of human thermal adaptation in buildings and building new adaptive thermal comfort models.The conclusions of this study can serve as references for the development of China's building thermal environment evaluation criteria.