Effects Of Different Air Conditioning Terminal Modes On Human Thermal Response In Transitional Environment

In the environment of different air conditioning terminal forms,the dominant heat transfer mode between human body and the environment is different,which leads to different thermal comfort feelings.Understanding the thermal response of people in different air conditioning terminal environments can guide architects and operators to design and regulate the indoor thermal environment in a more reasonable way,so as to improve people’s satisfaction with the indoor thermal environment.There are many researches on the influence of indoor thermal environment on thermal comfort.But most of them are confined to steady-state conditions.In practical work and life,due to commuting and other demands,people’s thermal environment and motion state are often in dynamic change.Especially in summer,after high temperature outdoor commuting and other activities,people will gather a lot of heat in their bodies.After entering the room,the heat in their bodies often cannot be dissipated quickly,resulting in uncomfortable thermal feelings.Therefore,it is necessary to study the dynamic thermal response of human body after exercise,and to find a simple and easy way to improve the thermal state of such building users.In this study,climate chambers are set up to simulate the thermal environment of the three stages experienced by personnel in the process of passing through the building transition space and finally entering the office after high-temperature outdoor activities in summer.By controlling the use form of air conditioning terminal(radiant ceiling with floor terminal,radiant ceiling terminal,radiant floor terminal and convection air conditioning terminal)in office environment simulation climate room and the use form of fan(on and off)in transition space simulation climate room,the effect of air conditioning terminal form and air flow on the thermal response of people after exercise in high temperature environment is investigated by means of subjective questionnaire survey and physiological parameter measurement.It is found that the subjective thermal sensation,average skin temperature and pulse rate are improved in different degrees after exercise in high temperature environment.At the same time,the high subjective thermal response and physiological state still need some time to reduce in the sitting stage.In radiant ceiling with floor terminal、radiant ceiling terminal,radiant floor terminal and convection air conditioning terminal environment,need 6 minutes,8 minutes,8minutes and 15 minutes to reach the neutral thermal sensation,need 15 minutes,15 minutes,20 minutes and 25 minutes to achieve high efficient working condition.In addition,at any same time,the overall thermal sensation of subjects decreased successively,while the overall thermal comfort and subjective evaluation efficiency increased successively in the above air conditioning terminal environment,but there is no significant difference.Besides,by setting up and using a fan in the simulated transition space and maintaining an ambient air flow rate of about 0.8 m/s,the thermal sensation of a person staying in the transition space for 5 minutes is significantly reduced from 1.9(hot)to 0.8(slightly hot).In addition,in the subsequent sitting stage,in the end environment of each type of air conditioning,the subjects’ thermal sensation reached neutral within 6 minutes,and their working efficiency reach high within 15 minutes.Therefore,forced ventilation,such as fans,can be used in the transition space of the building to improve the air flow rate of the environment and optimize the thermal experience of people entering the transition space of the building after summer commuting,so as to accelerate the recovery speed of the thermal state and work efficiency of people entering the air-conditioned room.