Experimental And Simulant Study On Thermal Comfort Of Workstation Radiant Heating Terminals

With the improvement of people's living standards,people are paying more and more attention to the comfort level of the indoor environment.Research shows that even though traditional air conditioners consume a lot of energy and create a relatively uniform indoor environment,it is difficult to meet the diverse comfort needs of people.Relatively speaking,non-uniform environments are more common,and personalized systems can meet people's comfort needs while reducing unnecessary energy consumption.In recent years,research on personal comfort systems has increased,and scholars have explored a variety of local cooling or heating methods to meet the individual needs of people.However,the types of systems are mostly based on the way of cooling or ventilation.There are few studies on heating,and the way in which personal systems combining task air conditioning and radiant heating affect the thermal sensation and thermal comfort of the human body is unclear.In the non-uniform environment,the stimulating response of local radiant heating to the human body and the trend of the human thermal sensation model are yet to be further studied.In this paper,the task air conditioning and radiant heating terminals were combined,and the thermal comfort of the workstation radiant heating terminals was studied experimentally.According to the experimental design,a total of 20 college students were invited to participate in series of experiments about thermal comfort(10 boys and 10 girls).This paper mainly studies the effects of different indoor ambient temperatures(14,16,18,20 °C)and different temperatures of radiant heating terminals(50,60 °C)on human thermal sensation and thermal comfort.A total of 10 experimental conditions were involved in the experiments.The subjective thermal responses of all subjects were collected by questionnaire during the test,including the overall thermal sensation,local thermal sensation,overall thermal comfort,local thermal comfort,thermal expectations and thermal acceptability.Other objective parameters in the experimental process were also monitored and collected using relevant instruments.Subsequently,the human thermal sensation models under this way of heating were established by UCBComfort software,and the models were verified based on the experimental data.The human thermal sensation was simulated by using the reasonable models after verification.The variation trend of thermal sensation with indoor ambient temperature,temperature of radiant heating terminals,radiant heating terminals' width and distance between the terminals and the human body were studied.And,in turn,the results obtained indicate that the workstation radiant heating terminal test can significantly help to improve the thermal sensation and the thermal comfort of the subjects in the needed environment.More exactly speaking,its comfort effects should be provided in a more significant way with the room-in temperature of 14 and 16 ? rather than 18 ?.For example,under the condition of the workstation radiant heating terminal(60 ?),the average thermal sensation of the subjects can be found at the temperature of 16 ? at the neutral level,which is supposed to meet 80% of the acceptable demands of the ASHRAE Standard 55.What is more,the thermal acceptability of the subjects can be greatly improved when the workstation radiant heating terminal keeps running,and,simultaneously,the thermal expectation of the subjects for warmer environments can be likely to get reduced.Besides,the thermal temperature of the workstation radiant heating terminal,which is merely expected to keep their own thermal comfort,can be raised due to the cooler ambient environment.The simulation results show that there is a change node in the thermal sensation of the human body with the change of the terminals' width and the distance between the terminals and the human body,which provides a reference for the optimization of the ways of subsequent combination and the optimization of experimental parameters.Moreover,the use of workstation radiant heating terminal can extend the set temperature range of the air conditioner in the background area,reduce the time of central heating in winter,and have the potential to save energy consumption in the residential and office buildings.