Study On The Change Of Clothing Thermal And Evaporative Resistance Under Different Activity Levels And Its Influence On Thermal Comfort

People spend most of their time indoors,so room thermal comfort has become one of the focuses of scholars.The results show that the main factors affecting thermal comfort include temperature,relative humidity,wind speed,average radiant temperature,metabolic rate and clothing thermal resistance.When the activity level is constant,the clothing thermal resistance is the only individual factor that can regulate the thermal sensation without affecting others.Clothing for the human body,in addition to beautiful shielding function,its main role is thermal insulation.The thermal resistance of clothing affects the heat exchange between the human body and the surrounding environment,thereby affecting the thermal sensation of the human body.Fanger proposed by Professor PMV is a widely used thermal comfort evaluation index.In the model he established,when the body dress is certain,the clothing resistance is fixed.Garment thermal resistance is measured under standard operating conditions,which is different from the actual state of clothing,and the human body environment is also different from the standard state.In addition,the metabolic rate in the model according to the level of activity set value,but at different levels of activity,the actual metabolic rate is changing,respiratory function has changed,the body to the environment heat also changes,affecting the body's thermal comfort,While affecting the thermal resistance of clothing resistance.Based on this,this paper studies the changes of resistance and thermal resistance of clothing under different activities and environmental conditions,and discusses its influence on the thermal comfort of human body.So that subjects in the constant temperature and humidity of the climate chamber wearing uniform clothing,measured the body's metabolic rate,skin temperature and other physiological indicators,the use of statistical analysis software Origin and SPSS data were processed to analyze the body and the surrounding environment,heat dissipation characteristics,And calculate the actual dress when the thermal resistance of clothing resistance,obtained the following conclusions: When the environmental parameters remain unchanged,the higher the level of human activity,the higher the body's metabolic rate,the greater the body heat,clothing resistance,On the other hand,when the level of human activity remains unchanged,the ambient temperature increases,clothing thermal resistance increases,clothing wet resistance decreases,the relative humidity increases,clothing thermal resistance decreases,clothing moisture resistance increases,and with the ambient temperature of the increase in the level of activity on the thermal resistance of clothing resistance to become smaller.The relationship between the thermal resistance and the environmental parameters of the garment under different activities was obtained by linear regression of the thermal resistance of the garment under different working conditions.According to the relevant physiological parameters obtained in the experiment heat loss and thermal resistance of clothing is calculated,this paper calculated and measured under standard conditions of PMV under PMV,and the difference of the two effects brought by the analysis.Finally,the influence of clothing thermal resistance on PMV under different activity levels is analyzed,and the influence of clothing thermal resistance change on human thermal comfort is obtained.