Effect of thickness of air layer under clothing on heat transmission of wearer

The air gap between human skin and clothing inner surface is one of the most important paths to transfer heat from human body to environment.By reconstructing the hot plate in a climate chamber,the fabric apparent temperature with different air gap thickness is tested and the relationship between air gap thickness and fabric apparent temperature is studied.A mathematical model is established to simulate the sensible heat originated from human skin delivered to environment through the air gap layer and the fabric.The effect of air gap thickness on heat transfer from clothed human body is analyzed.Both experimental and simulated results show that the clothing apparent temperature decreases with the air gap thickness,but the temperature begins to rise when the air gap thickness reaches 16 mm because the onset of natural convection increases the heat transfer from skin to fabric.The combination of environmental conditions and air gap thickness affects the heat transfer through clothing system.