Model for Predicting the Effect of an Air Gap on the Heat Transfer of a Clothed Human Body

Considering a clothing system consists of the human body, an air gap layer under the clothing as well as a fabric layer and boundary layer adjacent to the fabric, heat transfer from the skin to the environment is influenced by human body thermoregulation, the air gap, the fabric and environmental conditions. Based on Stolwijk’s 25-node thermoregulatory model, a new mathematical model was developed to include the sensible and latent heat transfer through the air gap, fabric layer and boundary layer adjacent to the fabric. To quantify the effect of the air gap on human body heat transfer, a 3D human body scanner was utilised to measure the air gap thickness of five experimental garments of increasing chest circumference. The model can be used to predict the apparent clothing temperature and heat loss from the human body when people are dressed in differently sized clothing.