Prediction of clothing thermal insulation and moisture vapour resistance.

摘要

Clothing thermal insulation and moisture vapor resistance are two most important clothing properties with respect to thermal comfort. With a newly constructed climate chamber and an improved sweating manikin-Walter with patent pending innovations in terms of the simulation of "walking" motion and real-time water loss measurement, the thermal insulation and moisture vapour resistance of the nude and clothed manikin had been measured simultaneously for the first time under various conditions. It was found that the effect of walking speed is very similar to that of wind velocity on the clothing thermal insulation and moisture vapour resistance. The reduction ratios of total thermal insulation and moisture vapour resistance of clothing and the dry and latent heat transfer coefficients induced by air ventilation and wind penetration were almost linearly related to the effective wind velocity.; The present study showed that there is no significant difference between the surface thermal insulation measured on the non-sweating manikin and those measured on the sweating manikin. The surface moisture vapour resistances measured under isothermal conditions tend to be greater than those measured under non-isothermal conditions. Lewis relation holds under non-isothermal conditions.; Based on improved understanding of the effects of wind and walking motion on the heat and moisture transfer through clothing, the present study proposed two new models, the direct regression model and the quasi-physical model, for the prediction of the dynamic clothing thermal insulation and moisture vapour resistance under windy conditions and walking motion from the static values when a clothed person is standing in "still" air. The models can take into account the effects of clothing characteristics through the model parameters. The direct regression model is very simple and effective, but the quasi-physical model has the advantage of incorporating the fundamental mechanisms of heat and moisture transfer. Validation and comparison of the two new models with the published existing models, by applying the models to fit experimental data from both the present investigation and published sources, showed that the prediction accuracy of the direct regression model is very high in most instances, but the quasi-physical model provided the best prediction accuracy.