The conventional methods of estimating the thermal comfort properties of clothing materials (thermal resistance and water vapour permeability) are not suitable for cold weather clothing materials, where a substantial condensation of water vapour takes place in the textiles.A new apparatus, the sweating cylinder, was constructed, which measures simultaneously the heat and moisture transfer in textile systems.A test series was performed, in which 24 material combinations for winter work wear were tested in 3 environment temperatures (0, -20, and -40 °C) and at 2 sweating levels (72 and 145 ml/m²h).The thermal resistance and moisture evaporation values were determined and compared with values from standard measurements.The results show that the thermal resistance of the clothing decreases with an increasing sweating level.The water vapour is only partly transmitted through the textile layers and partly condensates within them.Particularly at -40 °C most of the water remains in the textiles.The correlation of the results from the sweating cylinder with standard thermal resistance measurements is fair at low but poor at high sweating levels.The correlation between standard water vapour transmission tests and evaporation on the cylinder is poor.The test series proved that the sweating cylinder is a valuable instrument for measuring the heat and moisture transmission through textile materials in different environments.After some technical refinements it will be introduced as a standard test method to other research laboratories.
|Award date||7 Oct 1985|
|Place of Publication||Espoo|
|Publication status||Published - 1985|
|MoE publication type||G4 Doctoral dissertation (monograph)|
- heat transmissions