Heat transfer through protective clothing under symmetric and asymmetric long wave thermal radiation

This report considers results of an EU funded research on thermal properties of protective clothing and their use in the assessment of the thermal strain at work. In order to study the effects of the asymmetry of long wave thermal radiation on the heat transfer through protective clothing, the heat loss under all-side and unilaterally applied radiation with the same incident radiant power of 279 W/m2 was measured with a thermal manikin and compared to a reference condition where mean radiant temperature was equal to air temperature. With exposure to radiation a lowered heat loss, i.e. heat gain for the whole covered body area was observed, which did not depend on radiant asymmetry for the dry as well as for the combined dry and evaporative heat loss, and which was attenuated when wearing a more insulating underwear. However, under one-sided radiation a more inhomogeneous spatial distribution occurred with higher heat gains and higher surface temperatures at the irradiated body parts.