Overall and local intrinsic clothing insulation using thermal manikin: Impact of methods employed and postures

Development of multi-node thermoregulation models with local clothing insulation as an indispensable input parameter enables distinguishing the effects of spatial and temporal changes in the thermal environment around the human body. However, the current research on local clothing insulation lags compared with multi-node thermoregulation models, affecting model prediction accuracy. The effects of the determination methods and posture on the overall and local intrinsic clothing insulation remain unknown. Therefore, in this study, the overall and local intrinsic clothing insulation values for seven typical clothing ensembles in standing and sitting postures were determined using four different methods that included thermal manikin (TM) experiments and thermal comfort standards. The results showed that (1) the overall intrinsic clothing insulation Icl differed slightly across the methods, whereas the local clothing insulation Icl,i differed substantially across the methods; (2) the overall intrinsic clothing insulation Icl for the sitting posture was 15% lower than that of the standing posture, whereas the difference in the local intrinsic clothing insulation Icl,i for the standing and sitting postures was only statistically significant at the pelvis and thigh; and (3) the local intrinsic clothing insulation Icl,i differed significantly over different body segments, and the largest Icl,i was 2.7 and 3.2 times the smallest Icl,i for the standing and sitting postures, respectively. Therefore, methods employed along with the posture affected the results of both overall and local intrinsic clothing insulation. The findings are effective in modeling sensible heat loss through clothing and contribute to improving the prediction accuracy of multi-node thermoregulation models.