Typical winter clothing characteristics and thermal insulation of ensembles for older people in China

Clothing plays an essential role in maintaining heat balance and thermal comfort for older people but varies with climate conditions and costume culture. The recommended clothing insulation in ISO 7730 and ASHRAE Standard 55 lack information on typical clothing ensemble and local insulation values for older people. To investigate the winter clothing characteristics of older people living in Shanghai, a field survey involving 342 healthy subjects from 12 aged-care homes and a lab study conducted with a 22-segment thermal manikin were performed. Subjects' typical clothing ensembles were summarized based on the survey. The local clothing insulation of 34 typical garments and 35 clothing ensembles were measured in the lab experiment. Results show that most older people in winter worn 7 pieces of clothes (excluding underpants, socks and shoes). The frequencies of typical upper and lower garments/ensembles were reported. Through manikin tests, the whole and local insulation of those typical garments and ensembles were presented. By comparison, the insulation values of garments in ISO 7730 were found to be inconsistent with tested garments' results for older people. Further, linear regression models were built to link relationships of the insulation of multiple garments and ensembles. Through running an older people-based thermoregulation model, it was found an incorrect estimation of typical winter clothing insulation for older people could lead around 1.3 degrees C deviation on predicted mean skin temperature or around 26% deviation on heat loss.