Climate, clothing and adaptation in the built environment

Specification of acceptable indoor temperatures depends, in part, on assumptions about what people will be wearing. These assumptions have implications for optimising both thermal comfort and energy conservation. Recent proposed revisions to ASHRAE Standard 55 include an adaptive comfort standard that allows a wider range of acceptable indoor temperatures, presented as a function of outdoor weather conditions. Clothing behaviour is one of the causal linkages between indoor thermal comfort and outdoor weather. This paper quantifies this relationship using a cross-sectional study of clothing insulation patterns observed in Sydney, Australia. Fifty two percent of the day-to-day variance in mean daily clo values was accounted for by daily outdoor temperature, and no statistical association between clo values and prevailing indoor temperatures. This paper concludes with an equation for a weighted running mean weekly temperature which can be used in an adaptive algorithm for defining variable indoor comfort temperatures in air conditioned buildings.