Changing thermal comfort expectations: studies in Darwin, Australia

Abstract

This paper presents an examination of the thermal expectations of occupants in naturally ventilated dwellings from two studies in Darwin, Australia, conducted some 25 years apart (1988/89 and 2013/14). The 25 years between the two studies have witnessed dramatic changes in Darwin, that include a doubling of the population, considerable differences in dwelling styles offered in the market, technological developments making the installation of air-conditioning more available, relative changes in incomes, and energy prices making air-conditioning more affordable. The 1988/89 study employed Comfort Vote Logger devices to record a total of 3800 comfort votes in 16 un-air-conditioned houses during the build-up and wet seasons. The 2013/14 study involved 20 mainly free-running houses in which thermal conditions were recorded on purpose built logging instruments while the occupants recorded 2535 comfort votes over a ten-month period. Analysis presented in the paper gives a detailed comparison of the results from the two studies covering four criteria central to the adaptive comfort concept - external versus indoor temperatures, thermal acceptability, thermal sensitivity and thermal neutrality. The paper concludes with a discussion of the findings and implications of these findings for the adaptive approach to thermal comfort.