A field study of thermal comfort in outdoor and semi-outdoor environments in subtropical Sydney Australia

In the absence of empirical outdoor thermal comfort studies it has been widely assumed that indoor thermal comfort theory generalises to outdoor settings without modification. Many indoor models were developed to describe thermal discomfort, not stress, therefore their relevance to conditions that vary greatly from neutrality, as many outdoor climatic conditions do, has not been critically validated in the field to date. The thermal comfort of 1018 subjects in outdoor and semi-outdoor locations in subtropical Sydney was investigated by a questionnaire and a comprehensive package of micro-meteorological instruments. The thermal neutrality in terms of the thermal comfort index OUT_SET* of 26.2°C was significantly higher than the indoor SET* counterpart of 24°C (ASHRAE Trans. 92 (1986) 709).