Further analysis would be useful to refine the extension of the PMV model, and additional studies in non-air-conditioned buildings in warm climates in different parts of the world would be useful to further clarify expectation and acceptability among occupants. It would also be useful to study the impact of warm office environments on work pace and metabolic rate.
Conclusions
The PMV model has been validated in the field in buildings with HVAC systems, situated in cold, temperate and warm climates and studied during both summer and winter. In non-air-conditioned buildings in warm climates, occupants may perceive the warmth as being less severe than the PMV predicts, due to low expectations.
An extension of the PMV model that includes an expectancy factor is proposed for use in non-air-conditioned buildings in warm climates.
The extended PMV model agrees well with field studies in non-air-conditioned buildings in warm climates of three continents.
Thermal comfort and air quality in a building should be considered simultaneously. A high perceived air quality requires moderate air temperature and humidity.
Acknowledgement
Financial support for this study from the Danish Technical research Council is gratefully acknowledged.
References
Andersson, L.O., Frisk, P., Löfstedt, B., Wyon, D.P., (1975), Human responses to dry, humidified and intermittently humidified air in large office buildings. Swedish Building Research Document Series, D11/75.

ASHRAE 55-1992: Thermal environmental conditions for human occupancy. American Society of Heating, Refrigerating and Air-conditioning Engineers, Inc.

Baker, N. and Standeven, M. (1995), A Behavioural Approach to Thermal Comfort Assessment in Naturally Ventilated Buildings. Proceedings from CIBSE National Conference, pp 76-84.

Brager G.S., de Dear R.J. (1998), Thermal adaptation in the built environment: a literature review. Energy and Buildings, 27, pp 83-96.

Cena, K.M. (1998), Field study of occupant comfort and office thermal environments in a hot-arid climate. (Eds. Cena, K. and de Dear, R.). Final report, ASHRAE 921-RP, ASHRAE Inc., Atlanta.

de Dear, R., Fountain, M., Popovic, S., Watkins, S., Brager, G., Arens, E., Benton, C., (1993a), A field study of occupant comfort and office thermal environments in a hot humid climate. Final report, ASHRAE 702 RP, ASHRAE Inc., Atlanta.

de Dear, R., Ring, J.W., Fanger, P.O. (1993b), Thermal sensations resulting from sudden ambient temperature changes. Indoor Air, 3, pp 181-192.

de Dear, R. J., Leow, K. G. and Foo, S.C. (1991), Thermal comfort in the humid tropics: Field experiments in air-conditioned and naturally ventilated buildings in Singapore. International Journal of Biometeorology, vol. 34, pp 259-265.

de Dear, R.J. (1998), A global database of thermal comfort field experiments. ASHRAE Transactions, 104(1b), pp 1141-1152.

de Dear, R.J. and Auliciems, A. (1985), Validation of the Predicted Mean Vote model of thermal comfort in six Australian field studies. ASHRAE Transactions, 91(2), pp 452- 468.

de Dear, R.J., Brager G.S. (1998), Developing an adaptive model of thermal comfort and preference. ASHRAE Transactions, 104(1a), pp 145-167.

de Dear, R.J., Leow, K.G., and Ameen, A. (1991), Thermal comfort in the humid tropics - Part I: Climate chamber experiments on temperature preferences in Singapore. ASHRAE Transactions 97(1), pp 874-879.

Donini, G., Molina, J., Martello, C., Ho Ching Lai, D., Ho Lai, K., Yu Chang, C., La Flamme, M., Nguyen, V.H., Haghihat, F. (1996), Field study of occupant comfort and office thermal environments in a cold climate. Final report, ASHRAE 821 RP, ASHRAE Inc., Atlanta.
Fang, L., Clausen, G., Fanger, P.O. (1999), Impact of temperature and humidity on chemical and sensory emissions from building materials. Indoor Air, 9, pp 193-201.

Fanger, P.O. (1970), Thermal comfort. Danish Technical Press, Copenhagen, Denmark. 建筑热舒适性英文文献和中文翻译(4):http://www.youerw.com/fanyi/lunwen_13883.html