Codes and Standards

Difference in male-female thermal comfort is due to clothing, ASHRAE says

Aug. 6, 2015
2 min read

Recent research that looks at the method used to determine thermal comfort in ANSI/ASHRAE Standard 55 published in an article, “Energy Consumption in Buildings and Female Thermal Demand,” in Nature Climate Change, misinterpreted data, according to ASHRAE

“The interpretation of the authors regarding the basis for Standard 55 is not correct,” Bjarne Olesen, Ph.D., a member of the ASHRAE Board of Directors, thermal comfort research and former chair of the Standard 55 committee, said. “The part of the standard they are referring to is the use of the PMV/PPD index. This method is taken from an ISO/EN standard 7730, which has existed since 1982. The basic research for establishing comfort criteria for the indoor environment was made with more than 1,000 subjects with an equal amount of women and men.

“In the main studies, where they did the same sedentary work and wore the same type of clothing, there were no differences between the preferred temperature for men and women. So the researchers’ finding of a lower metabolic rate for females will not influence the recommended temperatures in the existing standards. Also their study is not conclusive. They only studied 16 females at a sedentary activity.

“They should also have studied 16 men at the same activity to be able to compare. The reason why we, in some field studies, find that women prefer higher room temperature than men is attributed to the level of clothing. Women better adapt their clothing to summer conditions while men are still wearing suits and ties. So if the thermostat is set to satisfy the men, the women will complain about being too cold. In the standard, this adaption of clothing to summer is taken into account. So if the standard is followed, the women would be satisfied; but maybe not the men.”

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