Warm-blooded men who luxuriate in the ice-cold temperatures of an air-con system operating at full blast in the height of summer are doing so at the expense of their pashmina-wrapped female colleagues.
Indoor climate control systems are based on the resting metabolic rate of an average 40-year-old man, who is likely to feel more comfortable at a lower temperature than women, say scientists.
A study of 16 young women performing light office work showed that they were at risk of being over-chilled by air conditioning in summer, Nature Climate Change reported.
Their metabolic rates, significantly lower than the “standard values” currently employed to set office temperatures, suggested they required less cooling in summer than men.
Current air conditioning standards are derived from research conducted in the 1960s that assessed the “thermal comfort” of 1,300 mainly sedentary students.
It took into account a value for metabolic rate, which was based on the resting metabolic rate of one 70 kilogram (11 stone) 40-year-old man.
However women’s metabolic rates are typically very different from men’s, pointed out the study authors Dr Boris Kingma and Professor Wouter van Marken Lichtenbelt, from Maastricht University Medical Centre in the Netherlands.
The standard model used to set indoor temperatures may overestimate the amount of heat generated by a woman sitting still by up to 35%, the researchers said. Metabolic rate also lowered with increasing age.
Studies found that “women tend to be cooler than men in cool conditions” and were “more sensitive than men to fluctuations in the optimum temperature.”
A study found that the neutral temperature for Japanese women was 25.2 °C, whereas it was 3.1 °C lower for European and North American men under the same conditions. Finnish research found that women were “less satisfied with room temperatures, preferred higher room temperatures, and felt both uncomfortably cold and uncomfortably hot more often than men.”
The authors wrote: “Thus, current indoor climate standards may intrinsically misrepresent thermal demand of the female and senior sub-populations.”
This in turn was likely to make office heating and cooling systems less energy efficient than they could be, they added. The authors called for a new system that takes into account gender differences, as well as age and physiological characteristics such as being lean or obese.
“Thermal comfort models need to adjust the current metabolic standard by including the actual values for females,” the authors said. “This in turn will allow for better predictions of building energy consumption, by reducing the bias on thermal comfort of sub-populations and individuals.”
The gender comfort disparity had never been factored into the design of building thermal systems even though the “improved comfort of both male and female office workers may improve productivity in some of their tasks.”
In a commentary in the journal, Dr Joost van Hoof from Fontys University of Applied Sciences in the Netherlands, wrote: “These findings could be significant for the next round of revisions of thermal comfort standards – which are on a constant cycle of revision and public review – because of the opportunities to improve the comfort of office workers and the potential for reducing energy consumption.
A large scale re-evaluation in field studies may be needed in order to sufficiently convince real-estate developers, standard committees and building services engineers to revise their practises.”
Source: Independent UK