Gita Subramony for Zondits, August 17, 2015. Image credit: ashirova0
It turns out I’m not the only person who is unbearably cold in the summer…when I’m at work. A recent study demonstrated why many women (myself included) persistently feel cold in the summer when they are at work. HVAC design methods seemingly do not take into account metabolic differences between women and men, nor do they consider differences between typical men’s and women’s office attire. Men on average have slightly higher metabolic resting rates than women and are often found in suits while in the office. As a result, office temperatures are usually lower than they should be. While some find the temperatures comfortable, others find that having a “work sweater” or “office Snuggie” is necessary. Designing HVAC systems to take into account these differences could reduce building load, reduce energy usage, and potentially contribute to the fight against climate change. HVAC design, however, is not the only factor. Often, office building thermostats are set far lower than recommended, so it’s not just a design issue but also a behavioral one.
Building standards aren’t to blame for chilly offices
Science News, August 11, 2015
Buildings are generally designed to meet standard guidelines for heating and cooling. The building’s ability to keep us cool is based on a series of complex equations that take into account humidity, air temperature, airflow, radiant temperature and the metabolism of the humans theoretically present.
But these complex equations are based on a single metabolic average, says Boris Kingma, a biophysicist at Maastricht University Medical Center in the Netherlands — the average metabolic rate of a 40-year-old man who weighs 70 kilograms, or about 154 pounds. If this man seems a bit on the thin side, it’s because he’s an average, a single number representing the metabolic rates of many people. This hypothetical guy has a resting metabolic rate of 58 watts per square meter. This number goes into the calculations when considering the heating and cooling demands of a building when people are in it.
“If you design a building and you say it’s for 1,000 people, you’re [currently] calculating a thermal load based on 1,000 men,” Kingma says. “You’re computing with an internal load higher than it should be.”