Thermal comfort is the condition of mind that expresses satisfaction with the thermal environment and is assessed by subjective evaluation (ANSI/ASHRAE Standard 55). Maintaining this standard of thermal comfort for occupants of buildings or other enclosures is one of the main goals of HVAC (Heating, Ventilation, and Air Conditioning) design engineers.
Thermal neutrality is maintained when the heat generated by human body is allowed to dissipate, hence maintaining thermal equilibrium with the surroundings. The main factors that affect thermal comfort are those that determine heat gain and loss, i.e. metabolic rate, air speed and temperature and humidity, clothing insulation and mean radiant temperature. Psychological parameters such as individual expectations also affect thermal comfort.
Battle Of The Thermostat
One conflict that will probably never end is the Battle of the thermostat in a space shared by men and women. Whether it’s family or roommates, or co-workers or classmates, finding that sweet spot temperature that will suit everyone can be hard.
Typically men are turning thermostat down and women are two steps behind them turning it right back up again. There’s actually a lot of biology and psychology explaining why women often find themselves feeling much chillier than the men in the same room. Here is the real reasons:
Cold Hands, Warm Heart:
Women’s cold hands and feet are a long-running joke between couples at bedtime however there’s science behind it. Study published in The Lancet medical journal in 1998 showed that on average women’s core temperatures are higher than men’s, while they are more likely to have cold hands than men. The study revealed that men’s hands are about 3oF warmer than women’s. The fact is women’s bodies are better at dragging heat back to their organs to save it for cold situations.
Thus, the feet and hands pay the price for keeping essential organs operating at higher temperature. That’s why when you are walking through a cold space, you see more women rubbing their hands together than men to get warm.
Fat To Muscle Ratio
How cold a person feels has a lot to do with the way our bodies are composed. Generally women have more fat and less muscle than men. It’s important to mention that higher fat percentage ratio doesn’t necessarily mean unhealthier. Yes, women have larger fat storage, but it is part of their physiology, meaning it’s not extra weight.
As muscle is better at heat production, this gives men an advantage to keep themselves warm in cool temperatures. In fact fat acts as an insulation, it traps heat at the core, so the core will tend to remain warm while the skin cools down. As soon as your skin cools down, you’ll cool down even if your core is still warm.
A fact that has been annoying women for years is men naturally have higher metabolic rates than women. According to the studies the metabolic rate of most men is about 23% higher than women’s. This not only means men burning fat easier, but also means they have warmer body. Metabolism is the breakdown of molecules to obtain energy and generate heat for our body. Since women’s bodies are burning less energy it is understandable that they can tolerate hot climate better than men.
Body size also has a lot to do with how warm a person feels. Normally men are larger than women both in height and weight. According to the studies there is a correlation between body size and body temperature. Based on the study done by Brad Fiero, faculty member at Pima Community College, since women tend to be shorter, they usually have a bigger surface area to volume ratio than men. This leads to more heat loss at a higher rate through their bigger surface area.
Office Temperature And Attire
Women who spend their days in office buildings tend to find themselves in a rough spot when it comes to dressing for the weather. Finally proved what women have known all along office temperatures are designed for the comfort of a man. A 2015 study published in Nature Climate Change revealed that “Indoor climate regulations are based on an empirical thermal comfort model that was developed in the 1960s. Standard values for one of its primary variables—metabolic rate—are based on an average male, and may overestimate female metabolic rate by up to 35% “. This might have been justifiable decades ago when most offices were mainly men but it’s much less make sense these days when the number of women equal, if not exceeded, the number of men.
The study also revealed that the outdated thermal comfort formulas used by offices everywhere takes into account another factor: Clo value or Clothing’s thermal properties. Men wear suits and it can make them hot. Pair the icy office temperature with women’s regular office dresses such as skirts and thin shirts, and you’ll understand what all the shivering is about. And why under the women’s desk a heater is stored, gloves and scarves are stashed in their drawers. In the summer time the A/C usually gets cranked up to near freezing point, blowing fundamentals of energy conservation right out the window.
In conclusion, women have the advantage in the summer, as well as with an ever-warming climate, while men have the advantage in the winter, as well as historical control temperature settings in most buildings and workplaces.
So in any new HVAC design thermal comfort of both gender must be taken into consideration. Moreover instead of using the outdated thermal comfort formulas, the modified version which take into account today office seasonal dress codes should be used. On the other hand offices should encourage a more climate-friendly mode of dressing. That may mean encouraging men to dress much cooler in the summer (short sleeves, short pants, sandals) while women dress warmer in the winter (cardigans or jackets, long pants or thicker tights). This can ease the strife and save energy too.
Considering the new normal that wearing the mask is mandatory in almost all indoor areas, new factor may need to be added into the formulas to reflect the effect of wearing mask in thermal comfort.