My wife Rachel hates air conditioning. The title is her quote, which was more profane. She truly despises it. Especially at work, where she keeps an extra sweater 24/7/365 and purposely goes outside during summer lunch breaks to warm up. In her home office, she wears a mummy bag, sometimes even during summer. Much of her life is spent shivering. This is her over the winter at a very cold AirBnB:
While Rachel is a bit extreme (she also has Raynaud’s Syndrome which leads to extra cold fingers and toes), in my practice I find men and women often resort to “thermostat wars” trying to be comfortable. Classic passive aggressive behavior. It’s a very common thing.
Basically, women’s hands and feet are cold, which most guys can attest to when their lady shocks the heck out of them by touching them with said cold body parts!
Cold hands and feet are a major comfort problem. This leads women to prefer air conditioning set points of 75, while men prefer 71. Air conditioning setpoints below 75 degrees are literally sexist.
Lower Humidity Is Key
So how do we make the two sides more comfortable? If you live somewhere that has humid summers, the solution is surprisingly simple: control humidity better. If humidity is too high, our sweat doesn’t evaporate quickly, and we get hot and sweaty. Perspiration is the main way humans cool ourselves.
Human comfort is actually all about controlled cooling. Cool too fast, and we get cold. Too slowly, and we overheat. Keeping humidity levels low enough for sweat to evaporate and keep us cool is critical.
There’s a reason the stereotype is for men to be the sweatier of the sexes. Men run higher metabolisms, about 30% faster than women, which means we generate more heat, then need to get rid of it. Gross clothing and sweat hugs ensue.
Most air conditioning systems do a lousy job keeping humidity low. If they’re too big, they don’t dehumidify well because they don’t run long enough to pull moisture out of the air. If the building is leaky and it’s a muggy day outside, moist air just leaks into the building, making the struggle to dehumidify even more futile.
If humidity levels are too high and us guys are overheating, the usual solution is to turn the thermostat down further. 68-72 is the usual band I see air conditioners set to in homes before I fix them. It’s cold enough that even if us guys are a bit clammy, at least we’re cool.
The trouble is, women are now flat out cold. They aren’t making as much heat, so they cool off faster and we get a Game of Thrones parody.
If humidity is lower, us guys can have our sweat do its job and evaporate, keeping us cool. We don’t have to crank down the thermostat to meat locker settings. Women, who need less cooling, don’t sweat as much, so they are also comfortable.
I’ve found again and again that if humidity is in the 40-50% range at 76-78 degrees, thermostat wars pretty much end. At worst a sweater is more than adequate for keeping ladies comfy instead of clammy.
Four Real World Examples
It’s natural for you not to believe me that warmer is better, so let me give you four separate examples. Note that temps are in the 76-78 range and relative humidity is between 37-45% in all of them.
Warm and Dry at the Babysitter’s
This is at my babysitter’s house. At 77 it feels cool. They don’t have central air, they have a large window unit in the basement, and they move the air around with the furnace fan. The house never gets below 75 on hot days, but humidity stays low. I find the house pretty comfy up to 84 degrees! If you move around it feels warm, but if you sit still it’s not bad. The same temps with high humidity are miserable.
These are my clients Jonathan and Kelly Nigro. Kelly is a total freeze baby in a similar vein to my wife. She wears a coat in the house almost 24/7/365. I knew we’d had a successful project when I got an email during the winter that she had actually taken her coat off!
Jon posted the video above of Kelly wearing a coat on a day that had touched 90 degrees, as warm as it usually gets here in Cleveland. Because the humidity was low in the house, 77 actually felt cold to her when walking inside from a hot day. They usually keep the thermostat at 80. I’ve been there, it’s very comfy, and I’m a sweat hog if humidity is too high.
Mold Sensitivities Reduced, Comfortably
A screenshot of a client thermostat during an experiment to see how low we could get humidity levels in the home. This was too dry, my client noted that her sinuses were drying out! In August! That’s normally a winter problem, but it gives you an idea of just how much control Home Performance can give you. The temperature is very comfortable in the house at 77. These low humidity levels appear to be drastically reducing symptoms for a mold sensitive individual, I look forward to writing the case study on this – humidity control is one of the keys.
Comfy at a Buddy’s House
This last one is at a friend’s house. It was a very hot day in the low 90s. (It’s still 82 at 11 PM!) Note how low the humidity was, 37%! This was quite comfortable despite the fact that the house itself was warm after soaking up the sun all day. On more moderate days, it’s set at 78-80.
In all four of these examples, men and women are coexisting comfortably in air conditioning with humidity in the 40-50% range. There is no Women’s Winter. No Game of Thrones action or thermostat wars. In all four, humidity is under pretty tight control. That’s the key to both sexes being comfortable in summer. Now if I can only get my wife to hate AC a little less. Then I can actually get it in my own home and stop huddling in the basement to keep cool…
How to Accomplish Low Humidity
Getting control over humidity is not an easy task, though. First, a building needs to be reasonably airtight so that the air conditioner isn’t struggling futilely to remove moisture that pours in through leaks from outdoors. Second, the right HVAC system is needed, one that is capable of removing lots of humidity as close to 24/7 as possible. That usually means smaller, multiple speed air conditioners. Yep, another counterintuitive conclusion.
Curious to learn more about that? Download our free HVAC Guide, it will walk you through what it takes to make a house or office comfortable not only in summer, but year round.
Free HVAC Guide
Learn how really good heating and cooling systems work. And how to get one.
You can actually calculate what temperature and humidity levels are likely to be comfortable for the most people using this calculator on Robert Bean’s excellent Healthy Heating website. Robert is one of the best comfort experts in the world. Here’s the typical office scenario:
Robert is Canadian, so we’re stuck with Celsius. =) 22 C is about 72 F. Pretty typical settings. Fairly high humidity at 60% relative. Light clothing, just a shirt and pants. 35% of people are predicted to be unsatisfied, and you can bet most of those are female. A number of guys will still be a bit warm.
This is the scenario I talk about in the article. 25C is 77F. Humidity is a bit lower at 50%, which many HVAC systems are capable of. Clothing is a touch heavier, this is a woman in a business suit. The lowest dissatisfied percentage with this calculator is 5%, so this is about as good as it gets for summer.
Get the HVAC Guide
It's free! Make buying a new furnace, air conditioner, or heat pump less stressful.
Success! Look for an email from me (Nate Adams) to download the guide.