While spending a holiday in the New Orleans and Mississippi region, I was baffled by the typical temperatures in air-conditioned rooms. The point of air conditioning is to make people feel comfortable, right? It is obviously very bad at achieving this. I saw shivering girls with blue lips waiting in the airport. I saw ladies wearing a jacket with them which they put on as soon as they entered an air-conditioned room. The rooms were often so cold that I felt relieved the moment I left them and went back into the heat. Cooling down less than to the optimally comfortable temperature would make some economical and ecological sense, and would make the transition between outside and inside less brutal. Cooling down more seems patently absurd.
What is going on here? Some possible explanations that come to mind:
Employees who have to wear suits and ties prefer lower temperatures than tourists in shorts and T-shirts.
Overweight people prefer lower temperatures than skinny girls, and the high obesity rates in America are well-known.
Some places (like airports) may intentionally want to prevent people from hanging around for too long without a good reason.
Still, the above points seem nowhere near sufficient to explain the phenomenon. The temperatures seem uncomfortably low even for people wearing a suit with a tie. Places like cinemas clearly want their customers to feel comfortable, and their employees don’t wear suits.
First, the temperature will be uneven throughout any given building. In order to ensure that the outskirts of a large building are adequately cooled, the interior may end up frigid. This effect is more pronounced with larger buildings. Please complain to your nearest HVAC contractor, not to us poor Texans.
Second, people who are just coming in from 115 F outdoor temperatures actually tend to want it to be nice and cold inside. Believe me.
Third, the outdoor temperature varies over the course of a day. A thermostat setting that resulting in an acceptable actual indoor temperature at noon might be causing very cold indoor temperatures at 6 PM, even though nobody touched the thermostat.
Fourth, colder air is drier, which causes sweat to evaporate faster. So there’s a sweat-evaporating benefit along with the rapid cooling benefit, which is very beneficial and widely appreciated when every single person entering a building is drenched in sweat.
The best way to learn these lessons is to simply live in Texas and observe your own behavior vis-a-vis air conditioning preferences.
Fourth, colder air is drier, which causes sweat to evaporate faster.
No, it does not work that way. Artificially cooling air without taking water out of it decreases its equilibrium vapor pressure while keeping its absolute humidity constant, thereby increasing its relative humidity and making it worse at drying things. (Conversely, artificially heating air without adding water to it makes it better at drying things.)
As Lumifer said, air conditioners extract water from the air. Then the air warms up again slightly as it percolates through the building. The net effect is enhanced drying.
Not sure what “powerful” means in this context. I have a degree in chemical engineering so I’m moderately confident that I understand compression and saturation pressure. Saturation pressure of water in air declines with temperature. Making the air colder reduces the humidity of the air, and this is true all the way down to the freezing point of water. In a large building, you will have a pump outlet temperature much lower than the thermostat setpoint. For example, the coils themselves may be operating at 25-45 F, even though the air in in the building at large may be 75 F. The consequence of this is that the percent saturation (“humidity”) of the air will be significantly lower than the outdoor humidity. The net effect will be perceptible drying.
Air-conditioning is higher status than no air-conditioning. Higher-status people are more likely to live with air-conditioning; lower-status people are more likely to live without it. Lower-status people will feel more inconvenienced by too much air-conditioning, because it is a greater shock for them. Complaining about too much air-conditioning is an evidence of lower status. People who want to seem higher-status will avoid complaining about air-conditioning (and maybe just dress warmer). If all high-status people agree that the air-conditioning is okay as it is, it will remain as it is, because higher-status people make the decisions.
I think you get more of that in Texas and the southeast. It (by my observation—very much a stereotype) correlates with driving big trucks, eating big meals, liking steak dinners and soda and big desserts, obesity, not caring about the environment, and taking strong unwavering opinions on things. And with conservatism, but not exclusively.
I distinctly remember driving in my high school band director’s car once, maybe a decade ago, and he was blasting the AC at max when it maybe needed to be on the lowest setting, tops—it seemed to reflect a mindset that “I want to get cold NOW” when it’s hot, to the point of overreaction. Maybe a mindset that—if the sun is bright and on my face, I need a lot of cold air, even if the rest of me doesn’t need it? Or maybe, ‘it feels hot in the world so I want a lot of cold air’. Certainly there was no realization that it was excessive, and he didn’t seem bothered by the unnecessary use of resources. I’ve noticed this same mindset a lot ever since, and I still don’t understand it.
The optimal AC setting in terms of comfort is subjective. I don’t see any reason to speculate beyond the simple fact that he was hot. I don’t think anyone should care about “unnecessary uses of resources”- that’s why we have markets.
I don’t think anyone should care about “unnecessary uses of resources”- that’s why we have markets.
That would apply if there were no such things as subsidies or negative externalities—if all of the costs associated with cooling a room to a given temperature were always paid by the person who decided the temperature.
No, markets only work for services whose costs are high enough to participants to care and model their behavior accordingly. In my observation, specifically, these people behave this way for reasons other than their personal comfort, and the costs aren’t high enough (or they’re not aware that they’re high enough) to influence their behavior.
The ‘reason to speculate’ is that it’s interesting to talk about it. That’s all.
Cooling down less than to the optimally comfortable temperature would make some economical and ecological sense …. Cooling down more seems patently absurd.
There is no “optimally-comfortable temperature”—different folks want different temps! The optimum choice is in fact to have two rooms/environments, one of which cools down a bit more, the other less (or not at all). If you feel cold, just spend some time in the warmer room.
Yeah, this is a thing, and I hear plenty of Americans make baffled complaints about it as well.
I don’t know the answer, but this is my guess. A while back, there was a flurry of news sites talking about air conditioning being “sexist”. The short version is that standards for climate control were all written when offices were full of men in suits. Times have changed, in terms of who’s wearing what in which buildings, but things like building codes and temperature guidelines haven’t caught up.
Dear Americans,
While spending a holiday in the New Orleans and Mississippi region, I was baffled by the typical temperatures in air-conditioned rooms. The point of air conditioning is to make people feel comfortable, right? It is obviously very bad at achieving this. I saw shivering girls with blue lips waiting in the airport. I saw ladies wearing a jacket with them which they put on as soon as they entered an air-conditioned room. The rooms were often so cold that I felt relieved the moment I left them and went back into the heat. Cooling down less than to the optimally comfortable temperature would make some economical and ecological sense, and would make the transition between outside and inside less brutal. Cooling down more seems patently absurd.
What is going on here? Some possible explanations that come to mind:
Employees who have to wear suits and ties prefer lower temperatures than tourists in shorts and T-shirts.
Overweight people prefer lower temperatures than skinny girls, and the high obesity rates in America are well-known.
Some places (like airports) may intentionally want to prevent people from hanging around for too long without a good reason.
Still, the above points seem nowhere near sufficient to explain the phenomenon. The temperatures seem uncomfortably low even for people wearing a suit with a tie. Places like cinemas clearly want their customers to feel comfortable, and their employees don’t wear suits.
Thanks for clarifying.
First, the temperature will be uneven throughout any given building. In order to ensure that the outskirts of a large building are adequately cooled, the interior may end up frigid. This effect is more pronounced with larger buildings. Please complain to your nearest HVAC contractor, not to us poor Texans.
Second, people who are just coming in from 115 F outdoor temperatures actually tend to want it to be nice and cold inside. Believe me.
Third, the outdoor temperature varies over the course of a day. A thermostat setting that resulting in an acceptable actual indoor temperature at noon might be causing very cold indoor temperatures at 6 PM, even though nobody touched the thermostat.
Fourth, colder air is drier, which causes sweat to evaporate faster. So there’s a sweat-evaporating benefit along with the rapid cooling benefit, which is very beneficial and widely appreciated when every single person entering a building is drenched in sweat.
The best way to learn these lessons is to simply live in Texas and observe your own behavior vis-a-vis air conditioning preferences.
No, it does not work that way. Artificially cooling air without taking water out of it decreases its equilibrium vapor pressure while keeping its absolute humidity constant, thereby increasing its relative humidity and making it worse at drying things. (Conversely, artificially heating air without adding water to it makes it better at drying things.)
As Lumifer said, air conditioners extract water from the air. Then the air warms up again slightly as it percolates through the building. The net effect is enhanced drying.
The more powerful the AC, the less it dehumidifies. How about you talk to an HVAC contractor.
Not sure what “powerful” means in this context. I have a degree in chemical engineering so I’m moderately confident that I understand compression and saturation pressure. Saturation pressure of water in air declines with temperature. Making the air colder reduces the humidity of the air, and this is true all the way down to the freezing point of water. In a large building, you will have a pump outlet temperature much lower than the thermostat setpoint. For example, the coils themselves may be operating at 25-45 F, even though the air in in the building at large may be 75 F. The consequence of this is that the percent saturation (“humidity”) of the air will be significantly lower than the outdoor humidity. The net effect will be perceptible drying.
Yeah, but that’s not what air conditioners do. They do take water out of the air via condensation on the coils.
Some form of signalling?
Air-conditioning is higher status than no air-conditioning. Higher-status people are more likely to live with air-conditioning; lower-status people are more likely to live without it. Lower-status people will feel more inconvenienced by too much air-conditioning, because it is a greater shock for them. Complaining about too much air-conditioning is an evidence of lower status. People who want to seem higher-status will avoid complaining about air-conditioning (and maybe just dress warmer). If all high-status people agree that the air-conditioning is okay as it is, it will remain as it is, because higher-status people make the decisions.
I think you get more of that in Texas and the southeast. It (by my observation—very much a stereotype) correlates with driving big trucks, eating big meals, liking steak dinners and soda and big desserts, obesity, not caring about the environment, and taking strong unwavering opinions on things. And with conservatism, but not exclusively.
I distinctly remember driving in my high school band director’s car once, maybe a decade ago, and he was blasting the AC at max when it maybe needed to be on the lowest setting, tops—it seemed to reflect a mindset that “I want to get cold NOW” when it’s hot, to the point of overreaction. Maybe a mindset that—if the sun is bright and on my face, I need a lot of cold air, even if the rest of me doesn’t need it? Or maybe, ‘it feels hot in the world so I want a lot of cold air’. Certainly there was no realization that it was excessive, and he didn’t seem bothered by the unnecessary use of resources. I’ve noticed this same mindset a lot ever since, and I still don’t understand it.
The optimal AC setting in terms of comfort is subjective. I don’t see any reason to speculate beyond the simple fact that he was hot. I don’t think anyone should care about “unnecessary uses of resources”- that’s why we have markets.
That would apply if there were no such things as subsidies or negative externalities—if all of the costs associated with cooling a room to a given temperature were always paid by the person who decided the temperature.
Well that’s why we have governments...
Yeah, but I don’t think they’re anywhere near reliable enough that no-one “should care about unnecessary uses of resources”...
No, markets only work for services whose costs are high enough to participants to care and model their behavior accordingly. In my observation, specifically, these people behave this way for reasons other than their personal comfort, and the costs aren’t high enough (or they’re not aware that they’re high enough) to influence their behavior.
The ‘reason to speculate’ is that it’s interesting to talk about it. That’s all.
There is no “optimally-comfortable temperature”—different folks want different temps! The optimum choice is in fact to have two rooms/environments, one of which cools down a bit more, the other less (or not at all). If you feel cold, just spend some time in the warmer room.
Yeah, this is a thing, and I hear plenty of Americans make baffled complaints about it as well.
I don’t know the answer, but this is my guess. A while back, there was a flurry of news sites talking about air conditioning being “sexist”. The short version is that standards for climate control were all written when offices were full of men in suits. Times have changed, in terms of who’s wearing what in which buildings, but things like building codes and temperature guidelines haven’t caught up.