– Why do small temperature changes feel so drastic indoors compared to outdoors?


– Why do small temperature changes feel so drastic indoors compared to outdoors?

In: Physics

I don’t have a scientific answer for ya. I’m a residential HVAC guy, people will call and say they felt warm and sure enough the thermostat is a couple degrees higher than they have it set at (in summer). I think it’s the expectation based on what they’re used to. Can’t control the outside, so hot is hot. Inside people become accustom to 72, for example, and can tell when it’s higher.

People also notice hogher humidity in their home when the ac isn’t working, I’d imagine more than the actual temperature.

When your home thermostat calls for cooling at, say 72 degrees F, your air conditioning unit is producing air that is 35 to 45 degrees F. You may feel that cold air circulating as it mixes with the air in the room to keep the room at your desired temperature. This is why some people run their system fan constantly, to keep the air moving and mixing.

Similarly, when heating a room to 72 degrees F, your forced air furnace is producing air at anywhere from 110 degrees F to 170 degrees F and sending it into your room.

Outdoors, the air heats and cools more or less uniformly in a given area.

We wear less clothing indoors so we’re more sensitive to temperature changes. Also, we expect that indoors will stay a consistent temperature, so when that changes, the change feels more drastic.

There’s too many other factors outside to notice. Like humidity, wind, and the amount of clothes we wear.

(In general) people wear less and/or lighter clothing at home as well. You’re gonna be a lot more sensitive to temperature changes in a T-shirt, shorts and barefoot at home than in for example a jacket, trousers and shoes outside, even if the temperature differences are the same.

Does it?

It’s relatively rare that you can just lie down in the grass in T-shirt and shorts and be neither hot nor cold.

When you are sitting around at your perfect comfort temperature you are in kind of an equilibrium. You are neither freezing, nor are you sweating. This is only possible in a narrow temperature range.

We are used to changing our clothes for outside conditions. Sweating, wearing a jacket, opening and closing it etc.

Also outside you are often physically active, even if it’s just standing around and stomping your feet. Sweat can do a more effective job because there is almost always a light breeze.

I think when we are physically active we tend to stay on the hot and sweaty side of things. Stop on a bicycle ride, sit down on a hike or even worse: stop when you are on a run and you’ll quickly get cold (because you lack exercise to keep you warm) or hot (because you lack the breeze from moving to keep you cool, especially true with bicycling).

When you lower the AC in your house say 3F, you are lowering the air temperature AND the dew point (humidity) in the house. When the outside air temperature drops 3F, the dew point does not change so the relative humidity rises.

There are plenty of other factors mentioned elsewhere in the thread.

I don’t think any of the answers here are really particularly good. This effect is noticeable even in the tropics or in places where houses don’t traditionally have central AC like in most of Western Europe.

My personal opinion is that it’s mostly to do with sunlight. When you’re exposed to the sun it warms you up more than the air cools you down. So even if the air temperature varies, you won’t notice it much. But indoors, all you have is the ambient air. This is also why it suddenly feels a lot colder after sunset, even if the temperature didn’t really change much.