How can the aircon be at the same temperature for both heating/cooling modes and feel different?
In: 79
One thing that a lot of the replies have missed also is the fact that how the AC determines when to turn off is very imprecise.
Example: if you set the temp to 70 F and the room is currently above that, say 72 F, the AC will blow Very Cold Air until after the temp is Below 70 F. So it basically blows cold until it is pretty close to 69 F. But if the temp is set to 70 F and it’s currently lower than that, say it’s 68 F, the Heat will turn on and blow Very Hot Air until it’s Above 70 F so that it doesn’t actually turn off until it’s pretty much 71 F.
Also, our bodies are very sensitive to temp, as that is one of the things that can kill us is low or high temps. So just one or two degrees is very noticeable. This all combines with what others have been describing about how your body detects changes in temp rather than detecting a specific temp. Like your body has no clue whether it’s currently 70 F or 65 F. It only knows that it’s either colder or warmer than it was. And the faster the temp changes, the more alarmed your body gets, and it will feel like a greater change in temp if it happens very quickly.
One thing that a lot of the replies have missed also is the fact that how the AC determines when to turn off is very imprecise.
Example: if you set the temp to 70 F and the room is currently above that, say 72 F, the AC will blow Very Cold Air until after the temp is Below 70 F. So it basically blows cold until it is pretty close to 69 F. But if the temp is set to 70 F and it’s currently lower than that, say it’s 68 F, the Heat will turn on and blow Very Hot Air until it’s Above 70 F so that it doesn’t actually turn off until it’s pretty much 71 F.
Also, our bodies are very sensitive to temp, as that is one of the things that can kill us is low or high temps. So just one or two degrees is very noticeable. This all combines with what others have been describing about how your body detects changes in temp rather than detecting a specific temp. Like your body has no clue whether it’s currently 70 F or 65 F. It only knows that it’s either colder or warmer than it was. And the faster the temp changes, the more alarmed your body gets, and it will feel like a greater change in temp if it happens very quickly.
Because the air is unlikely to be fully mixed, and you’re feeling the stratification
In a room with the ceiling fan running on reverse (pulling air) it’ll feel more similar
Because the air is unlikely to be fully mixed, and you’re feeling the stratification
In a room with the ceiling fan running on reverse (pulling air) it’ll feel more similar
There are a lot of good answers here. Another thing to remember is that when you heat air, the mass of water stays the same, so the relative humidity drops. Cool air is significantly drier (in terms of water mass) than warm air.
As an example, if you maintain 74 degrees, air conditioning should drop the dewpoint to approximately 52 degrees, which is a relative humidity of about 46%. But if it’s 35 degrees outside, your dewpoint can’t be higher than 35, and is probably much lower. This means the relative humidity is only 24% or lower, a very noticeable difference that will certainly impact comfort.
There are a lot of good answers here. Another thing to remember is that when you heat air, the mass of water stays the same, so the relative humidity drops. Cool air is significantly drier (in terms of water mass) than warm air.
As an example, if you maintain 74 degrees, air conditioning should drop the dewpoint to approximately 52 degrees, which is a relative humidity of about 46%. But if it’s 35 degrees outside, your dewpoint can’t be higher than 35, and is probably much lower. This means the relative humidity is only 24% or lower, a very noticeable difference that will certainly impact comfort.
Because the A/C doesn’t heat or cool to exact temperatures. Let’s say you have your A/C set to 72f cool. It will actually cool your house to 70f and wait for it to warm up to 74f before it comes on again. In order to get your house to 70f it will actually blow air cooler than 70f into your house. It will be blowing air around 52f until the average temperature at your thermostat reacher 70f.
For heating the air temp at the vent depends on what kind of system you have. A heat pump will be around 90f-100f and a furnace may be as warm as 120f. If your A/C is set to heat it will bring the average temperature up to about 74f and wait for it to drop to 70f before it comes back on.
The actual temperature it turns on/ff at will depend on the manufacturer of your thermostat and how much control you have over the settings. My thermostat in my house is programmable so I can adjust those settings and even turn just the fan on to get the air circulating.
Because the A/C doesn’t heat or cool to exact temperatures. Let’s say you have your A/C set to 72f cool. It will actually cool your house to 70f and wait for it to warm up to 74f before it comes on again. In order to get your house to 70f it will actually blow air cooler than 70f into your house. It will be blowing air around 52f until the average temperature at your thermostat reacher 70f.
For heating the air temp at the vent depends on what kind of system you have. A heat pump will be around 90f-100f and a furnace may be as warm as 120f. If your A/C is set to heat it will bring the average temperature up to about 74f and wait for it to drop to 70f before it comes back on.
The actual temperature it turns on/ff at will depend on the manufacturer of your thermostat and how much control you have over the settings. My thermostat in my house is programmable so I can adjust those settings and even turn just the fan on to get the air circulating.
Air conditioners evaporate the air which makes the air dry relative to the humidity of the air that’s making the humidity, this evaporated air hits the sweat on your body which causes the sweat to evaporate, which is fundamental to the cooling system of a body. Heat is warm air added to the space that does not go through an evaporation process, and you aren’t sweating when your cold, so that cooling system of the body is not being triggered.
Air conditioners evaporate the air which makes the air dry relative to the humidity of the air that’s making the humidity, this evaporated air hits the sweat on your body which causes the sweat to evaporate, which is fundamental to the cooling system of a body. Heat is warm air added to the space that does not go through an evaporation process, and you aren’t sweating when your cold, so that cooling system of the body is not being triggered.
Latest Answers