How does Air Conditioner emits cold/hot air?
In: 0
[deleted]
Air conditioners and refrigerators pump refrigerant through a closed loop. When the refrigerant goes through the pump, it gets compressed into a liquid; the liquid passes through a series of coils outside your house where a fan draws air across it cooling down the refrigerant. The liquid goes through a small nozzle and then into a special coil called an evaporator which looks like a radiator. The nozzle causes the refrigerant to expand. As it passes through the evaporator coil, it picks up heat from the air that passes over it from a fan cooling down the air. The heat it picks up and the rapid expansion causes the refrigerant to turn into a gas. The gas goes through the pump again and the cycle repeats.
If turned to cold; ac gets cold inside and blows cold air, If turned to hot; ac gets hot inside and blows hot air
Ever spray a can of compressed air? Notice how the can becomes cold. This is because loss of pressure = cooling in the physics of gas.
Now imagine you have a can of compressed air that doesn’t run out. You spray it into a radiator that has a fan blowing air through it. This cools the air being blown by the fan. Now imagine you have a tube that the used air can travel outside and get compressed to be used again. This makes the air hot. So now imagine another radiator outside with a fan blowing air through it but now it’s heating the air. Then the compressed air goes back inside to be used again.
ACs don’t actually compress air though, they use a variety of coolents that can be compressed to a liquid and then expand to a gas. To heat the indoors there’s a reversing valve that as you might imagine, reverses which unit is getting hot or cold coolent
You can try this at home.
Get some water bottles and freeze them.
Get some water in a bowl that is tepid
Put the frozen bottles int the bowl.
The cold from the frozen bottles is in contact with the other stuff and cools it down.
Your ac does the same thing. It takes a gas in a bunch of metal coils that is cold. It wraps those around something that brings in air from outside that it hot and gives it enough space and time to pick up some of the heat from the hot air and cool it down. Then a fan spits it out into the room.
It works the same with hot water coils if you don’t have a tank.
If you want to know the way the coils stay cold, it is because of the nature of the gas in the metal coils, that when you compress it it gets cold.
When you use a spray can a lot, it gets cold.
You *can* use a spray can for cooling, but spray cans are usually intended for other purposes (such as painting).
An air conditioner is basically a spray can that sprays into a metal tube. The tube gets cold, and there’s a fan that blows air over the cold tube. That’s what makes the air cold.
The biggest problem with spray cans is they run out. Except in an air conditioner, the spray can is self-refilling: The metal tube leads to a pump, and the pump keeps the spray can full and pressurized.
Another issue is the physics works in reverse, too: A gas that has its pressure released and expands gets cold, but a gas that’s pressurized by a pump and squeezed back into a spray can gets hot, in theory equal and opposite (but in practice the pumps we actually build in the real world aren’t 100% efficient and create extra heat from friction and electrical resistance).
So you handle this by having the hot, newly pressurized gas go through some outdoor tubing, and another fan to blow outside air across it.
In other words, the pump and the spray nozzle divide the loop of metal tube into two sections: A cold low-pressure section after the nozzle, and a hot high-pressure section after the pump. Blowing air over the cold section moves heat from the room to the tube, blowing air over the hot section moves heat from the tube to the outdoors. An air conditioner doesn’t destroy heat, it just moves heat from indoors to outdoors.
Latest Answers