Hello! Would appreciate any basic explanation on how airconditioners work. Mine just got busted (and I’m from a very hot, tropical country!). I’m tempted to just call the maintenance guy, but I thought it would be a good opportunity to first learn about it before spending some dough. I’ll be using A/C units all my life anyway.
Been watching some YT videos but once terms like “latent heat vaporization” are mentioned, my mind just shuts off. Many thanks to all the articulate and patient folks out there!
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Evaporation of liquid to gas uses heat (temperature drops). The flip side is that when you condense gas to liquid, it gives off heat. This only really works when volume is constant and pressure change is the reason for the heating or cooling. Special gases (chemicals) are used as coolant that evaporate and condense pretty well in the range needed, and take or give a lot of heat in the process. Not any old chemical will do the job.
So, heat exchange systems like a fridge or air-con has a closed system that passes inside the area to be cooled, where pressure is low and the liquid evaporates, cooling things. The gas is then passed outside the area to be cooled, where it is compressed, heating it up. The heat is moved from INSIDE to the outside.
If you blow air over the cold zone (coiled tubes, usually), it will cool the area it is in fairly quickly. Outside, though, it is heating things up. Normally, “outside” is literally, physically, out on the wide open atmosphere, so the heat is tiny compared to the amount of air, and unless you stand right next to the fan of the AC/fridge, you don’t notice it.
A fridge in a house, or big fridges in stores or factories or whatever, can put out enough heat to affect room temperature. Usually don’t because fridges don’t need to run a lot, but if you keep opening the fridge or air is leaking in and out of it so the fridge runs a lot, you might actually heat up the room quite a bit, and notice it. Industrial and large commercial systems tend to push that air to the outside to avoid this possible problem.
Now, if the coolant (the liquid/gas used to move heat by evaporation/condensation) runs out (maybe a small leak in a coil or something, blown gasket on a compressor that pressurizes the gas), then the system won’t work.
Most failures to coolant systems are either due to loss of coolant fluid, or failure of the compressor.
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