How air conditioner works and what is the work of ac outdoor fan?

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How air conditioner works and what is the work of ac outdoor fan?

In: Engineering

4 Answers

Anonymous 0 Comments

The outside part is the compressor and condenser. Its job is to remove the heat from the inside of the house. Inside (located in the sheet metal box (plenum) above your furnace, assuming central AC is a similar set up. But instead of a compressor is a metering valve (think of it as an ‘expander’, the opposite of a compressor). When the high pressure liquid passes through the valve, it enters a low pressure area. The low pressure causes the liquid to boil and turn to gas, which absorbs heat from the surrounding area (which is why it’s cold). That low pressure gas goes to the compressor, which turns it into a high pressure gas which forces it back into a liquid which requires it to dump all that excess heat.

Confusing, I know, but if you look up ‘refrigeration cycle’ on google/youtube, there’s some really good animations out there.

The thing to keep in mind is that the refrigerant goes around in circles. If you draw a line through the compressor and metering valve (TXV, orifice etc) you’ll split the circle into two halves. Everything from the compressor to the metering valve is under high pressure, everything from the metering valve back up to the compressor is low pressure (aka suction). Each side has a set of coils. The low pressure coils (in the house) absorb heat, the high pressure coils (outside) reject the heat.

This is the exact same way (more or less) your car AC works, your refrigerator, your dehumidifier and most anything else that uses compressed refrigerant.

For a not entirely correct comparison. Think about what happens when you spray a bottle of canned duster. The can gets cold to the touch, right. That’s because the pressure is lowering inside the can (same for the liquid coming out of the end, it’s boiling off and also cold. If you could capture all that air coming out and shove it back in the can, it would make the can hot.

So, imagine spraying all that canned air into a bag while sitting in your house. Once all the cold dissipates (that is, it’s absorbed enough heat from the house to bring it to the same temperature as the ambient air), you then take the whole thing outside and compress it back into the bottle, and let the heat dissipate outside….that’s your refrigeration cycle. You absorbed heat from the house and dumped it outside.

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