There are major parts to a split air-conditioning system, the central heating and cooling units.
REFRIGERANT, also known as FREON or COOLANT, is a material that is mixed together to form a cold substance that is used by an air conditioner to absorb heat from the house and transfer it outside. The refrigerant is circulated between the (central heating and cooling units) the outside and inside unit by the compressor of the outside unit, which is essentially a pump.
The fan on top of the unit, when it’s running it sucks air from the sides then pushes it out through the top. As it’s doing that, the air that goes by the coils is actually cooler than the refrigerant inside the pipes so the refrigerant ends up cooling off, or giving up some its heat into the air, that’s why oftentimes when you put your hand on top of a running air conditioner, the air coming out on top is hot.
The refrigerant cools down and returns inside the home after passing through the outdoor coil. But before it returns inside the house, there’s a metering device, which is a little hole that forces all the refrigerant to pass through. The metering device is effectively doing the opposite by depressurizing it or lowering the temperature, bringing the refrigerant back to a cold temperature, and then repeating the cycle.