Air Conditioning in the Winter

We will begin at the compressor. The compressor is the heart of the system. It compresses the Freon. While it compresses it also pumps the Freon around and around the system like your heart. The compressor has 2 tubes connected to it. One tube is the outlet from the compressor. This tube is the smaller of the two. This smaller tube connects to the inlet of the condenser.
"Condenser" is the outside coil (unit) that has a fan on it. The condenser receives the Freon in a gas state from the compressor. The pressure is high and so is the Freon temperature. As the compressor keeps pumping, the Freon is forced to go thru the coil. As the hot Freon moves thru the coil it must be cooled down so the gas will turn into "liquid". Here is where the fan comes in. The fan draws air thru the coils. This takes the heat out of the Freon to allow it to turn to a "liquid"
Liquid Freon (refrigerant) is the KEY to cooling. Now that the Freon has traveled thru the outside condensing unit and the Freon has cooled and turned from a gaseous state to a liquid state the Freon then leaves the condenser (hot coil).
The liquid line tube is the smaller diameter tubing of the 2 lines that are connected to the unit. Also you can tell the liquid line from the gaseous line by the black insulation. The smaller tubing has no black insulation covering it.
The liquid line runs from the condenser outlet up to the air handler (inside unit). Inside the air handler is where the expansion valve or capillary tubes are. The "evaporator" cold coil is inside the air handler. The liquid line is connected to either the Xvalve or capillary tube whichever you have. These valves are like a restriction. This is the point where the low side and high side are separated.
*High Side* The tubing from the compressor thru the condenser and up to the Xvalve (restriction) in the air handler is the high side.
Now we are at the point where the cooling takes place. ***As I stated above*** the liquid is the KEY to cooling. When the liquid Freon goes thru the Xvalve it enters the "evaporator" (cold coil. The evaporator is at a lower pressure (low side).
"Low Side" The copper tubing from the Xvalve thru the evaporator and back to the compressors inlet is the low side. The compressor pulls the Freon in. This suction by the compressor along with the Xvalve (restriction) is how the lower pressure is created. If there was not any restriction in the system the Freon would just go around and around without any cooling. With the Xvalve in the system there will be a high and low side.
Back to the *evaporator* cold coil. As the high pressure liquid in the small tubing enters the evaporator the Freon will "boil" because the evaporators pressure is much lower. Its like putting alcohol on your skin, the alcohol feels cold because it is evaporating. Thats what the Freon does inside the evap.
Since the compressor is sucking in all the time it keeps the Freon changing from the liquid to a gas. As Freon changes its state back to a gas the Freon absorbs heat. So that’s where the fan comes in. While the Freon is absorbing heat the fan draws the air thru the cold coil to have the heat taken out of the air that circulates in the house. The evaporator does not cool the air; the Freon takes the heat out of the air.
Now that the Freon has passed thru the evaporator (cold coil) and absorbed the heat, the heat needs to be removed from the Freon. This is done by the compressors suction where the Freon with the heat is sucked in to the compressor from the large tubing with the black insulation. The compressor compresses the gas and starts all over again.
As stated above the compressor compresses the hot gas and sends it to the condenser (hot coil) to have the outside fan take the heat out of the Freon and turn it back into a liquid to start the whole process over again.

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