What line on the ac unit is the low side and what is the high side?

Answer 1

The high side of an a/c is as follows: The compressor ,the capillary( the capillary is a very narrow tube with an inside diameter about the size of a pencil point. )The cap tube is factory sweated to the return line from the evaporator to cool it down. As soon as this cap tube reaches the coil of the evaporator, the tube is much larger in diameter. This causes the freon to expand and it changes from a gas to a liquid. It is very cold and starts to attract warmth from the room. You will notice a small frost line which will rapidly melt because the freon used in an a/c boils at a lower temperature than the freon in a refrigerator. This sweating will continue to cover more of the evaporator, which is the low side because the pressure drops. When it reaches the evaporator, as the freon leaves the evaporator, it enters the suction line. It then goes back to the compressor where it is pressurized back through the cap tube again. This cycle is repeated again and again. So on the high side,, you have the compressor and the capillary tube and on the low side the evaporator and the suction line. It sounds complicated, but is really a very simple continuous cycle at a very fast speed.