Every auto A/C system is divided into sides. There are the liquid and vapor sides of the system, and there are also the high and low sides of the system. The high side or high pressure side of the A/C system is commonly referred to ad the discharge side because it starts at the A/C compressor where the refrigerant is compressed and discharged to the condenser.

The discharge or high side of every A/C system includes the discharge side of the A/C compressor, the A/C condenser and the liquid line that connects the A/C condenser to the expansion valve. The inlet of the expansion valve or orifice tube is the end of the high side of the system.

Also understand that depending on overall A/C system design, the system could include a liquid line receiver drier. Those are typically located on the liquid line and in some cases, actually mounted to the condenser.

When the A/C system is properly operating, the discharge side of the system contains high pressure, high temperature refrigerant. Pressures of that refrigerant will vary depending on the ambient air temperature of the day as well as the amount of relative humidity in the air. But typically, the best rule to follow is that under normal operating conditions, high side pressures will range between 2 and 2 and one half times the ambient air temperature when expressed in degrees F.