In this article, we will discuss an HVAC unit’s refrigerant pressure on both the high side and the low-pressure side while the system runs. It is important to know the range of these pressures in order to understand why and how charging and recovery are performed. The first thing to realize is that when a system is off and equalized, the system’s pressures on both the high side and the low-pressure side will match. In the example of an R-410A packaged unit with a surrounding air temperature of
