Often in commercial HVAC and refrigeration, you'll come across a sight glass/moisture indicator on the liquid line. (Oil sight glasses also exist, but those are different from what I'm talking about today.) Sight Glass The sight glass portion is simple; it's just there to show if the liquid line has a full line of liquid […]

Every now and then, a tech will call me and give me the same story of woe. They're working on a system and have the following readings: Low superheat Low suction pressure Low head pressure They'll reassure me that the system airflow is correct. So, what could possibly be wrong? I'll ask how they could […]

Refrigerant migration is a natural process that occurs during the off-cycle. The refrigerants have an affinity for oil and seek out the lowest-pressure areas, so it only makes sense that some refrigerant would be drawn to the compressor crankcase and may condense there. When the refrigerants condense, they saturate the oil. As a result, refrigerant […]