This article is an extension of HVAC School’s “How to Measure Gas Pressure” video. Additional input was provided by Jim Bergmann. Bubble test procedures and standards were provided by Honeywell. Links to source materials are available at the end of this article. If there’s one complaint that HVAC techs should never take lightly, it’s a […]

Although there are various line lift, sizing, and trapping guidelines depending on oil and refrigerant type, there is one guideline we can all understand easily and remember to apply. This guideline is to slope suction lines towards condensing units/compressors. Keeping the suction line sloped toward the compressor, especially with long overhead lines, helps return the […]

This article deals heavily with entropy. Entropy is not a simple topic, so we highly recommend checking out HVAC School’s Entropy in Refrigeration and Air Conditioning for some background information. Describing isentropic compression is a daunting endeavor. We all recognize the term compression, and I’m sure most of us can deduce that isentropic has something […]