The first law of thermodynamics is an extension of the law of energy conservation. The latter states that energy can be neither created nor destroyed but converts from one form to another. Thermodynamics is the study of heat’s relationship with mechanical work, and it establishes heat as a form of energy that can be neither […]

I was watching this video on the HVACR Videos channel by my friend Chris Stephens, and I was impressed by how completely he diagnoses the system both visually and with his tools. Take a look. I say this all the time, but a good, efficient technician is one who sees everything and can also quickly […]

Evaporator temperatures below 32° are common and acceptable in refrigeration; that's why there is a defrost sequence. In a heat pump running in heat mode, it's the same; freezing is a part of the process, and defrost is necessary. In comfort cooling, we can't allow the evaporator to get below 32°, or it will freeze. […]