This article was inspired by an email we received from a viewer of our HVAC School YouTube channel, Jim Holbrook. Thank you, Jim! Disclaimer: This article is written to help educate you and hopefully save lives. We are NOT an authority on the topic. OSHA, as well as company best practices and risk assessments, should […]

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. […]

Suction pressure, head pressure, subcooling, superheat, delta T. Taking all five of these calculations into account on every service call is critical. Even if you must do further diagnostic tests to pinpoint the problem, these five factors are the groundwork before more effective diagnostics can be done. I would also add static pressure as an […]