Recovering refrigerant sounds like an easy task at first, especially with digital recovery machines and large hoses at our disposal. Unfortunately, we all know that filling the tanks is more complicated than it seems.  If you want to recover refrigerant and store it in a tank safely, you’re going to have to do some math. […]

This article is written by one of the smartest guys I know online, Neil Comparetto. Thanks, Neil! Recently, I posted a question in the HVAC School Group on Facebook that went like this: “When designing a residential duct system, what friction rate do you use?” As of writing this, only one answer was correct according […]

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. […]