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 […]

In HVAC systems, liquid and vapor will exist at the same time and place. We call that condition saturation, or we say that the refrigerant is “at saturation.” Phase changes occur in the evaporator and condenser, so these are spots where liquid and vapor coexist while the system is running. Saturated conditions occur whenever liquid […]

Note: My brother Nathan wrote this a few years back, and I only did some minor editing. A pool heat pump is essentially a water-cooled air conditioner in reverse. It usually has a large air evaporator on the outside that looks like a condenser coil and a heat exchanger (usually tube-in-tube) on the inside. A […]