This tech tip video comes from my friend Andrew Greaves of AK HVAC and HVAC Comedy on Youtube and the HVAC Vehicle Layouts group on Facebook. Many residential techs get confused when they see these multi-position valves in larger equipment, and Andrew does a great job of demonstrating the basics in this video. In 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 […]

Net refrigeration effect (NRE) is the quantity of heat that each pound of the refrigerant absorbs in the refrigerated space to produce useful cooling. That’s a pretty vague definition. We know that it’s an amount of heat in processes that take place within the evaporator. Still, the phrase “useful cooling” seems rather broad. Even though […]