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 […]

Air changes per hour (ACH/ACPH) simply describes how many times the quantity of air in a room (or structure) is completely replaced per hour. If you have a 10'x10'x10′ room, the room contains 1000 cubic feet of air. If the supply and return to the room is supplying a balanced 100 CFM (cubic feet per […]

We have discussed DTD (design temperature difference) quite a bit for air conditioning applications, but what about refrigeration? Let's start by defining our terms again. Suction Saturation Temperature The saturation temperature is the temperature at which the refrigerant will be at a given pressure if it is currently changing state. This change of state would […]