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 […]

This website is for professional HVAC techs and those actively learning to become professional HVAC techs, not DIY homeowners. I feel like that needed to be said before I state these seemingly obvious facts, but these very obvious facts are so commonly mistaken that it needs to be covered. Take a look at the two […]

A good technician uses their senses before they use diagnostic tools. Is your suction line abnormally cold? Make sure the evaporator coil isn't frozen, and inspect for obvious airflow issues like a dirty filter or evaporator coil. Is your liquid line abnormally warm to the touch? It could be a dirty condenser, condensing fan issue, […]