Why Defrost? Let's start with the basics and move on from there. Defrost is necessary when the coil temperature drops below 32°F. Defrost can be as simple as turning the compressor off for a period of time or as elaborate as reversing the flow of refrigerant for the whole system or just parts of the […]

How an A/C System got to be Oversized (Maybe) But My Old Unit Worked Fine?! Most of us have heard this at some point. This complaint typically comes from a particularly unhappy customer after the installation of a brand new A/C system. Throughout this article, we’re going to explore the possible root causes of this […]

My good friend and contributor to HVAC School, Neil Comparetto, made this video showing how he creates access ports for static pressure and gas combustion analysis. As techs, we find ourselves in the tough position of needing to drill access holes to take measurements, but the drilling and sealing of the holes can sometimes create […]