Probably the most popular measurement method for indirect airflow readings is total external static pressure (TESP). A dual-port manometer or two Bluetooth single-port manometers are essential to the HVAC technician toolbag. Here’s a quick review of TESP, why it’s important, and how to make the measurements. TESP is a pressure reading of the “balloon” pressure […]

Go to your truck, pick up a contactor, and look at it closely. You may find some interesting ratings you never noticed—things like terminal ambient temperature ratings and torque specs. One reading you may overlook is the RES AMPACITY of the contactor or relay. The RES rating is the RESISTIVE LOAD AMPACITY (amperage capacity) or rating. […]

We all see a lot of questions about dyes, leak stoppers, lubricants, inhibitors, and snake oil. All of those were designed to go into the refrigerant circuit and “improve” something. I just go back to what Ray Johnson always said. (Ray is one of my early heroes in the biz, and he taught me a […]