When you ask many people nowadays how to check the charge on a heat pump during low outdoor temps, they will say that you need to “weigh in and weigh out” the charge. While this may be an effective method, it isn't always practical. Now, if you are making a refrigerant circuit repair, weighing out […]

Fan laws and fan curves are a deep subject with a lot of nuance and variation. Just to get our heads around the subject, let's focus on two different types of fans that we see all the time in HVAC: the prop/axial type and the radial/centrifugal type. Centrifugal/Radial As we increase the pressure differential across […]

I watched an instructional video the other day where the guy kept palming his gauge manifold and CRANKING down on the valves when he closed them. I've seen techs use channel locks—and even vise grips—to tighten down their gauges “just in case” when they have a hard time finding a leak or a vacuum that […]