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 […]

Before we get into the parts that will ruffle some feathers, let's talk a bit about what a “Start” capacitor is and what it does. First, let's review that both start and run capacitors connect between the leg of power opposite of compressor common and the start winding. Even though it seems like a run capacitor […]

This tip comes from market refrigeration and controls technician Kevin Compass. Thanks, Kevin! A little tip when changing liquid cores: If you start pumping them down, begin bypassing discharge gas into the shell to warm it up, push out the remaining liquid, and bring the shell above the dew point so that it doesn't sweat […]