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 […]

You may have heard of a Western movie called True Grit. I won’t spoil it for you, but John Wayne joins Kim Darby to hunt down the man who killed Darby’s father and left with the family’s savings. (Wait, you’re telling me there’s a version with Jeff Bridges, Hailee Steinfeld, and Matt Damon? I thought […]

Travel back in time with me to 2001. I was a young tech, proving my salt out there in the big world of commercial RTU maintenance. One of the steps in the Fall PM list was “test aux heat,” and by golly, that's what I was going to do! I was on the roof of […]