The year was 1774, and a man named Tom traveled the Atlantic from England to visit his friend Ben in Philly. Tom was 37 years old, and he had already been through a failed business and lost his wife and child during childbirth. He was a troublemaker by some accounts—a free spirit at the very […]

I was talking about dry contacts with one of my techs, and he looked at me like I had three heads—and one of them was on fire. So, I figured it would be good to cover the difference between wet and dry contacts in a tech tip. Basically, “dry” contacts are switches with no shared […]

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 […]