This tech tip was written by a friend of HVAC School, Brian Mahoney. He is an HVAC instructor at Western Suffolk BOCES/Wilson Tech. Thanks, Brian! The podcast on delta T for A/C the other day got me thinking about the formula I learned in school about calculating the GPM of a hydronic system. We will […]

Do you know how a solenoid valve works? Really? On the surface, I think we all understand how a solenoid valve works. The coil energizes, creating an electromagnet. That temporary magnetism lifts an iron plunger within the valve allowing refrigerant to flow. But is it really that simple? It turns out that the answer isn't […]

This article was submitted by Genry Garcia of Comfort Dynamics, Inc. It is the second part of his series on zonal pressure diagnostics. Thanks, Genry! In Part 1 of this series, we outlined the basic understanding of ZPD—what it means and what it does. Most importantly, we showed how an effort to simplify a fairly […]