A while back, I had a tech who was having some trouble finding a 35 PSI (2.41 bar) make-on-fall pressure switch. One adjustable switch in the catalog said (SPDT), but he didn't quite understand what that meant. In that case, it means single-pole, double-throw, and the “double-throw” part means that the switch has terminals in both the […]

We may not realize it, but heat transfer inside our homes keeps the HVAC industry afloat. Without air conditioning in the summer, our buildings would remain stuffy, miserable places. That’s because heat can come from the outdoors, indoor objects (such as cooking appliances), and our bodies. So, this article will cover the three main types […]

Proper sizing and orientation of grilles, registers, and diffusers may seem like such a simple thing, but it's an area where confusion and mistakes are commonly made. First, let's define some terms. Return  A return draws air into a return duct system with negative pressure compared to the space, usually via a fixed “grille” (also […]