This photo is of a blower door test we performed at my own house using a Retrotec blower door. You will notice the 15-passenger van outside the window, which is a dead giveaway. A blower door is used to measure the tightness of a building and is often discussed in terms of an ACH50 number. […]

When you first start checking your supply air with a thermo-hygrometer, you may notice that the relative humidity is REALLY HIGH. Often, the RH in a supply duct will be between 85% and 96% relative humidity on a system that is functioning as designed. The reason for this is fairly simple: In order for dehumidification […]

Here's the first question: Does it really matter if the speed taps on a motor are run or common? Well, yes… sort of. In some cases, it helps to identify if you're dealing with an open winding or an open thermal overload. The thermal overload breaks common, but you will still read a path between […]