The most common method to defrost appropriately in refrigeration involves both time for initiation and a combination of time and temperature for defrost termination (ending defrost). But why can't we just use temperature or time alone? (You may wonder.) Imagine a common freezer with a designed box temperature of -10°F and a coil temperature of […]

Friction rate is a value located on a ductulator. We use it during the design phase of a duct system to predict the operating static pressure of a duct system. The challenge with friction rate is that it is often misapplied by folks using a rule of thumb (ROT). In order to apply friction rate properly, […]

This article was written by boiler technician Justin Skinner. Big thanks to Justin for being one of the rare techs who cares enough to take the time to write something like this. Thank you, Justin! Pressure switches are used in a variety of applications. Generally, they are a normally open switch that closes with either […]