Why Defrost? Let's start with the basics and move on from there. Defrost is necessary when the coil temperature drops below 32°F. Defrost can be as simple as turning the compressor off for a period of time or as elaborate as reversing the flow of refrigerant for the whole system or just parts of the […]

This article is written by Sal Hamidi, founder of Productsbypros.com, an innovative manufacturers representative agency that promotes great HVAC/R products through training and media. You can reach Sal at Sal@productsbypros.com.   If we are going to discuss vacuum pump oil, it's important to understand what it is first. Most HVAC application vacuum pumps are rotary […]

In commercial HVAC, you will find several different types of multi-stage evaporator coils: intertwined (shown above), horizontal face split (one coil on top of another), and vertical (side by side). When staging a horizontal evaporator, pay attention to ensure that stage #1 is on the bottom and stage #2 is on the top. If stage […]