In the trade, we talk a lot about changes in enthalpy, especially when we are looking at total heat exchange over an evaporator. Sometimes, you will bump into the word entropy, and I wanted to take a stab at making it more understandable. Many people understand entropy as the condition in which molecules become more […]

I was talking about dry contacts with one of my techs, and he looked at me like I had three heads—and one of them was on fire. So, I figured it would be good to cover the difference between wet and dry contacts in a tech tip. Basically, “dry” contacts are switches with no shared […]

Every now and then, a tech will call me and give me the same story of woe. They're working on a system and have the following readings: Low superheat Low suction pressure Low head pressure They'll reassure me that the system airflow is correct. So, what could possibly be wrong? I'll ask how they could […]