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This is a basic overview of the HVAC/R refrigerant cycle (and refrigeration circuit) and how it works. It isn’t a COMPLETE description by any means, but it is designed to assist a new technician or HVAC/R apprentice in understanding the fundamentals. First, let’s address some areas of possible confusion:  1. The word “condenser” can mean […]

I teamed up with Ty Branaman to design an intuitive way for techs to solve some of the “what should it be?” questions in the HVAC field.  The topic for this sheet is subcooling (or subcool). Subcooling is a measurement of the temperature DECREASE of a liquid below its saturation (mixed liquid/vapor) temperature at a […]

My goal in this tech tip is to help those who struggle to understand heat pumps get their heads around them as quickly as possible and understand some of the things a tech needs to know about them. The basic idea of a heat pump is to use the compression refrigeration cycle to move heat […]

This is the article you read BEFORE you call and ask a senior tech what your subcooling should be. It’s also the one you send to a junior tech when they call and ask you: So, what is subcooling? (Or subcool, as many call it.) Subcooling is a measurement of the temperature DECREASE of a […]

Florida’s got a lot of great qualities: some pretty neat wildlife, beaches all around, and theme parks. On the flip side, Florida also has hurricanes and a lot of humidity. As much of a pain as it might be for residents and contractors alike, humidity is one of my favorite topics. We see relative humidity (RH) […]

It can be useful to think of a multimeter as a “voltage drop” tool. Bryan covers the concept here in an excellent class that I highly recommend. This concept was a big help to me as I began to truly learn how to use a multimeter.  A meter reads the voltage differential between two points. […]

It’s that time of year again—the furnace service calls are peaking. It’s a good idea to crack open Jason Obrzut’s book, Gas Heating: Furnaces, Boilers, Controls, Components, and listen to the many public podcasts and presentations by experts like Jim Bergmann. At HVAC School, we’re fortunate to have had some of the industry’s greatest minds […]

A refrigerant is anything we use to move heat from one place to another using the compression refrigeration circuit. However, the history of refrigerants and the different kinds is quite diverse and interesting. Have you ever noticed how your skin feels cool after you apply some rubbing alcohol to it? For a long time, scientists […]

We’ve all been new at one time or another. So, there is no need to get all judgy about some of the mistakes new techs make just because they are inexperienced. However… These are some very preventable mistakes that occur due to simple oversights and carelessness that need to happen 0% of the time. 1. […]