Tech Tips

All fuel-burning appliances require oxygen to burn. They require sufficient oxygen to burn clean and safely, without soot and CO (carbon monoxide). I live and work in Florida, where most of our fuel-burning appliances are 80% efficient with open combustion. (You can learn more about the basics of combustion on a podcast with Benoit Mongeau.) […]

I knew a tech when I was just starting who was hands down, no questions asked, the best technician at the company I worked. EVERYONE, we are talking over 60 techs… we all knew it. His name was Mike Gilford. Being the little brown-nosing ladder climber I was, I made a complete study of Mike […]

There are two camps I've run into regarding cracked heat exchanger diagnosis. There are those who look for it everywhere and those who dismiss it and never look. I will start by saying that everything I write here is my own opinion and experience. Because this is such a hot-button topic, don't take my word […]

Belly band crankcase heater When I first started in the trade as an apprentice, we worked on many Trane heat pumps that used crankcase heaters. These crankcase heaters slid into the compressor sump on the big orange Tyler reciprocating compressors. They looked like the one in the picture below. It was very common for these […]

Microchannel is a coil type used in many evaporator and condenser coils. You can easily identify it by its flat tubes, and its fins look like waves between the tubes. The technology was developed for use in the automotive industry and is used for radiators and automotive A/C condenser coils. These coils are made of […]

We've all heard some version of the phrase “heat rises,” but is that really true? First, we need to remember that heat is energy, not matter. Heat is a force, not a thing. So, while heat may result in changes to matter (stuff), it isn't matter itself. When we add heat to stuff, the molecules […]

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 […]

Sometimes, we can focus on the more complicated aspects of a system and parts installation—like evacuation and flowing nitrogen—and forget the simple and critical common-sense steps to keep contaminants out of the system. One of these is pre-cleaning the tubing and connection before cutting or unsweating. For example: If you are replacing a coil, use […]

The photo above is of a real condenser coil we cleaned. The outer fins looked OK, but dirt and lint were packed deep inside. We also had sky-high head pressure and condensing temperature; those are telltale signs of an impacted condenser. That situation illustrates that a coil can sometimes look OK at first glance but […]