Tech Tips

  Flowing nitrogen while brazing and pressurizing with nitrogen are great practices. Putting nitrogen in with the refrigerant? Not so much. Nitrogen is a “non-condensable” gas because it cannot be condensed (under normal conditions). However, nitrogen is just one of the non-condensables. First, let's talk about what a non-condensable gas is. Any gas that does […]

First off, if you've never heard the term “beer can cold,” you are either not in the trade, or you have been living a pretty sheltered existence. I started as a tech apprentice when I was 17 years old, and on my first day in the truck, my trainer grabbed the suction line of a […]

Photo by Stephen Rardon I hear it all the time. Someone will talk about undesired condensation on an air handler cabinet, on a supply air duct, in a ventilation duct, or on a vent like the one above. In reply, someone will inevitably say, “Condensation occurs where hot meets cold.” Early on in my career, […]

Graphic Courtesy of Danfoss On 8/8/17,  the United States court of appeals struck down an EPA phaseout of HFC refrigerants under the Clean Air Act on the basis that the Clean Air Act only gave the EPA the right to regulate ozone-depleting substances. However, many of us figured that the decision was likely to be […]

Spring and fall are the seasons where all service technicians get turned into janitors. Some techs see this as a chore and don’t particularly enjoy the routines of checklist maintenance. However, it is important to remember that the “shoulder seasons” provide an opportunity for us to perform vital maintenance on systems in order to keep […]

I was fresh out of school, working as an apprentice at my first real HVAC job, and I was listening in on a shop conversation between a few techs. They were talking about finding so many overcharged systems. One of the techs turns to me and says, “I had a unit yesterday that was so […]

Over the years, I have heard technicians say that refrigerant can wear out or “lose its blend” by sitting in a tank. Refrigerant does not wear out or “lose its blend”… at least not like that. What can and does happen is called “fractionation.” Refrigerant blends are composed of a mix of refrigerants with different […]

When brazing and soldering, we have a few things we need to accomplish to make a proper connection: We can't overheat the joint until it overheats the base metal or the flux where applicable. We must bring the entire joint above the melting temperature of the brazing alloy. Draw the alloy deep into the joint. […]

If you are new to the trade, I'd like to welcome you. Like many skilled trades, the HVAC/R trade has many opportunities and can help you make a good living. If you are young and new to the trade, we need you. We are grateful to have you. However, if you aren't thoughtful, you might […]