Tech Tips:

Should I Pump Down or Recover?
By:Matthew BrunerDuring my second year in HVAC, the company I worked for was hired to fix some poor work that was done on a multi-head inverter system. The system used flare connections, and many of them were leaking. The system also had a branch box, which meant there were even MORE flares. So we pumped […]
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Two Tips for Tough Vacuum Jobs
By:Matthew BrunerIn the last year or so, I have had a couple of puzzling experiences related to pulling a vacuum. These instances have left me with questions and clues where I thought I had given up on understanding a certain vacuum situation. Typically, if I’ve had a hard time achieving a proper vacuum, I would […]
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Start Flowing Nitrogen Sooner
By:Bryan Orr My technician (and brother-in-law), Bert, made a good point. (It's hard for me to admit it, but it's true.) When he needs to open the refrigerant circuit to make a repair, regardless of whether he is recovering or pumping down, he pulls out his nitrogen tank and his regulator. (We like the Western […]
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By:Bryan Orr   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 […]
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Sweeping with Nitrogen
By:Bryan Orr Two days prior to this article being published, I sent one out about the popular fallacy that nitrogen “absorbs” moisture. That tech tip went out at 7 PM eastern time like usual, and I was sitting on the couch watching something on the Food Network (as usual). At 7:10 PM, I get a […]
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Does Air or Nitrogen Absorb Water?
By:Bryan Orr There are many examples of teaching using metaphors to help someone grasp how something works without being EXACTLY correct. Some examples are how we often use water flow to explain electrical flow or refrigerant circuit dynamics. It's enough like the way it works to get our heads wrapped around it, but there are […]
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How (and Why) to Flow Nitrogen While Brazing
When I started in the trade, the idea of flowing nitrogen while brazing was nothing more than the punchline of a joke. Like pulling a vacuum with a micron gauge or proper recovery, it was a wink and nod proposition rather than a real practice. I've had to unlearn many bad habits since those early […]
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Triple Evacuation and Nitrogen FACTS
By:Jeremy Smith This article was written by longtime contributor and RSES CM Jeremy Smith. Thanks, Jeremy! Nitrogen doesn’t absorb moisture like many techs think that it does, and I think that we, as technicians, need to reevaluate the reasons for the “triple evacuation” process. OK. Hold on, now. Put down the pitchforks and torches, and […]
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Is Flowing Nitrogen While Brazing Really Important? – Live Video 2/4/2017
In this live video Bryan talks about Flowing Nitrogen Reasons techs give not to flow nitrogen Reasons that some cases create more carbon than others Demonstration video by Tim Bagnall
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Things to Keep out of the System – Class
By:Bryan Orr  This podcast is a class taught by Bryan: Things to Keep Out of the System. He covers some installation best practices along the way to keep contaminants and non-condensable gases out of the system. We want to keep air, water, dirt, copper shavings, solvents, and nitrogen out of an operating system. All […]
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Flow Nitrogen Great Again
By:Bryan Orr In this episode of the HVAC School Podcast, Bryan talks with Tim Bagnall about flowing nitrogen. Many techs don't flow nitrogen. Some may say that it is overkill, but it has been shown that flowing nitrogen displaces oxygen while brazing and prevents harmful scale from forming on the copper. Scale is very problematic, and it […]
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