How Long Should I Evacuate a System?
This article was written by Jim Bergmann with MeasureQuick. Anyone who has ever picked up a vacuum pump has asked or been asked this question. To be truthful, it is like asking, “How many licks will it take to get to the center of a Tootsie Roll Tootsie Pop?” In the words of the wise […]
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Hyperion Troubleshooting
This article was written by my good buddy, Bill Frisbie. Bill is a service manager and crack technician at AirFx, a Trane dealer in lovely Inverness, Florida. Thanks, Bill! One of the most intimidating things in the field is to walk up to a piece of equipment that you have either never worked on or […]
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Tunnel Vision and How to Avoid It
How many times has the following situation happened to you? You're on your way to that final service call. While you're listening to the customer explain their complaints over the phone, there's this precise moment where you've thought: “I know what it is already. This will be a quick one.” Sometimes, intuition proves to be […]
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Stacking Evaporator Coil Stages
In commercial HVAC, you will find several different types of multi-stage evaporator coils: intertwined (shown above), horizontal face split (one coil on top of another), and vertical (side by side). When staging a horizontal evaporator, pay attention to ensure that stage #1 is on the bottom and stage #2 is on the top. If stage […]
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Equipment Grounding
The grounding and bonding process is important, and it's a fairly broad topic. In HVAC/R, we generally just need to make sure that we properly connect the conductors (wires) provided to the proper connection points in the equipment and occasionally the disconnects. These connection lugs or green screws are rated for grounding so long as […]
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Duct Leakage Can Be Costly
This tech tip was written by one of the best all-around HVAC minds out there: Neil Comparetto. I think that we all can agree that duct leakage is not ideal. Our job is to condition the space. If we can’t control the air, that becomes difficult. On top of that, anytime the ducts leak, you […]
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Ideal Gas Rulebreakers
Breaking the Sound Barrier So, what do you think of when you hear an “ideal gas?” R22, R12 maybe… natural? Take a look at the F-18 above. It's breaking the sound barrier, and that cloud is a shockwave. It has nothing to do with this article, but I think it's pretty darn cool! An ideal […]
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Get an EEV Open (Like Magic)
This tech tip comes from our contributor, compressor decapitator, and super tech Ulises Palacios. Many ductless systems and some high-efficiency unitary systems have electronic expansion valves. If you find one that is stuck closed, you may be able to get it open temporarily by putting a strong magnet like the one shown above on the […]
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What Does “Air Free CO” (Carbon Monoxide) Mean?
  Almost everyone knows that CO (carbon monoxide) is really nasty stuff and nothing to play around with. Humans will often begin exhibiting symptoms of CO poisoning at 200 ppm (parts per million) of CO in a space. Studies have also shown that the effects of CO exposure can accumulate over time, resulting in health […]
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