Air Barrier vs. Vapor Barrier vs. Insulation
Think of it like this: It's a cold, wet, windy day. You can take an umbrella to protect you from the water alone, but that won't deal with the cold (temperature) or the wind (air convection). You can add in a light windbreaker, which will help keep the wind (convection) off. But if you also […]
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Gas Furnaces – What a Tech Needs to Know
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 […]
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Dunning-Kruger in HVAC
A few years ago, a friend of mine, Clive Mitchell, aka Big Clive, explained the Dunning-Kruger concept while he was a guest on my YouTube-based podcast, “HVAC Overtime.” Clive is another content creator on YouTube specializing in technical videos where he reverse-engineers electronic devices. Clive has a very analytical mind; he sees patterns in people […]
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A Great HVAC Training Solution
DISCLAIMER: I have no financial interest in HVAC Simulator or Dirk’s company, Nauman Innovation Group LLC. He is not a sponsor; I just think he’s a great guy who cares a lot about the industry, and I’m excited to share his work with other people who want to improve training and education in the skilled […]
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Do Small Air Leaks Matter?
How do we decide what to spend our time and attention on as technicians? What is truly important and what isn’t? At least here in Texas, the answer changes seasonally. When it’s 100 degrees outside, your priorities shift from long conversations about people’s pets to conveying necessary information about system problems so we can get […]
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Why Many Techs Confuse Overload, Short, & Ground Fault
The point of this article is to give you a full understanding of the role fuses, overloads, and circuit breakers play in the protection of HVAC/R equipment. If you skim-read or jump to conclusions, you will be tempted to argue. Be patient; if you want to understand, you will need to read all the way […]
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Don’t Forget the Suction Filter Drier
Courtesy of Emerson It is important to have refrigerant free from debris and contaminants, and we control these issues on many different fronts. 1. Proper tubing handling prevents copper shavings, dirt, and water from entering while installing. 2. Flowing nitrogen while brazing prevents carbon build-up. 3. Deep vacuum of 500 microns or less removes air, […]
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Combustion Air
To maintain combustion (burning), you need three things: fuel, heat, and oxygen. If you have all three in the proper proportion, you can maintain a continuous state of combustion. Remove one (or reduce one sufficiently), and the triangle of combustion can collapse. In a common natural gas (NG) furnace, the heat is the igniter, the […]
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Tips for Server Room Conditioning
Server rooms, sometimes called data rooms, are a somewhat unique situation in the HVAC trade with some special circumstances that should be considered. Here are a few tips for success when working on equipment for these spaces. Note: this article is focused on smaller server rooms that may use conventional or mini-split-type forced air equipment. […]
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