Tech Tips

Today's tech tip is a video put out by my friend Brad Hicks from the HVAC in SC YouTube Channel. Thanks, Brad! Seal boots to prevent raccoon leaks. Ok, this has nothing to do with raccoons, but I like that photo. Whenever you are installing duct boxes (also called boots or cans) in an aftermarket […]

“Service factor” is an interesting motor rating that you will see on many motor data tags. It simply means how much additional “work” a motor can do or how much “load” it may be placed under for short periods of time without failure or overload. For example, the FLA or full load amps of the […]

There is a common belief in the trade that the higher the subcooling, the better the system efficiency because lower liquid line temperature means less flash gas. This statement is only partially true and can lead to some confusion among techs. Subcooling is a temperature decrease below the condensing temperature of the refrigerant that occurs […]

Suction pressure, head pressure, subcooling, superheat, delta T. Taking all five of these calculations into account on every service call is critical. Even if you must do further diagnostic tests to pinpoint the problem, these five factors are the groundwork before more effective diagnostics can be done. I would also add static pressure as an […]

Travel back in time with me to 2001. I was a young tech, proving my salt out there in the big world of commercial RTU maintenance. One of the steps in the Fall PM list was “test aux heat,” and by golly, that's what I was going to do! I was on the roof of […]

If you work in large commercial offices or mixed-use buildings, you almost certainly work with VAV systems regularly. If you aren't familiar with VAV, this is a quick intro to the basics so that they won't seem so overwhelming. VAV stands for variable air volume; this means that the AHU (air handling unit) can vary […]

I was about 13 years old the first time I bent EMT with my uncle. We were doing a renovation at a church; watching him bend EMT and then getting to do it MYSELF was a truly religious experience. There are a few things in the trade where workmanship really comes into play, such as […]

This quick tip was written by Daniel Andersen in the HVAC School Group. Daniel was one of my early encouragements to make the podcast, even though he refuses to come on himself. Thanks, Daniel! ERV – What is it?  An energy recovery ventilator allows fresh air from outside to be introduced into the conditioned space […]

Because the name of the website is HVAC School, I get a lot of people who assume we either: A) Have a physical location B) Sell online courses You are probably aware by now that we do neither of those things. We are a free learning resource for anyone looking to improve their professional skills […]