Tech Tips

This article is based on the recent HVAC School podcast episode on A2L refrigerants with Jason Obrzut. You can listen to that podcast HERE. Jason is a member of the AHRI Safe Refrigerant Transition Task Force and has co-authored Refrigeration and Air Conditioning Technology (the RACT manual). You can access AHRI’s A2L refrigerant resources at […]

Technicians have to make flare fittings in the field every day. Most of the time, the application is for mini-split/ductless installs. However, you may encounter certain situations where flared fittings are more practical than a braze joint. Regardless of the reason, flared connections are notorious in our trade for being popular leak areas. Either the flare […]

Swaging copper is one of the most common practices in our trade when it comes to brazing pipes. Yes, it sometimes makes more sense to slap on a coupling or street ell fitting, but most of the time, cutting your braze joints in half is much easier and faster during an install or repair.  So, […]

This topic came up because I was testing out the new MR45 digital recovery machine. That machine goes off by itself when it hits a 20″ Hg vacuum. It's a cool feature, but it is good to know when that level of vacuum is overkill and when it's not enough according to EPA requirements. You […]

Take a look at the screenshots above. The one on the left is for Death Valley at 282′ below sea level, and the one on the right is Denver, CO, at 5,280′ above sea level. Notice the barometric pressure values; they are almost the same. That means that barometric pressure is corrected or “normalized” to […]

  In this 60-second tech tip video by Brad Hicks with HVAC in SC, he shows us how and why to remove the weep port plugs on a condensing fan motor. I know from experience that motors can fail prematurely when this practice isn't followed. Remember that motor orientation dictates which weep port plugs are […]

The definition of a transformer is a device that changes the voltages in an alternating current circuit. You may have heard of an autotransformer or a buck-boost transformer, and these terms are usually used for the same type of device; they just highlight different aspects. A transformer does not need to be a buck-boost to […]

In order to wrap my head around diagnostic issues, it helps me engage in thought experiments where I think of more extreme examples of an issue or situation or consider the ideal to find the “edges” of a concept. Once I find the extreme edges, I can begin to sort down to a more exact […]

DISCLAIMER: HVAC School is NOT an official OSHA safety training resource! Although we provide safety tips in good faith, our website is not a substitute for safety training from an authorized OSHA training source.   Let’s be honest: most of us probably got into the HVAC trade because we enjoy working with our hands. Unfortunately, […]