Tech Tips

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.   When most people think about respiratory devices, their minds probably jump to soldiers wearing gas masks in warfare, hazardous waste […]

I got this question via email (edited slightly for length): Some things I've done because I've been taught to do them yet I don't know why I do them. One of those things is putting a jumper between w1/e and w2. Sometimes, in the case of a Goodman for example, I've been taught to combine […]

Many of us understand that we need to get involved in local trades education to prepare students for fieldwork and get more people to consider careers in the trade. One of the ways contractors can support educators is by getting involved with local trade schools and industry organizations. We can do that by attending meetings […]

One of my most popular YouTube videos goes over how to adjust TXV superheat. It's a very simple little video that I did at my desk, and the other day I got this comment: “Good Video but I hate to say this BUT, with the title SCHOOL, why would you show the public an instructional […]

Commissioning a system is critical anytime a technician makes any type of repair or alteration to an existing system. It’s also important if you’re working on a system you’ve never worked on before, and it’s a vital part of a new install start-up. Basically, commissioning systems is an everyday responsibility for technicians, which means everyone […]

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 […]