Tech Tips

Deburring copper tubing (often called reaming) is the practice of running a blade around the inside of tubing after you cut it to remove the burr edge from the inside. It's an important practice and should be performed whenever possible. Deburring reduces turbulence inside the lines, as burrs can cause turbulence.   HOWEVER… YOU MUST […]

This photo is of a blower door test we performed at my own house using a Retrotec blower door. You will notice the 15-passenger van outside the window, which is a dead giveaway. A blower door is used to measure the tightness of a building and is often discussed in terms of an ACH50 number. […]

Testo 557 vacuum gauge and Appion core removal tools shown I've had a change of heart. Back in the early 2000s, during the big construction boom, I did many system startups on residential units for a large company I worked for. When installers ran the line sets prior to startup, they weren't always very careful […]

We already know that oxy-acetylene torches have a lot of safety considerations attached: don’t oil regulator threads, bubble-test your hoses, you get the picture. But there’s one more we haven’t really covered: the 1/7 rule (or 1/10 rule, based on the latest industry guidance).  This commonly cited rule reduces the likelihood of flammable acetone coming […]

When sealing ductwork or repairing HVAC insulation, the tape you choose dictates the long-term integrity of the system. Temperatures fluctuate wildly in attics and mechanical rooms,  and the tape must be able to withstand these environments without degrading. To better understand how different professional-grade adhesives actually perform under elevated temperatures, we decided to put them […]

Oxy-acetylene torch tip manufacturers publish charts that tell us the ideal applications for each tip size, which is quite useful on its own. After all, a small tip may be great for a ⅜” liquid line but would hardly make a dent in 2” commercial refrigeration piping. But we can also take the information from […]

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 […]

We’ve all probably been in this situation before (maybe in both people’s shoes at different points of our careers): A technician is on the job with their apprentice. The technician tells the apprentice where the probes go on the service ports and exactly what the superheat and subcooling are.  The apprentice’s eyes glaze over, and […]

Even if you're not a market refrigeration tech, we all know that the primary function of refrigeration is to keep food cool. Easy, right? Even though food storage sounds pretty simple, there are a lot of things we should keep in mind when we think about food safety and quality. There’s a lot more to […]