What should the delta T (ΔT) be? What do you mean!? 20 degrees, of course! We are referring to the air temperature drop across an air handling unit or evaporator coil in cooling mode. Actually, depending on who you ask, the answer will range between 18-22 degrees Fahrenheit. Heck, I’ve heard some insist that […]

This article is the second in a 5-part series by Senior Refrigeration and HVAC tech Jeremy Smith.  The Ground rules I've spent some time thinking about troubleshooting and the processes and procedures that I use to find problems. Not the “why isn't my air-conditioner running?” problems, but the “Things just aren't quite right”-type problems—the really […]

Every HVAC/R tech needs an electronic leak detector nowadays, and with low-GWP HFC and HFO refrigerants getting more and more commonplace, every HVAC/R tech needs a VERY sensitive electronic leak detector. (Yes, electronic leak detection does work.) We often see three types, but let's toss out the corona discharge leak detector right off the top. […]