The amount of pressure you're under depends on where you live. I live in Florida, so I'm very close to sea level. Therefore, the weight of the atmosphere is exerting exactly 14.7 pounds per square inch (PSIA) of pressure on every surface in every direction. There is no such thing as negative pressure—only pressure lower […]

This article was written by longtime contributor and RSES CM Jeremy Smith. Thanks, Jeremy! Nitrogen doesn’t absorb moisture like many techs think that it does, and I think that we, as technicians, need to reevaluate the reasons for the “triple evacuation” process. OK. Hold on, now. Put down the pitchforks and torches, and give me […]

There are three reasons why I don't like infrared thermometers for many HVAC tasks. #1 – The laser can be misleading The laser dot is just a point of reference, not an exact point where it is reading. Often the thermometer will read lower, higher, or over a MUCH wider area. Unless you are right […]