Tech Tips

This article is written by tech and business owner Genry Garcia from South Florida. I met Genry at a Solderweld demonstration, and he later offered to write this excellent article. Thanks, Genry! Though dehumidifiers have increased in popularity, thanks in part to the implementation of new building codes, they have become a kind of red-haired […]

This article is written by Sal Hamidi, founder of Productsbypros.com, an innovative manufacturers representative agency that promotes great HVAC/R products through training and media. You can reach Sal at Sal@productsbypros.com.   If we are going to discuss vacuum pump oil, it's important to understand what it is first. Most HVAC application vacuum pumps are rotary […]

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 […]

Does heating the air cause the humidity in the air to decrease? Yes and no. Heating air causes the RELATIVE humidity percentage to decrease, but it does not change the overall moisture content in grains of moisture per lb of air. Many old-timers will swear a blue blaze that oversizing a furnace will directly result […]

I was listening to someone talk about air relative humidity the other day while looking at a psychrometric chart, and he commented that the chart ends down at freezing (32°F) because “all the water freezes out of the air at that point.” I think I made this Jed Clampett face: The psychrometric chart is designed […]

This article was written by my buddy and Canadian Supertech Tim Tanguay. Thanks, Tim! This P/E chart shows R410a at 100°F saturated condensing temp, 10°F SC, 40°F saturated suction temp, 20°F SH at the compressor. The green highlighted thumb shape is the saturation zone. Everything that occurs in the saturation zone is a latent (change […]

I hear many techs complain about the finicky and ineffective nature of electronic leak detection—so much so that some claim that it is a waste of time altogether. We recently located a leak inside the fins of a ductless evaporator coil—pinpointed to an exact spot—using an electronic leak detector. For demonstration purposes, we took that […]

Now is the part where we get specific about start capacitors and inrush. If you haven't read the first three parts, please do so before reading this one, or it may not make sense. (You can find Part #1, Part #2, and Part #3 at these links.) I'm going to come out and say it […]

Before we get into the parts that will ruffle some feathers, let's talk a bit about what a “Start” capacitor is and what it does. First, let's review that both start and run capacitors connect between the leg of power opposite of compressor common and the start winding. Even though it seems like a run capacitor […]