Tech Tips

This article was submitted by Genry Garcia of Comfort Dynamics, Inc. It is the final part of his series on zonal pressure diagnostics. Thanks, Genry! Updated 3/4/2022 Picking up where we left off in part 2 of the series, we discussed how a pressure reading from an attached zone indicates only the ratio of the […]

Our industry puts a lot of emphasis on the “AC” (air conditioning) part of HVAC. We specialize in maintaining and servicing a wide variety of simple to complex air distribution systems. But we’re really in the business of comfort—human comfort and health, to be precise. So, just how much does the human body rely on […]

I have been teaching at my local trade school as an HVAC instructor for the past year. It’s been a much different experience than training a technician on the job. Some of the students are already working in the field, and others have never been in an attic or crawl space. But regardless of experience […]

This article was written by Tim De Stasio with Southern Comfort Consulting and Service. It was originally published on his blog, which you can access by clicking THIS link, but he permitted us to republish it on HVAC School as well. Thanks, Tim! It is critical for an HVAC technician to understand airflow and how […]

Let's use a bit of imagination for a minute. Imagine you have two totally identical 3-ton systems. One of them is completely normal, and the other has no fins at all on the evaporator coil. They both have the same charge, airflow, and compressor capacity. What will be different in terms of readings and performance […]

This article includes significant contributions from Neil Comparetto and Brian Chadwick, both of whom are HVAC technicians in Virginia. Brian is also the owner of Chadwick Air, and Neil is a co-owner of Comparetto Comfort Solutions and a longtime contributor to HVAC School. Thanks, guys! DISCLAIMER: A lot of the information in this article is […]

There was a question in the Facebook group a few days ago about averaging sensors. There are two common configurations/methods used for averaging. The first is simply a setting in a thermostat or control where it reads separate sensors, and then the thermostat itself averages out the readings using its software. For example, if the […]

I recently received a message asking for a discussion of relative humidity (RH), wet-bulb (WB), and dry-bulb (DB). Time and time again, I hear techs say that condensation occurs when “hot meets cold,” which may be true in some cases. However, that is only a shorthand way to describe it and doesn't really address what […]

This article was written by Sam Myers with Retrotec. Thanks, Sam! If you’ve ever lived in a historic home, you’ve likely noticed that the level of comfort can change throughout different parts of the house. It can also typically change throughout different times of the year, depending on your climate. That is primarily due to […]