Testo 760 Category IV Multimeter I was standing at a booth at the HVAC Excellence Educators conference, and an instructor walks up, grabs a meter, and asks me, “What's the difference between a category 3 and a category 4 meter?” Well, I really wasn't sure, but I knew that the category 4 meter is rated […]

  Illustration Courtesy of Emerson CO2 is a pretty nice refrigerant. It has zero ODP (ozone depletion potential) and a GWP (global warming potential) of 1. CO2  has been used as a refrigerant almost from the very beginning of refrigerants, and it's been making a big comeback in market refrigeration (especially in colder climates). CO2 […]

This article was written by Michael Housh, owner of Housh Home Energy and a regular contributor to HVAC School. Thanks, Michael! This is another article in trying to relate the air side of HVAC with the water side. In this article, I’m going to talk about how to determine pump flow (GPM) based on the […]