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 […]

I used to call PTCR devices a "Soft Start". I was wrong.

Both wet-bulb temperature and air enthalpy are extremely useful to understand when calculating actual system capacity and human comfort. Dry-bulb temperature is a reading of the average molecular velocity of dry air. However, it does not account for the actual heat content of the air or the evaporative cooling effect of the air. When air […]