The first law of thermodynamics is an extension of the law of energy conservation. The latter states that energy can be neither created nor destroyed but converts from one form to another. Thermodynamics is the study of heat’s relationship with mechanical work, and it establishes heat as a form of energy that can be neither […]

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 […]

Full disclosure: as a technician, I was guilty of setting the fan to “on” at the thermostat for many years. I never really thought of any of the negative impacts that could happen. I wanted to circulate the air and keep air moving through the high-efficiency air filter that most of our houses had. Later, I […]