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 […]

We have discussed DTD (design temperature difference) quite a bit for air conditioning applications, but what about refrigeration? Let's start by defining our terms again. Suction Saturation Temperature The saturation temperature is the temperature at which the refrigerant will be at a given pressure if it is currently changing state. This change of state would […]

We may not realize it, but heat transfer inside our homes keeps the HVAC industry afloat. Without air conditioning in the summer, our buildings would remain stuffy, miserable places. That’s because heat can come from the outdoors, indoor objects (such as cooking appliances), and our bodies. So, this article will cover the three main types […]