Proper sizing and orientation of grilles, registers, and diffusers may seem like such a simple thing, but it's an area where confusion and mistakes are commonly made. First, let's define some terms. Return  A return draws air into a return duct system with negative pressure compared to the space, usually via a fixed “grille” (also […]

  We've all heard about glide, but what is it really, and how does it affect our system? Glide, or temperature glide, is the difference between the bubble point and the dew point of the zeotropic refrigerant mixture. Well, that wasn't very helpful, was it? All we did was introduce new terms without defining them, […]

I got in one of these tiny torches the other day to experiment with brazing aluminum in tight spots, and one of the techs walked in and asked, “What type of torch is that?” I answered, “It's oxy/acetylene.” He picked it up and looked at it a bit, then asked, “Does that get hot enough […]