All fuel-burning appliances require oxygen to burn. They require sufficient oxygen to burn clean and safe, without soot and CO (carbon monoxide). I live and work in Florida, where most of our fuel-burning appliances are 80% efficient with open combustion that utilizes air and oxygen from the space for combustion. With these low-efficiency appliances, whether […]

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 […]

This is a subject that even many commercial guys don’t have to consider. For the majority of equipment, even refrigeration equipment, all that is required for proper oil return is to size the suction line properly, trap the suction line as needed, and allow for proper slope towards the compressor. Then we get into larger […]