To adequately balance a mechanical HVAC system, it is necessary to also verify exhaust flows ... set the hood to exhaust or return mode. Also, as with supply diffusers, an alternate means of measuring ...

Manual D Ductsize (MDD) is a fast and simple program designed for sizing and analyzing HVAC duct systems based on the Air Conditioning Contractors of America’s (ACCA’s) Manual D procedures. It ...

connecting the combustion air to the return air will make the system less effective.) For more information on combustion air supply ducts and purchasing a furnace or air conditioner, contact the ...