While there is no such thing as too much return air for the equipment (actually, there is, and it causes fan cavitation, but very rare), this CAN be an issue for the house. It has the potential to throw off pressures in different areas of the house.Click to see full answer. Herein, what size should a return air duct be? Duct Size – Single Return As for any duct, size is dependent on duct length, air flow, and allowable static pressure drop. For most systems, the minimum duct size (see Table 1) is sufficient for up to 25 feet (8 m) with no more than three 90° bends.Similarly, what happens if ductwork is oversized? A larger duct is going to hold more air and therefore the furnace fan will have to work longer to push all of that air out until the newly heated or cooled air is actually what’s being pushed into the room. Yes! If your duct work is not sized correctly you will not get the right flow of air to each room. Moreover, can air return too big? While there is no such thing as too much return air for the equipment (actually, there is, and it causes fan cavitation, but very rare), this CAN be an issue for the house. It has the potential to throw off pressures in different areas of the house.Should return duct be larger than supply?Return ducts are always larger than supply trunks. 3. Supply air and return air is always equal because its a closed loop system to the equipment.
