With new home construction, good ductwork design must begin with the blueprints for greatest energy efficiency, heating and cooling performance, and uncompromising comfort year after year. Follow these duct-design principles to maximize your investment.Principles of good ductwork design Balanced air flow throughout your home involves equal air movement through the supply and return ducts, which is made possible by correct duct sizing, location and sealing, and an unobstructed pathway for air circulation from registers to grilles.If these criteria are not met, problems often develop, such as pressure drops at the air handler, extra work for your heating and cooling systems, and moisture accumulation in walls, ceiling and/or floors that invites mold growth.
To correctly size your new duct system, Manual J and D by the Air Conditioning Contractor of America must be used. Manual J is used to calculate heat gain/loss for each room of your home. With the measurements for heating and cooling requirements in hand, your HVAC professional uses Manual D to design the size and layout of your ducts.
It’s important where ducts, registers, grilles and the heating and cooling systems are located in your home. The heating and cooling systems should be in a central location to allow for shorter, straighter duct runs. Registers and grilles should be installed on inner walls, preferably with a return grille in each room that contains a supply register. To minimize heat loss (wasted energy) through duct walls by conduction, ducts should be installed in conditioned areas like sealed chases, suspended ceilings, corners of rooms and raised floors. Utilize Y-branches for run-offs rather than T-branches for efficient air flow.
Properly sealing ductwork is an essential component for good ductwork design. Mechanically seal metal duct joints with screws and mastic sealant. Mastic sealant and compression straps are used to seal flex ducts. Install an expansion collar at the trunk and plenum to minimize stress and noise.
If you have questions about good ductwork design, please contact Air Assurance. For more than 30 years, we've provided top-quality service and installation for the Greater Broken Arrow area homeowners.Our goal is to help educate our customers in the Tulsa and Broken Arrow, Oklahoma area about energy and home comfort issues (specific to HVAC systems). Image courtesy of Shutterstock