Duct system design is important for three reasons: optimal energy savings, greater home comfort and less burden for your heating, cooling, and ventilation systems. Unfortunately, the average homeowner loses 20 percent of energy efficiency with faulty ductwork, and never fully achieves these benefits. If you are undertaking new construction or retrofitting, consider these factors for efficient duct system design: location, installation and air distribution.
Choosing the right locations for ducts, air-supply registers and return grilles is paramount for efficient air distribution and preventing heat-energy loss. Follow these guidelines:
- Install ducts in the shortest route from the air handler to the living space.
- Avoid unconditioned areas wherever possible.
- Install at least one return grille on each level of the home. Small duct returns in each room with an air-supply register is preferable for optimal operation.
Consult a heating and cooling pro to evaluate which duct installation is best for your home, whether it’s trunk-and-branch or radial layout. Note these factors for correct installation:
- If ducts must be located in unconditioned areas, take extra care in sealing and insulating them.
- Avoid sharp angles, which hinder efficient air distribution.
- Ducts should taper as they extend away from the air handler. This maintains air pressure to distant air-supply registers.
- Building cavities are not substitutes for ducts. If you are utilizing building cavities, ducts should still be used inside.
- All duct joints, registers and grilles should be securely sealed to prevent separation and air loss.
- If needed, install adjustable volume dampers inside the ducts for even air distribution.
Your heating and cooling pro should calculate air supply/return for maintaining efficient air distribution and neutral air pressure. A faulty duct system contributes to air pressure variances, which promotes the transfer of indoor and outdoor air. This compromises all of your home-comfort systems, making them work harder for less efficiency.