Whether you’re undertaking new construction or a duct retrofit with a heating/cooling system upgrade, proper duct design provides efficient air pressure throughout the living spaces to ensure maximum home comfort and energy savings.

Air pressure and free airflow

Poor duct design results in air pressure variances inside a home. This can contribute to air infiltration through the home’s envelope, and create additional work for the heating and cooling systems. Air infiltration may also occur through leaks in poorly designed or unkempt duct systems.

Your HVAC professional should adhere to the following elements of proper duct design for best results in your Northwest Arkansas home:

  • Sizing: Your HVAC pro should utilize ACCA’s (Air Conditioning Contractors of America) guidelines for calculating your home’s heating and cooling loads (Manual J), sizing the heating/cooling system if applicable (Manual S), and sizing and designing the duct system (Manual D).
  • Layout: Popular duct-design configurations include trunk-and-branch and radial, or a custom modification to efficiently match the layout of the home. Whichever configuration your HVAC pro determines is best, duct runs should be limited to conditioned spaces (inside the insulation barrier). Return grilles should be located in each area with a supply outlet. If this isn’t practical or in the budget, transfer grilles in doors and walls must be implemented to permit free air circulation.
  • Sealing: Duct seams should be sealed with sheet-metal screws, mastic sealant and butyl tape.
  • Testing: To ensure a leak-free duct system, a blower door test should be performed to reveal any air leaks. Once the duct system has aced the blower door test, any ducts that were installed outside the insulation barrier must be insulated.

The energy efficiency of your home’s envelope contributes to proper air pressure, too. If you are retrofitting your existing duct system, consider asking your HVAC pro for a home energy evaluation to pinpoint areas in your home’s shell that need attention with regard to air leaks and boosting insulation.

For more information about proper duct design, please contact us at Paschal Heat, Air, Geothermal & Generators today. We’ve provided top-quality service and installation for homeowners in Northwest Arkansas for more than 40 years.

Our goal is to help educate our customers in Northwest Arkansas about energy and home comfort issues (specific to HVAC systems).  For more information about  Proper Duct Design and other HVAC topics, download our free Home Comfort Resource guide.

Image courtesy of Shutterstock