Air ducts have no moving parts, don’t cool or heat airflow and have no SEER and HSPF ratings to display on an EnergyGuide label. Yet, poorly designed ductwork costs the average homeowner up to 30 percent extra cooling and heating dollars. So, a substantial portion of your energy budget depends on ductwork efficiency, which depends on good design.
Metal Ducts or Fiberglass?
The type of duct material you choose may depend on cost, preference or space conformity. Sheet metal and fiberglass flex ducts are the most popular materials, and both have their pros and cons. Sheet metal offers less airflow resistance, but it can pop and rattle under stress. Fiberglass flex ducts offer smoother turns, and they are pre-insulated for installation in unconditioned spaces. Work with your HVAC contractor to select the best duct materials for your purposes.
Ducts are generally installed in the attic or basement to save space in the living areas. However, ducts are vulnerable to energy losses. So, locating ducts within the insulation barrier, such as inside sealed chases and raised floors, offers energy-saving advantages. Building cavities in walls and between basement and attic joists are not to be used as airways. This was common in older homes, but it’s not acceptable in today’s efficiency standards.
Correctly sizing ductwork is important for even temperatures throughout the home and balanced supply and return airflow. Ducts should be sized using specifications of Manual D from the Air Conditioning Contractors of America (ACCA). Ducts that are too small or too large can damage HVAC equipment, force air infiltration and increase energy bills.
Leaky and loose ducts rattle and clamor, and simply waste your energy dollars. Good duct sealing entails approved materials and testing. Mastic paste or an aerosol sealant seals small holes and gaps at joints. Joints should also be wrapped with metal-backed tape for a secure connection.
For more information about ductwork efficiency, check out Weather Makers ductwork solutions or call 757-263-4869 to make an appointment.