To create a comfortable home, an efficient duct system is a must. Ducts—known collectively as the air distribution system—carry air from the central heater or air conditioner to each part of the home and back again. Up to 50 percent of the energy used to heat or cool air can be wasted if ducts are not sealed and insulated properly. That’s why the duct systems found in ENERGY STAR qualified homes are third-party tested for tightness and verified to be properly insulated.
BENEFITS OF EFFICIENT DUCT SYSTEMS
BUILDING EFFICIENT DUCT SYSTEMS
Techniques and practices that provide an efficient and effective duct system include:
SOURCE: ENERGY STAR
BENEFITS OF EFFICIENT DUCT SYSTEMS
- Improved Comfort: When ducts are properly sealed and insulated they deliver conditioned air more effectively to all rooms, helping to ensure a more constant temperature throughout the home.
- Lower Utility Bills: The average homeowner spends more than $600 on space heating and cooling each year. Tightly sealed and well insulated ducts found in ENERGY STAR qualified homes can reduce annual utility bills by $150 or more.
- Improved Indoor Air Quality. Leaky ducts in attics, crawl spaces, unfinished basements, and garages can allow dirt, dust, moisture, pollen, pests, and fumes to enter the home. Sealing these ducts helps improve indoor air quality.
- Lower Equipment Costs. When ducts are leaky, the heating and cooling system has to work harder to condition the home. Duct sealing, along with proper insulation, allows the installation of a smaller, less costly heating and cooling system.
BUILDING EFFICIENT DUCT SYSTEMS
Techniques and practices that provide an efficient and effective duct system include:
- Ducts in Conditioned Spaces. Ducts operate more efficiently in conditioned air at room temperature. They do not work as well in excessively hot or cold attics and crawl spaces.
- Sealed Ducts. EPA promotes the use of mastic and/or Underwriters Laboratory (UL) 181 approved tapes, such as metal-backed tape, to seal ducts. These materials more effectively seal leaks around duct joints and seams than standard “duct tape.”
- Insulated Ducts. Up to 25 percent of the energy used to heat and cool a home is typically lost through conduction between the duct surfaces and unconditioned spaces. To minimize this energy loss, EPA first recommends installing ducts in conditioned spaces. Where this is not possible, ducts should be insulated as recommended by the 2006 International Energy Conservation Code (IECC).
- Right-Sized Ducts. Ducts in ENERGY STAR qualified homes should be sized based on the Air Conditioning Contractors of America (ACCA) Manual J and Manual D calculations. This helps ensure that the ducts accommodate the air flow requirements of the heating and cooling system for efficient distribution of heated or cooled air.
SOURCE: ENERGY STAR
