Part Three: "Tight Construction and Ducts" in the Series "6 Ways a New Home will Cut Your Energy Bill"

Efficient Duct Systems

Optimize the Home’s Comfort Delivery System

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. In a typical house about

20 percent of the air that moves through the duct system is lost due to leaks, holes,

and poorly connected ducts. 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

• 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 $120 or more.

• Improved Indoor Air Quality.

Leaky ducts in attics, unfinished

basements, crawl spaces, 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.

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.

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.

connections can waste 20 percent or more of the air that you pay to heat and cool. 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 International Energy

Conservation Code (IECC).

Right-Sized Ducts.

Conditioning Contractors of America (ACCA) Manual J and Manual D calculations. This helps

to ensure that the ducts accommodate the air flow requirements of the heating and cooling

system for efficient distribution of heated or cooled air.

A BETTER FUTURE

ENERGY STAR is a voluntary partnership between the government and more than 9,000

organizations, including more than 3,500 of the nation’s home builders. Together with home

buyers and their families, we are working to achieve a common goal—protecting the

environment for future generations by changing to more energy-efficient practices and

products today.

ENERGY STAR is the government-backed symbol for energy efficiency. It identifies new

homes, buildings, and more than 50 types of products that are energy efficient and offer the

features, quality, and performance that today’s consumers expect. Products that can earn the

ENERGY STAR include windows, heating and cooling equipment, lighting, and appliances. To

learn more about ENERGY STAR, visit www.energystar.gov.

Ducts in ENERGY STAR qualified homes are sized based on the AirLeaky ducts and poorly sealedEPA promotes the use of masticDucts operate

Typical Places Where Ducts Leak