It is not uncommon to see uninsulated heating ducts pushing air through unconditioned space. An unconditioned space is an area outside of the homes envelope, like a garage, basement or attic. When the furnace is off, these ducts become conduits for cold air into the house. And when the heat is on, much energy is lost. The example below shows a heating duct through a cold garage. Ouch!!

According to the US Department of Energy, in a typical house, 20 percent of the air that moves through the duct system is lost due to leaks, holes, poor connections or being poorly insulated.

The duct in the attic below, although tight only has a foil wrapped fiberglass insulation. When we were done with it, it was buried in a warm blanket of 14" of cellulose.

Tightly-sealed and well-insulated ducts keep you more comfortable and increase the energy efficiency of your home. Sealing also helps improve indoor air quality by reducing the risk of dust, moisture, pollen, pests, and noise from entering the ducts and circulating throughout your home.