Why Insulate Exhaust Ducts?

The principal reason that exhaust ducts are insulated during the construction of a home is to eliminate the risk of condensation. In high humidity regions or areas with great temperature extremes, the air can easily condense on the outer surface of the duct, causing water to drip and cause damages to the home. Builders and contractors can easily prevent condensation on ducting by using the correct insulation solution. Choosing the right insulation thickness, known as “R Value”, will help the air stay at the desired temperature, prevent air leaks and unwanted condensation.

Different types of exhaust duct insulation are recommended depending on whether the duct is located in a “conditioned” or “unconditioned” area of the home.

Conditioned Spaces

A “Conditioned” space is the area of the home in which we live. This area is heated and cooled for the purpose of comfort. Within conditioned spaces you may find floors and floor joists if adjacent to other conditioned spaces, for example the floor between a 1st and 2nd story of home, as well as interior walls and ceilings which are contained within the home’s interior envelope. Conditioned spaces in the home include bathroom, kitchen, bedroom. A minimum of R6 insulation value is recommended for these areas.

Unconditioned Space

An “Unconditioned” space is within the outer shell of a home; the are areas that are not affected by heating and cooling, but can be dramatically affected by outside elements such as summer heat and winter cold. Unconditioned spaces include the attic, crawl space, garage or exterior walls. A minimum of R8 insulation value is recommended for these areas.