Duct Insulation During Summer Months

The Case for Insulating Duct Work:

Summer is approaching, and Comfenergy will soon be receiving calls for insulating ducts in a home.  There are two reasons we insulated ducts, and they differ by location of the ducts within the home.  Here is the business case for Insulating your Duct Work:

1)     Energy Conservation:  Often referred to as the Fifth Fuel source (behind Coal, Hydrocarbons, Nuclear and Renewables), many home owners are motivated to insulate their ducts in order to conserve energy.  A corollary to this is that improved comfort results from the effort to save energy. (see my blog about energy conservation ).  The ducts most impacted are those that reside outside of the building envelope.  In our area, this means “Ducts in the Attic”.  We sometimes find uninsulated metal duct work in unconditioned (read hot as heck) attics.  Think about the logic of this situation.  Machine makes cold air, and then pushes it through hot metal duct work on it’s way to the targeted room it is trying to cool.  By the time it gets there it is not that cool anymore.  Even when the ducts are insulated, they generally have (R6) insulation, a very low level of thermal resistance.  Encapsulating these ducts can more than double the insulation value and serve to air seal small gaps that allow air to escape from within the duct to the unconditioned attic space (wasted energy).  For a little more insight on this, watch this video clip from Dr. Energy Saver:


2)     Reduce the Probability of Condensation:  Ducts that are within a home (often times on the lowest level of the home) sometimes experience condensation issues during the hot humid days of our Mid-Atlantic summers.  This can be true even if the ducts are wrapped in fiberglass insulation.  This has become an issue for many homeowners in our area who have recently changed their HVAC system (the reasons why can be explained to you by a Comfenergy Consultant, but are beyond the scope of this article).  Encapsulating the duct work with spray foam serves the purpose of increasing the external temperature of the ducts to a level above the dew point of hot humid air that can leak into the effected area of the basement from the outdoor environment.  Fiberglass insulation systems often leave enough of an air gap between the cold steel and the warm moist air to create a condensation issue. Spray polyurethane insulation is essentially glued onto the surface of the ducts in a manner that eliminates all air gaps.

Insulating your ducts with spray foam is a great idea.  It conserves energy, improves comfort and reduces the probability of having condensation issues that can create mold in your home.

Call Comfenergy and we will help you determine if this solution will work in your home to accomplish your goals.