Insulation On An HVAC Duct Doesn't Just Conserve Energy!
I was in the attic of a Town House a while ago and for some reason the insulation covering the HVAC duct had lost its outer covering. Without that covering, the insulation was falling off and the duct was exposed to the heat and cold of the attic. First, let's just say that any HVAC duct passing through an "unconditioned space" should be insulated. Imagine how hard heating and cooling systems have to work when they are trying to pass hot air through a cold attic in the winter, or cold air through a hot attic in the summer. This wastes energy and makes the appliance work harder to do the job, thus shortening the appliance's life. There's an added reason you want to have insulation around your HVAC ducts in the summer though. Condensation! The air passing through the inside of the duct is anywhere from 45-55 degrees Fahrenheit. Much like a glass of ice tea on the counter-top during the summer, the hot/humid air in the attic hits the outside of the chilly duct resulting in condensation that can drip down and cause damage to the insulation and sheetrock below.


