Can i put pink insulation inside air ducts to close them off?
Both of the above answers are true! Don’t use pink insulation to close that off! Get foam board instead! If you are trying to close of heat vents, they actually make magnetic covers for this purpose. My furnace people and gas company tell me it is counter productive to close heat vents off though because the furnace works harder to get the air through the vents. Thus, no money saved. If you are talking about under the house, use the foam board. At my house it looks like a foam cooler side and it is just cut to fit and pushed into the vent space. Works just fine. In either case, I would not use the pink stuff becuse of the fiberglass.
