Insulating materials reduce the heat flow in a home, which allows the air a cooling or heating system produces to stay inside, and protect a home from external temperatures. Insulating materials are given R-values based on their insulating effectiveness; the higher the R-value, the more effective the material is.
Most insulating material is made of fiberglass, which is relatively inexpensive, easy to install and is nonflammable and moisture resistant. Mineral wool is another popular insulating material. It is composed of approximately 75 percent recycled material and is less irritating than fiberglass-based insulation. Though comparable to fiberglass, mineral wool is generally more expensive and more difficult to find.