Radiant barriers are installed in homes — most commonly in attics — to reduce summer heat gain and winter heat loss, which helps lower heating and cooling costs. The barriers consist of a highly reflective material that reflects radiant heat rather than absorbing it. They don't, however, reduce heat conduction like thermal insulation materials.
Plastic fiber insulation material is primarily made from recycled plastic milk bottles (polyethylene terephthalate or PET). The fibers are then formed into batt insulation similar to high-density fiberglass.
Blanket insulation — the most common and widely available type of insulation — comes in the form of batts or rolls. It consists of flexible fibers, most commonly fiberglass. You also can find batts and rolls made from mineral (rock and slag) wool, plastic fibers, and natural fibers, such as cotton and sheep's wool.
This topic includes information related to blanket insulation installed during construction. Blanket insulation is commonly installed along crawl space foundation walls, between studs, joists and rafters. Blanket insulation materials include; fiberglass, mineral wool, plastic fibers and natural fibers.