Insulation materials, in Wallace, are the materials or combinations of materials which inhibit the flow of heat energy. Insulation materials may be broadly categorized as: organic and inorganic materials. Polystyrene, polyurethane, phenolic foam, polyethylene foam, etc, fall under the organic foam category. Mineral wool, calcium silicate, cellular glass, micro-porous silica, magnesia, ceramic fiber, vermiculite and perlite are the inorganic insulation materials. These materials are used in varying combinations to obtain desired thermal comfort with less energy consumption.
Insulation materials can also be categorized into structural & non-structural materials, based on their form. Structural forms include insulating concrete forms, structured panels, and straw bales; while, non-structural forms include batts, blankets, loose-fill, spray foam, and panels. According to their mode of action, they may be of three types- conductive, convective & radiating insulation materials.