Which Materials Insulate Best & Why?

Silica Aerogel

• Silica aerogel is the lowest thermal conductivity material available. By not conducting thermal heat well, it essentially traps heat or cold within a house, not allowing it to escape. With the lowest bulk density of any porous solid, nano-sized pores stop heat from being transferred from one region of low temperature to another at high temperature, or vice versa. Nanogel is the most common brand of aerogel insulation.

Concrete

• Insulated concrete forms are used not only as permanent insulation, but also add to the structural form of a building. The forms are locked together without mortar. Concrete is poured in between them to form the wall or floor, often with rebar added to give more strength to the concrete. Concrete works because of it thermal insulation properties -- it stops the heat flow between two areas of differing temperatures. It also creates a soundproof area, acoustically insulating a house or room.

Spray Foam

• While fiberglass is the standard means of insulating a home, spray foam is quickly superseding it in the market. According to Ecotech, the foam insulates 30 percent to 50 percent more effectively than traditional materials. Created out of polyurethane, the foam can be a semi-permeable vapor barrier in order to reduce moisture, yet provides no conduction of heat or cold in and out of the home. It is also used as a sound barrier.

Radiant Barrier Foil

• While spray foam, concrete, and aerogel all insulate through reduction of convection and conduction, radiant barrier foil insulates though reduction of radiation. Insulation is generally associated with homes in colder regions, however, buildings in hot climates also need insulation from heat. An insulation that protects against radiant heat is the means of doing this. There is little transfer through a foil barrier by radiant heat as it reflects 95 percent of heat that hits it.