Insulation and Green Building Products

A more traditional insulation choice, fiberglass insulation is a cost-effective, energy-saving product that is made from sand and recycled glass.

It has helped make the insulation industry more efficient by reducing energy loss and decreasing production costs.

By avoiding the added energy needed to heat and cool buildings, fiberglass insulation continues to be a benefit to the environment by helping to reduce pollution emissions.

While the energy savings from fiber glass insulation are significant, so are the environmental benefits.

By making buildings more energy efficient, fiberglass insulation helps reduce the amount of fossil fuel combustion needed to heat and cool homes, businesses, and factories. That, in turn, decreases the amount of carbon dioxide emitted into the atmosphere.

Understanding R Value

The R-value is a measure of insulation's heat loss retardation under specified test conditions. The primary mode of heat transfer impeded by insulation is convection but unavoidably it also impedes heat loss by all three heat transfer modes: conduction, convection, and radiation.

The main means of heat loss across an uninsulated air-filled space is natural convection, which occurs because of changes in air density with temperature. Insulation greatly retards natural convection. Most insulations trap air so that significant convective heat loss is eliminated leaving only conduction and radiation transfer.

The chief role of such insulation is to make the thermal conductivity of the insulation that of trapped, stagnant air. However this cannot be realized fully because the glass wool or foam is needed to prevent convection and increases the heat conduction compared to still air.

Radiative heat transfer is minimized by having many surfaces interrupting a "clear view" between the inner and outer surfaces of the insulation. Such multiple surfaces are abundant in batting and porous foam. Radiation is also minimized by low emissivity (highly reflective) surfaces.

Lower thermal conductivity and, therefore, high R-values can be achieved by replacing air with argon when practical such as between sealed double-glazed windows and within special closed-pore foam insulation.