Radiant barriers are installed in homes — usually in attics — primarily to reduce summer heat gain and reduce 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.
Ventilation is very important in an energy-efficient home. Air sealing techniques can reduce air leakage to the point that contaminants with known health effects such as formaldehyde, volatile organic compounds, and radon are sealed into the house. Ventilation also helps control moisture, which can lead to mold growth and structural damage.
Fiber glass, rock wool, and slag wool insulation systems are proven energy efficiency technologies which after the initial production, require no energy to save energy. Unlike other “energy-saving” products that merely claim to reduce the amount of energy they use, fiber glass, rock wool, and slag wool insulation’s major purpose is to save energy.