Attic Air Barrier

Some studies show that radiant barriers can reduce cooling costs 5 to 10 when used in a warm sunny climate.

Attic air barrier.

The reduced heat gain may even allow for a smaller air conditioning system. Whether using loose fill or batts put the vapor barrier closest to the warm side of your installation where hot moist air would get in facing the house s interior in cold climates beneath floor insulation and the attic s interior in hot climates on top of floor insulation. Radiant barriers are more effective in hot climates than in cool climates especially when cooling air ducts are located in the attic. Just because a failure in the air control layer air barrier shows up in the heat control layer insulation doesn t mean it s the fault of the insulation.

Exterior air barriers control infiltration of exterior air into the wall cavity and through the attic limit the ability of moist outdoor air to enter the wall cavity during the cooling season and prevent wind washing of wall insulation i e even though a house tests tight on the interior it could have a leaky exterior wall and top plate that cause big energy losses. A radiant barrier can lower heat transfer from attics to the building below keep the attic space cooler and lower cooling costs by up to 17 in warmer climates. Some regions don t require a vapor barrier.