Attic ventilation is essential in making any home more comfortable while lowering energy costs. Air-conditioners can run less and won’t have to work as hard.  Humid, stagnant air can be removed, drawing fresh dry air across the surfaces.  Your attic can be drier and cooler–the perfect tools to help fight potential moisture damage. Attics get hot because your roof takes the full brunt of the Sun's energy. As the Sun beats down on your roof, the shingles heat up–reaching temperatures up to 150°F.  This heat is transferred through the shingles, to the roof deck, to the lumber and rafters, and to anything else inside the attic. All of these materials will absorb and radiate the heat. - See more at: http://www.broan.com/products/product-line/attic-ventilation#sthash.l08…