If I want to save energy, why not use passive solutions like ridge or soffit vents, these don use electricity and they are virtually invisible on the roof?
During the summer, as the sun radiates heat onto your roof, your roof’s shingles or tile become very hot, well above 150 degrees F. This heat is transferred through the roof and in turn heats the air inside the attic. Ridge vents or soffit ventilation is sometimes referred to as convection ventilation, the theory being simply “hot air rises” and will vent on its own. Unfortunately this theory is somewhat flawed because heat also expands and radiates. The roof holds the heat, the attic holds the heat, and everything in your attic holds the heat. As your roof begins to broil, the air in your attic begins to expand, in every direction not just up. There is no question the vents at the ridge of your home will exhaust air, but only as it is warmed to the point of expansion. In short, the convection-ventilation process actually requires heat retention to begin in order to maintain this inadequate ventilation process. Your roof will never be cooler than the heat load point required for convec
