Do Attic Vents Help Cool House

A powered attic ventilator has a different purpose.

Do attic vents help cool house.

Cool air in hot air out attic ventilation works on the principle that heated air naturally rises primarily utilizing two types of vents. Poor insulation is usually the culprit although if you enter the attic on sunny winter day your attic space can be warmed by the sun more than your furnace. Unless your roofing system has insulation on the roofing deck and is designed without ventilation your furnace should not be heating your attic. In fact there is good data in the comments that it does cool the house.

The point is that in some cases the cooling could be inefficient or even dangerous if drawing conditioned air or creating backdraft or humidity problems. Having a properly vented attic is the best way to keep attic cool because it allows the hot air to escape during the summer. Vapor barriers in the attic keep moisture rising from your living space away from the insulation. It is designed to lower the temperature of an attic by exhausting air from the attic and replacing attic air with outdoor air.

This prevents hot air from seeping into your home and driving up the temperature in the living space which reduces the load on your air conditioner. However if your attic has blocked soffit vents and is not well sealed from the rest of the house attic fans will suck cool conditioned air up out of the house and into the attic. Vents do provide some passive cooling but not enough to truly reduce your indoor temperatures. What that tells me is that cooling down the attic actually will cool the house it s just important to do it with.

When an attic fan is operating during the hottest summer days the temperature in your attic can drop by as much as 50 degrees. They are needed because damp insulation loses much of its value. Unlike a ventilation fan a whole house fan an attic mounted fan that exhausts air from a home at night is designed to cool a house that is to lower the indoor temperature. Cool regardless of the attic temperature.

Attic fans are intended to cool hot attics by drawing in cooler outside air from attic vents soffit and gable and pushing hot air to the outside. Vapor barriers can take the form of plastic. Attic ventilation fans help cool air your attic by pushing out the stifling hot air from inside the attic and bringing in cool air from outside.