Vent Attic Or Not

Without exception you should talk to a professional to determine what your home requires.

Vent attic or not.

That said air resistance and interference such as vent grates reduces the area of true ventilation. Roofs need a driving force to move air in and out and intake and exhaust vent openings large enough to facilitate this movement. Attic fans can be useful if you don t have proper passive ventilation. If you ve accidentally painted over air vents insulated soffit venting or covered up an exhaust port then an attic fan can be helpful to move air around.

However the opposite is true if the attic floor is air sealed and insulated. As such it would seem venting the attic would increase the potential for condensation. Attic ventilation works on the principle that heated air naturally rises primarily utilizing two types of vents. Intake vents located at the lowest part of the roof under the eaves allow cool.

The other option of course is a vented attic which requires an equal balance of intake and exhaust vents. Should you vent a metal roof. If water or air ducts run through your attic space they are less likely to be affected by extreme temperatures and this can save you money on utility costs. However most varieties require electricity to operate need proper upkeep and can be noisy.

Generally speaking you need a ratio of 1 300 where for every 300 square feet of ceiling space you need 1 square foot of attic ventilation. In many cases for existing homes this is the easier way to go. You ll need to vent your attic because water vapor showers laundry people will still migrate through the ceiling into the attic space. As the warm air escapes through vents high on the roof cooler air enters the lower vents.

Even when outside air is hot and humid if the attic space is air sealed from the interior it is much hotter than outside air. In an attic the primary driving force is the buoyancy of warm air rising in the vault of the roof.