Sizing Attic Ventalation Fans And Intake Louvers

They re commonly used to reduce moisture and remove smoke and odors in restaurants residences shop and production floors and commercial buildings.

Sizing attic ventalation fans and intake louvers. This attic ventilation calculator computes the size and number of solar powered attic fans to achieve the proper ventilation for your attic. Intake vents located at the lowest part of the roof under the eaves allow cool. For balanced ventilation an equal amount of intake vent area net free area should also be installed. Exhaust fans mount through a cutout in a roof or wall.

Shed vent door vent built in screen gable vents louvers white gable vents louvers 12x16 return air grille 24 in. It s also important to have plenty of soffit or gable vents for the fan to draw air into the attic. Fan related products 19 25 in. Exhaust fans force out stale indoor air so it can be replaced by fresh outdoor air.

Proper attic ventilation consists of a balance between air intake at your eaves soffits or fascias and air exhaust at or near your roof ridge. Federal housing authority recommends a minimum of at least 1 square foot of attic ventilation evenly split between intake and exhaust for every 300 square feet of attic floor space. Use avp s roof vent calculator to determine the number and size of exhaust vents you will need. To find out if you have enough vent space divide the cubic feet of air per minute that the fan is rated for by 300 to come up with the minimum number of square feet of intake vent space needed for that size fan.

In general there are five types or categories of exhaust vents. Attic ventilation works on the principle that heated air naturally rises primarily utilizing two types of vents. The ravc recommends never mixing two types of exhaust vents on the same roof above a common attic because it could short circuit the attic ventilation system.