How Many Attic Fans Are Needed

It doesn t matter if the ventilation openings are spread out as long as there is sufficient space for all the air to escape.

How many attic fans are needed.

Because what happens is attic fans are so strong that they actually reach down into the conditioned space of your house and they do that by using the wall cavities and where the outlets and pipes come through the walls as places where they draw air from the inside of your house it s that air conditioned air and it ll pull it right up into the attic and exhaust it outside. With square foot living space at a premium many homeowners turn to their attics for a little extra room. Vent fan location locate roof mounted fans on the back of the roof below the ridge but not so high as to be visible from the front of the house in the middle of the main part of the attic. So if your fan is rated at 1500 cfm you will need about two feet of totally open space in your attic.

If your roof is 1200 sq ft soffit floor space you will need 4 sq feet of roof ventilation. There should also be a 50 50 balance of attic venting and roof venting. Federal housing authority recommends a minimum of at least 1 square foot of attic ventilation for every 300 square feet of attic floor space evenly split between intake and exhaust. Use the calculator below to find out how many exhaust and intake vents you will need on your house.

Note that these two feet would not need to be one large opening. According to their requirements you should have 1 square foot of attic ventilation per 300 sq ft of attic floor space. Attic fans exhaust hot air from your attic to the outside. According to the home ventilating institute hvi powered attic ventilators need to move a minimum of 700 cubic feet per minute cfm for 1 000 sq.

Use only soffit vents as fresh air intakes for powered attic ventilators. Ok i would definitely not recommend an attic fan. When the attic becomes part of the home to be heated and cooled open wall gable vents and. The uniform building code requires that the amount of venting area in the attic be equal to 1 150 of the area of the floor and in most circumstances it allows a ratio of 1.

Ft of attic space for example 20 x 50 to be effective. A minimum of one square foot of inlet area for every 300 cfm of hvi certified fan capacity is required for proper fan operation. These fans are designed to remove excess heat from your attic which in theory is supposed to lessen the load on the air conditioning in your home. An attic fan is installed on the slanted side of your roof or on one of the gable sides of your attic.