Vented attic roof designs have the advantage of a long proven historical track record.
Does attic needs ventilation.
Attic ventilation fans could be effective if your home has.
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.
Good ventilation allows the heat and moisture to escape.
This allows for a continuous flow of air through the space.
Intake vents located at the lowest part of the roof under the eaves allow cool.
What does attic ventilation do for my home.
Attic insulation that is less than r 19.
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.
Control of ice dams moisture accumulation and heat gain can be successfully addressed by both vented and unvented attic or roof design.
In the summer good attic ventilation reduces heat buildup.
Attic fan ventilation 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.
That said air resistance and interference such as vent grates reduces the area of true ventilation.
Does my home need attic ventilation fans.
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.
That cuts cooling costs and prolongs shingle life.
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.
Effective ventilation provides year round benefits creating a cooler attic in the summer and a drier attic in the winter.
How to determine whether you need better attic ventilation.
It may be starting to sound like attic ventilation fans aren t worth the hassle and could cause more problems than they solve.
How attic ventilation works.
However there are certain circumstances where they can prove useful.
Enter square footage calculate or enter the square footage of the attic or area to be vented.
Effective ventilation in an unfinished attic usually includes intake vents down low along the soffits and exhaust vents up high at the peak or roof ridge.
In the winter warm moist air seeps into the attic from the living space below.
However the designs need to be climate sensitive.
The choice of the venting approach is up to the designer.