Attic Ventilation Too Much Intake

This gives me an intake of over 6139 sq inches.

Attic ventilation too much intake.

So how much intake ventilation do i need. I know the question will come up why am i using so much vented soffit. If there is more intake ventilation than the attic s square footage requires it s not problematic because any excess intake converts to exhaust on the leeward side of the house. 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.

If there is no vapor barrier double it to one square foot of nfa for every 150 square feet of attic floor space half for intake half for exhaust. In this post we cover the intake ventilation. Do not use mechanical means electric attic fans. Roof ventilation keeps the air moving and stops mold from growing but too much ventilation can be just as bad as having none.

It s possible to have too much exhaust ventilation but you cannot have too much intake ventilation. This value is split evenly between intake and exhaust ventilation. As a certified licensed home inspector it is not correct to say too much ventilation is bad for an attic unless rain moisture is getting in. The ideal amount of attic ventilation is one square foot of vent space for every 150 square feet of attic area.

If i put ridge vent on 100 of all ridges i end up with 2736 sq in of exhaust. If the attic ventilation system cannot be balanced 50 intake 50 exhaust it s better to have more intake than exhaust because it s been our experience most houses lack proper intake. I know intake must always exceed exhaust to avoid negative pressure possibilities but is this plan too far out of balance to the intake side. All it takes to grow mold in your attic is stagnant humid air.

And when you put too many products on your roof that s improper ventilation. What happens is people put too many products on their roof. Tips for assessing your needs. 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.

Attic length x attic width 150 total vent space or net free area nfa. 2 focusing only on heat buildup. If a roofing contractor is going to be out of balance with the attic ventilation system it s better to have too much intake than too much exhaust because the excess intake converts to exhaust on the leeward side of the house. Venting a homes attic is a very important best building practices will say 50 at the ridge and 50 at the soffits unobstructed.