Technical Corner – Tips for the Balance System for Attic Ventilation® by Air Vent, Inc.

A short explanation of attic venting by the experts, Air Vent, Inc., for proper attic venting and its importance. Proper roof venting is critical all over Hampton Roads from Yorktown to Virginia Beach to keep your shingles from baking in the harsh summer sun and the heat produced in our attics, as well as, preventing condensation and the mold that goes along with it in the winter time.


 Tip 1. Don’t Short-Circuit Your Ventilation System.
Never install more than one type of exhaust system. The stronger exhaust vent will pull from the other causing one vent to function as an intake vent and the other as an exhaust vent, short-circuiting the ventilation system. This leaves a large area of the attic unventilated and increase potential weather infiltration problems.

Tip 2. Balance Intake and Exhaust.  Research has shown that the best way to ventilate an attic is with a year-around system that provides continuous airflow along the entire underside of the roof sheathing. Achieving this desired airflow requires a balanced system of Intake Ventilation low at the roof’s edge or in the soffit/eaves and Exhaust Ventilation at the ridge. A balanced system can help fight excess heat buildup in the summer, moisture buildup in the winter and help defend against ice dams before they become serious problems.



Tip 3. Achieving The Balanced System. To achieve The Balanced System is to get the most exhaust out of the attic. The intake net free area should be equal to or exceed the exhaust net free area. According to building codes a balanced ventilation system means at least 50% of the required vent area must be intake and 50% exhaust. However, many ventilation engineers recommend installing additional intake to maximize airflow.


Two important principles to remember: Ventilation is a system of intake and exhaust that allows air to follow the path of least resistance, and a balanced attic ventilation system provides an equal amount of intake and exhaust for optimum airflow through the attic.

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