Attic Ventilation Theory

In mixed climates ventilation serves either role depending on the season.

Attic ventilation theory.

Ice dams form when a home s escaping heat warms the roof sheathing and melts the underside of the snow layer on the roof. More attic ventilation is good. A powered attic ventilator or attic fan is a ventilation fan which regulates the heat level of a building s attic by exhausting hot air. Several purposes of an attic ventilation system are to provide added comfort to help protect against damage to materials and structure and to help reduce energy consumption during all four seasons of the year.

Insufficient ventilation can lead to moisture problems during the winter and decreased energy efficiency during the summer but too much ventilation can be just as bad if not worse. This air passes through the attic space where it displaces warm moisture laden air which in turn exits the attic via vents at or near the top of the space being vented. Heat in the attic can roast shingles from below causing them to wear prematurely. Here are some of the myths and the facts you need to know about attic ventilation.

Intake vents located at the lowest part of the roof under the eaves allow cool. An attic fan can be gable mounted or roof mounted. Having attic ventilation doesn t ensure the moisture gets ventilated away before it condenses on your expensive roof and wall surfaces. A thermostat is used to automatically turn the fan off and on while sometimes a manual switch is used.

Another important element of attic ventilation is protection for the roof s shingle. While there are different product options available the process is typically done with a source of intake air fresh air normally drawn from the soffit or near the eaves and a source of exhaust typically near or at the roof s peak. In simplest terms attic ventilation is a process of creating air movement and circulation in the attic space. Just like properly sizing your furnace and air conditioning unit you want precisely the right amount of attic ventilation for your home.

It s believed that good ventilation in the attic will help prolong the life of shingles by reducing heat which maintains the shingles quality and durability. Attic ventilation works on the principle that heated air naturally rises primarily utilizing two types of vents. The intent of roof venting varies depending on climate but it is the same if you re venting the entire attic or if you re venting only the roof deck. In a balanced ventilation configuration ambient outside air enters into the attic space via soffit or eave vents.