Attic Ventilation Theory

In simplest terms attic ventilation is a process of creating air movement and circulation in the attic space.

Attic ventilation theory.

Attic ventilation works on the principle that heated air naturally rises primarily utilizing two types of vents. 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. An attic fan can be gable mounted or roof mounted. 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 mixed climates ventilation serves either role depending on the season. 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. 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. Heat in the attic can roast shingles from below causing them to wear prematurely.

More attic ventilation is good. Having attic ventilation doesn t ensure the moisture gets ventilated away before it condenses on your expensive roof and wall surfaces. Intake vents located at the lowest part of the roof under the eaves allow cool. 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.

The problem with this design is it is wishful thinking. Ice dams form when a home s escaping heat warms the roof sheathing and melts the underside of the snow layer on the roof. 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. Here are some of the myths and the facts you need to know about attic ventilation.

In a hot climate the primary purpose of ventilation is to expel solar heated hot air from the attic or roof to reduce the building s cooling load and to relieve the strain on air conditioning systems. A thermostat is used to automatically turn the fan off and on while sometimes a manual switch is used. The theory behind attic ventilation is to give that moisture a place to escape before it causes mold mildew rot or other problems. Another important element of attic ventilation is protection for the roof s shingle.