Attic ventilation: Ridge vent or turbine
Proper ventilation plays an important role in prolonging the life of your roof. During winter, attic ventilation is needed to prevent ice dams from forming, and during the hot summer months, ventilation helps to remove hot air which reduces mold growth and protects the shingles from excessive heat.
Ridge vents and turbines
A turbine is installed directly on the top of a roof and uses wind power to suck hot and humid air out of the attic. A turbine has a series of vanes that spin as wind passes through them.
A ridge vent runs across the top of the roof's peak. Unlike turbines, this venting style does not have any moving parts. A ridge vent is similar to a screen and allows heat to escape up and out of the attic.
Roof turbines are usually less expensive to install because they only require the removal of a small section of shingles and an appropriately sized hole to be drill through the roof. Flashing and sealant is used to prevent water from seeping in around the opening.
Ridge vent systems normally run the full length of the roof. For this system to be installed on an existing roof, the entire peak must be cut away, which can make the installation more expensive than installing a turbine.
Due to their moving vanes, turbines provide more air movement than ridge vents. However, if you're in an area without a great deal of wind, a turbine may not work well.
A ridge vent is a passive system and offers less air movement, and in moderate climates this style tends to be sufficient. In more extreme climates, one or more turbines will provide better circulation. For optimal performance, ridge vents require soffit venting to bring air up and out the top of the roof.
Regardless of the type of attic ventilation you choose, it's important that's it's installed correctly by a licensed roofing contractor. A roofing contractor can also help you determine the best type of attic ventilation for your home. For more information, visit the Angie's List Guide to the Anatomy of a Roof.