Roof vents are designed to facilitate the movement and exchange of air within your attic and the exterior of your home. They can be broadly categorized into intake and exhaust vents, which respectively draw air into and move air out of your home. Understanding the variety of different vents and what they have to offer can help you decide what type of vents to install in your roof (for further assistance, contact a local roofing contractor) to meet your home's needs.
Intake vents are almost always installed in the eaves of your home. The two most common types of intake vents are drip edge vents and soffit vents.
Drip edge vents are installed at the very edge of your eaves, and provide a small vent that goes around the entirety of your house. However, homes that use a drip edge vents are not able to have a gutter system installed, which can be a problem in climates that receive a great deal of snow and rain.
Soffit vents are far more common, as they can be used with gutters, and are installed periodically within the soffits of your home. When installed, the interior location cannot be insulated so as to allow air to properly flow into your attic.
Exhaust vents move stale, hot air from the inside of your attic to the outside of your home, and are essential to keeping your home cool in the summer months. Exhaust vent can be further grouped into static, dynamic, and powered vents, all of which perform the same function in a similar way.
Static vents are installed near or on the peak of your roof. As air within your attic heats up, it will rise through the vent and into the outside of your home, allowing fresher, cooler air to move in through your intake vents and lowering the interior temperature. This passive method of ventilation is fairly slow, but will work constantly.
Dynamic vents work through the use of wind. The most common type of dynamic vent is the turbine vent, which will spin when the wind blows, sucking air up within your attic and outside. When the wind is blowing, dynamic vents will be able to ventilate your home much quicker than a static vent can, but they are much less effective during windless days.
Powered vents make use of electricity to use a fan to blow air out of your attic. These are the most effective type of roof vents, and when used in conjunction with an air conditioner, can effectively and quickly cool down your home. However, these are the most expensive type of roof vent and have long run costs in the form of higher energy bills associated with them, making them less than ideal for homeowners with a tight budget.