Installing a roof ventilation system on your home will keep it cool, help your roof last longer, and prevent damage from moisture. Depending on your home's climate, the lack of attic ventilation options can result in ice dams, cracking shingles, moist air, and high energy costs. According to the FHA, homeowners should have 1 square foot of attic exhaust for every 300 square feet of attic square and many shingle manufacturers are requiring some form of proper roof ventilation to meet warranties. Let's take a look at the types of roof vents and which one is best for you.
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Different types of roof ventilation
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Ridge vents are the most common type of exhaust vents for most residential roofing systems, which are installed on the top of the roof and run across the entire roofline. Located at the highest point of your home, ridge vents are able to dispense large amounts of hot attic air. While external baffles are not always required, they're highly recommended. Many manufacturers like CertainTeed make ridge vents designed with external baffles to help deflect wind, rain, and snow from infiltrating the vent.
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How ridge vents and static vents work
When ridge vents are combined with soffit vents, they allow consistent airflow underneath the roof deck. As warm air rises through the ridge vent and wind blows over the roof, it brings in cool air from the soffits below.
Box or static vents
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Static or box vents, also known as low-profile vents or louvers, are another popular vent choice. These vents are typically installed in groups on your roof, therefore offering more versatility. However, installation for box vents is a little more complicated, requiring holes in the roof sheathing to fit the vents. These types of vents work best for smaller spaces, open attics, and more complicated rooflines. Because they're not mechanical vents, box vents work well with soffits to move hot air out of the attic.
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Gable venting is another type of passive ventilation and is very common among gable roofs and colder climates. Gable vents are typically placed on opposite sides of the house and work together as an intake and exhaust vent. Gable vents work best with soffits. Unfortunately, ridge vents are a poor choice when it comes to gable venting. Gable and ridge vents are too close to each other to disperse air properly, causing mildew and moisture to build in the attic.
How gable vents work
Gable vents move cool air through one side of your home and hot air out the other.
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Turbines are powered by the wind, which turns the fan, brings the hot air in, and blows it out. The wind helps whip off excess rainwater and moisture. However, as wind turbines grow older, become rusty, and stop spinning, they're prone to leakage. While turbines can dispel a large amount of humid air, they can also pull cool air from air conditioning units. Turbines are typically seen more on commercial buildings and less on residential homes due to their conspicuous appearance.
How turbines work
As the turbine turns, it pulls hot air out of the attic, keeping it cool in warmer months.
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Power vents use electricity or solar power to remove hot air through intake vents under the eaves and disperse it through the fans. These attic ventilation systems usually feature two different speeds or are connected to a thermostat or humidistat, so you'll be able to control their efficiency and temperature. Though power vents are efficient in removing hot air from your attic space, they can drive up your energy bill.
While installing proper attic ventilation is important for homeowners in all types of climates, some types of vents work more efficiently in different seasons.
Fall and winter
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In the winter, it's important to keep your vents open and operable to prevent any type of moisture buildup or ice dams. As long as you have proper attic insulation, it's perfectly fine to have a cold attic, as long as you keep your vents clean and free of any ice or snow. Combined with soffits, gable vents tend to work well in colder months, just remember not to cover your vents with insulation.
Spring and summer
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In warmer months, it's important to disperse as much hot air as possible to prevent moisture. Having some type of combination of ridge vents, wind turbines, or power vents and soffits all make for a balanced ventilation system. Having roof ventilation during the summer is an energy-efficient way of bringing in fresh air and cutting down the use of an air conditioner.
Why roof ventilation is important
Roof vents are an essential part of your home, lowering energy costs, preventing damage, and extending the life of your roof. Passive, non-mechanical ventilation systems like ridge vents, static vents, gable vents, and turbines all work together with soffits to bring in hot air and disperse it, creating a more temperate attic floor. While installing ventilation can be expensive and prone to leaks if not maintained, choosing the right type of ventilation system is an important part of any new roof or living space.