By Tony Carrick | Updated Dec 22, 2020 1:29 PM

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Mold and mildew growing and shingles peeling away from the roof: These issues are caused by a poorly ventilated attic. Without a roof vent, attics can reach upward of 130 degrees Fahrenheit, which creates a breeding ground for mold and mildew. Moreover, the shingles could even peel away from the roof.

A roof vent solves these issues by creating a place for hot and humid air to escape. Roof vents come in many shapes and sizes. Electric, solar, and wind-powered vents use powerful fans and turbines that push warm air out of the attic space while pulling in cooler air through vents around the roof’s soffits. Static roof vents allow air to escape via vents that run along the entire roof peak or from small vent boxes.

To bring down the temperature in your attic, keep reading to learn about the different types of roof vents and the features you should consider when shopping for the best roof vents that can stand the test of time.

When determining the best roof vent for your home, you’ll find many types are available. They come in two main models: intake and exhaust, both of which are required to properly ventilate a roof.

Intake vents allow cool air to enter the attic and help push out the hot air, which freshens the space and decreases air temperature. You can place intake vents on the roof in one or more different areas.

Hot air in the home rises, eventually collecting in the attic. Exhaust vents allow the hot air to escape, preventing the buildup of heat. Unlike a dryer vent that vents through a wall, most exhaust vents exit through the roof.

Consider various factors when shopping for a roof vent, including the square footage the vent is rated to handle, the difficulty of installation, and the shape of the roof.

The square footage of the attic space determines the amount of venting needed to adequately remove humid hot air from a room. The U.S. Federal Housing Authority recommends at least 1 square foot of attic ventilation for every 300 square feet of attic floor space, with half of the ventilation at the lower portion of the attic—intake vents—and half at the upper portion—outtake vents. This is commonly known as the “1/300 rule.”

The features and shape of the home or shed’s roof largely determine the type of vent suitable for ventilating the attic space. A home with large soffits that run the length of the roof is best served by a combination of soffit vents and ridge vents. A house with a hip roof and no soffits may require drip edge vents and hip vents or box vents, while gable vents are probably suitable for a home with large gables. Assess the roof style when determining the type of vents that will work with the house.

Since vents must endure bad weather, they are made of durable galvanized aluminum or vinyl. They also come in various colors and finishes. Vents are not an attractive architectural feature on the home, so manufacturers try to hide them. Ridge vents are covered by shingles that match the rest of the roof. More conspicuous wind turbines, box vents, and electric fan vents come in different colors to blend with the roof shingles.

When determining which roof vent to use, consider the climate. While most vents can handle heavy rain and snow, hurricanes can wreak havoc on roof vents. Soffit vents and gable vents present opportunities for rain to be blown up and in to the attic. High winds can cause turbine vents to spin at speeds beyond their capacity, damaging them. Hurricane-force winds can peel ridge vents from the roof peak, exposing large gaps that rain can enter.

If you live in an area that often receives high winds or hurricanes, shop for roof vents designed to endure high winds. A low-profile box vent that’s not susceptible to high winds may make more sense than a wind turbine. Some ridge vents feature baffles that allow them to endure wind speeds of 110 mph or more.

Installation is another consideration when determining which vent to buy. Most external vents can be retrofitted onto an existing home. Box vent and wind turbine installation is a manageable job for most DIYers. Installing a ridge vent on an existing home can be a little more challenging because it involves removing the existing shingle caps and cutting a gap along the entire peak of the roof with a circular saw, which is a job best left to the pros, considering the danger of using power tools at a high elevation.

Intake vents, such as drip edge vents and fascia vents, are much more challenging to retrofit because of their location under the shingles along the lower lip of the roof. Installing these types of vents typically requires the removal of all of the shingles along the lower edge. Adding a drip edge vent or an over fascia vent is best completed during a new roof installation. Soffit vents can be added to a wood soffit fairly quickly by cutting holes in the soffit.

This list includes some of the top vents for cooling an attic space based on the type of roof. They feature durable construction that can withstand bad weather and efficient designs for handling large areas.

Once eschewed for the sleeker and more powerful electric fan vents, wind turbines have been making a comeback in recent years thanks to their green electricity-free design. The Whirlybird fan from Lomanco uses wind power to rotate its turbine to flush the attic of damaging heat and humidity. One unit can ventilate about 770 square feet of attic space.

The turbine’s 21 airfoils create enough surface area to rotate the turbine with a minimum 5 mph wind while also offering enough coverage to deflect rain from the hole. A pitch gauge included with the vent allows the turbine to easily set on the roof pitch, making installation relatively easy.

Easy installation, an affordable price, and a design that doesn’t require wiring make this Broan-NuTone Roof Vent Kit a good option for improving attic ventilation. This kit includes a low-profile external vent that won’t turn the roof into an eyesore. A back-draft damper ensures that warm air exits and does not enter the roof space, while a screen prevents birds and other critters from breaching the home via the vent opening.

This model fits into a 5-inch diameter hole. Wide flashing on the sides of the vent allows it to attach to the roof securely while also allowing overlap with shingles to prevent water from leaking between the roof and the vent. A durable black powder coat finish prevents the vent from rusting.

With easy installation and a low-profile design, the Cobra ridge vent from GAF is an option for adding ventilation to an attic space or shed. This vent comes in 48-inch-long sections that can be linked together to handle the square footage of virtually any attic. Three Cobra ridge vents are enough to cover a 1,600-square-foot attic when paired with the appropriate intake vents. At more than 13 inches wide, each strip adequately covers the roof’s peak, allowing for hot air to escape without allowing leaks.

This ridge cap works with standard 12-inch shingles. A tear-away design enables you to shorten the length of each ridge cap in 3-inch increments to prevent multiple climbs up and down a ladder to make cuts. With a durable design, this ridge cap can withstand winds up to 110 mph. Three-inch ring shank nails come with the kit for installation.

No required wiring and energy-saving solar power make this Solar Powered Roof Mount Exhaust Fan from Master Flow an excellent option for DIYers. It features a 15-watt fan with a brushless motor capable of producing airflow of up to 500 cubic feet per minute (CFM). The fan is rated to handle about 800 square feet of attic floor space.

The attached solar panel features swivel and tilt abilities up to 45 degrees to position it for optimal sun exposure. It works best with roof slopes ranging from 3:12 to 12:12 to allow for adequate drainage around the vent. An internal screen keeps small animals from entering the home through the vent. This model does not include a battery backup, so it runs only on solar power.

This model from Master Flow blows a lot of hot air. This 1,000 CFM Galvanized Steel Electric Fan can pump out enough hot and humid air to keep attics of up to 1,600 square feet cool. It’s an electric vent; however, this fan keeps energy costs down via its thermostat, which turns on the fan only when the heat in the attic reaches a certain temperature. Sturdy galvanized steel construction ensures the fan will hold up to harsh weather.

A large flange provides coverage away from the hole opening, preventing leaks from forming around the unit, while an internal screen keeps out the critters. With four color options—silver, black, light brown, and dark brown—this roof vent complements various shingle styles.

This beast, designed to fit over large gable vents, uses large 15-inch fan blades to produce a whopping 1,600 CFM. That’s enough air movement to ventilate gabled attics up to 2,400 square feet. The fan does not require a hole in the roof; instead, it attaches to the attic’s gabled end and blows air out through a louver vent.

An adjustable thermostat lets the homeowner set the fan to come on between a broad temperature range of 50 and 120 degrees, helping to keep down power costs. It features durable galvanized steel construction, and it must be hardwired into the home’s electrical grid.

A low-sloped roof on a home or large shed doesn’t provide much space for airflow. This turbine fan requires just 95 square inches of open space to promote adequate airflow for it to function. That’s a lot less than the 500 square inches or more of free space an electric fan requires to operate. While this fan may not move as much air, it can still provide adequate ventilation for an attic with up to 300 square feet of floor space. This model will work with roof slopes as low as 3/12. A large flange provides enough coverage around the turbine to prevent water from leaking into the attic.

The unit runs entirely off of outdoor air movement, making installation relatively easy. This sturdy fan features aluminum construction and four different color options, including white, tan, brown, and black, to match the home or shed’s shingles.

Take advantage of the multiple roof peaks created by a hip roof with a vent system that runs the length of those ridgelines. This ridge vent features air slots that allow warm air to escape the attic area. When combined with an air intake system, such as a drip edge vent, these ridge vents allow hot air to flow out. Running this system along the roof peaks can help provide maximum ventilation for the attic. An external baffle prevents air from flowing into the vent.

This vent features plastic ribbing that allows it to flex to fit roof pitches ranging from 3/12 to 16/12 without affecting its internal airflow. Its 14-inch width covers the vent with standard cap shingles that match the roof to create a finished look.

If you’re still wondering about the type of roof vent that’s best for your home, then read on for some of the most commonly asked questions about these vents.

A poorly ventilated roof can cause heat to build up to 150 degrees Fahrenheit or higher in hot weather, causing condensation to form, resulting in mold and mildew growth. This extreme heat also can cause the shingles to pull away from the roof, potentially leading to leaks.

Calculate the amount of ventilation your attic needs by measuring its square footage. You need a vent that provides 1 square foot of ventilation for every 300 square feet of attic space. Check the vent’s square footage rating to determine how large or how many vents you need to adequately ventilate your attic.

Once you’ve calculated the amount of ventilation you need, you can determine how many vents it needs to meet that demand. If, for example, you’re using a box vent that can ventilate up to 300 square feet and you have a 1,200-square-foot attic, you need to install two vents to provide 600 square feet of ventilation along with large enough intake vents to handle the other 600 square feet.

Begin by identifying the location in the attic to install the vent. Drill a hole through the roof, leaving the drill bit in the hole to make it easy to find when you head to the roof. Once on the roof, measure and draw the opening for the vent (the size is indicated in its instructions) using the hole you drilled as a guide. Use a reciprocating saw or jigsaw to cut through the shingles and roof sheathing. Loosen the shingles around the hole. Apply caulk around the vent’s flange. Install the vent by sliding the flange under the surrounding shingles on the top and sides, leaving the downward side over the shingles. Use the prescribed number of nails to attach the vent and secure any loose shingles.

Roof vents are designed to prevent rain from directly entering the attic. High winds can drive rain upward through some vents, allowing water to enter the space.

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