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What Are the Different Types of Attic Roof Fans?

Alexis Rohlin
Alexis Rohlin

Attic roof fans circulate and vent the hot air that naturally rises in a home during the day. They also work to remove moisture from the attic to prevent mold and wood rot from occurring. Using attic roof fans can lower the temperature of the rooms under the attic by 5° Fahrenheit (15° Celsius). Roof-mounted powered and solar-powered attic fans are the two main types of attic roof fans.

Some attic roof fans are installed on the roof of a building. They have a mushroom-like shape that is created by the fan's rain cover. The rain cover protects the opening of the attic roof fan and prevents precipitation from entering the attic. Some come with thermostats that automatically turn the fan on and off when the air reaches a specific temperature. A safety device known as a firestat turns off the fan when it detects a house fire, ensuring that it does not accidentally spread the fire throughout the house by feeding the blaze more air.

Some attic roof fans are installed on the roof of a building.
Some attic roof fans are installed on the roof of a building.

Solar attic roof fans utilize solar panels as a power source, making them environmentally friendly, or "green", while lowering the humidity and heat of a home. Solar panels collect sunlight and transform it into electricity that runs the fan motor. They come in three different styles, including a standard flat base, a curb-style base and a gable-mounted base.

Attic roof fans can help remove moisture and prevent mold from growing.
Attic roof fans can help remove moisture and prevent mold from growing.

Standard flat-base solar roof fans are installed on normal-slope shingle roofs. A curb-base solar roof fan is installed on flat, low-slope or tiled roofs. The curb-style solar attic roof fan has a "curb" or wall that raises it up off the roof to allow the fan to work properly. A gable-mounted solar fan can be installed in an existing gable vent on a home.

Other types of attic fans include gable fans and whole-house fans. Gable-mounted attic fans are installed on the triangular point of a wall, between the slopes of a roof. They often are mounted behind an existing gable vent in the home and can have automatic shutters that close when the fan turns off.

Whole-house fans consist of a large fan installed on the floor of the attic. They are set in a wooden frame installed on a hole that has been cut through the attic floor. A hinged shutter covers the hole. The shutter opens when the fan runs and shuts when the fan is off, preventing cold attic air from seeping down into the home during winter months.

Discussion Comments

mobilian33

A well placed whole-house fan can be used in place of central air conditioning during the summer months on all but the hottest days. These fans are great for saving on energy bills.

Sporkasia

Not only does a good attic roof fan lower the temperature in your attic, but more importantly the fan can reduce the moisture in the attic and help prevent mold from growing. Once mold gets a start it can be difficult and costly to remove.

Drentel

@Feryll - I think both the metal and the plastic fans can work. With the small plastic fans you will need more of them, maybe 2, 3 or 4, depending on the size of your attic. They cost less than the good metal fans so you are still ahead on cost with the plastic.

You want to be careful when you start cutting the holes to put in the fans. I had a friend who put his own fans in and they never fit correctly and he had leaks in the attic when it rained. If you already have a place to install a fan then you might want to use the setup you have and just buy a new metal fan to take the place of the old one that doesn't work anymore. This way you can simply slide the old one out and slide the new one in place.

Feryll

When you go into the attic in our house on a warm day, you can feel the heat attack you as soon as your head pops up above the attic floor.This is the primary reason I want to get an attic fan running up there. There is an old metal fan up there already, but the electrician we hired said we would need to replace it rather than attempt to repair the fan.

He suggested we get several of the smaller plastic fans instead of buying a new metal one. Does anyone have an opinion on the metal vs the plastic attic fans.

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    • Some attic roof fans are installed on the roof of a building.
      By: Monkey Business
      Some attic roof fans are installed on the roof of a building.
    • Attic roof fans can help remove moisture and prevent mold from growing.
      By: Mushy
      Attic roof fans can help remove moisture and prevent mold from growing.