What are the Best Tips for Attic Fan Installation?

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  • Written By: Dee S.
  • Edited By: Jenn Walker
  • Last Modified Date: 15 February 2019
  • Copyright Protected:
    Conjecture Corporation
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Attic fan installation may, at first, appear like a difficult task; but, armed with a few basic carpentry and electrical skills, it can be accomplished. Some tips for attic fan installation are designed to save the installer money. For example, some areas do not require the presence of an attic fan, and some attics are designed in such a way that it is necessary to calculate the size of fan needed to cool or provide exhaust in an attic. In addition, there are tips designed to teach people where to place the attic fan and how to cut the roof and install the fan.

In general, most people attempting to install a fan in the attic will need an extra set of arms, making a partner essential. In addition, a few tools will be necessary to complete an attic fan installation project, such as a ladder, utility knife, drill, hammer, saber saw, pliers, and screwdrivers. For safety, many people use roof jacks to give them a secure place to stand, particularly if the roof is steep.


Before jumping into a project, such as attic fan installation, it is important to consider whether it makes financial sense. Specifically, attic fan installation is best for areas with warm climates. In particular, hot air from the attic may cause the air conditioning system inside the home to run longer than it normally would. By improving the ventilation in the attic, the air conditioner may need to run less, reducing costs for the home owner.

Once it is deemed financially feasible to begin an attic fan installation project, it is important to determine what type of fan will work best for a home. The general rule of thumb to calculate how powerful the attic fan should be is to multiply 0.7 by the square footage of the attic space. In addition, home owners should add 15 percent to that calculation if the color of the roof is dark. This is because dark-colored roofing absorbs more heat than light-colored roofing. The final calculation will determine the cubic feet per minute (CFM) of air that an attic fan must pull to work effectively.

It may be hard to determine exactly where an attic fan should be installed. It is advised to place it close to top of the attic to prevent hot air from collecting there. In addition, it is recommended to place the hole for the fan between two rafters that are near the center of the attic. Most people choose to drill a hole in the center of the area in which they want to position the fan. They may then stick an item through the hole to serve as a marker, so they can easily locate the correct location again from the outside.

From the outside of the roof, it is generally best to adjust the location of the fan so that a minimal number of shingles are cut. An outline of the fan may be drawn directly on the roof. Then, using a sharp knife, the shingles may be cut. Cutting through the sheathing may require the use of a circular saw as well. After eliminating any exposed nails, the fan may be dropped into place through the hole in the roof. The trickiest part of this portion of the project is making sure the fan is securely in place and protected with flashing, nails, and roofing cement.

For most individuals, the hardest part of an attic fan installation is the wiring of the thermostat and the fan. If a home owner is insecure, a certified electrician may be called to wire the fan to the electrical source of the home. Generally, the thermostat can be positioned above the fan, away from its air flow. Then, a cable can be run from an electrical box to the thermostat, according to the instructions that accompany the attic fan. Once the wiring is complete, it is time to test the unit and make sure that the attic fan installation was a success.



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