How to Install an Attic Fan

You may want to learn how to install an attic fan to help circulate air in the hottest part of your house. An attic fan can cut your home's energy costs and help to protect anything you might keep there if you use your attic as storage. Here's what you need to know to learn how to install an attic fan.

The first thing you'll have to do is figure out where you're going to install your attic fan. There needs to be an electrical feed for the fan. Most of the time you'll be able to hook the fan up via your attic's light. Then find the vent in your attic, which is essentially a grate covering a hole in your attic. Using the existing vent will save you the trouble of having to cut an entirely new hole in your attic.

Measure the fan that you'll be installing and cut the existing hole so that it can accommodate your attic fan. Now you'll install the fan's cover (yes, this does sound backwards). Once you've screwed the cover into the wall make sure you seal it from the outside with caulk. You will use the cover to figure out where to build the frame that will hold the unit in place.

To create the frame, measure the space between the studs on both sides of the cover. Cut two 2x 4s, one for each side, and nail them in place. You will need to cut a piece of plywood to mount to the frame. Most fans come with a template you can trace onto the plywood, but if yours does not, you can just place the fan on the wood and trace it. Cut out the hole you just traced. Once you've cut out the hole, center the fan over it and screw the fan's housing into the plywood. It's very important that you give the blade a spin to make sure it spins freely without hitting the plywood, cover, or frame you created.

In order to mount the fan to the frame you made, make sure you hold the fan so the correct side is up. The housing on the fan will indicate which side should be up. Move the fan into the frame you built and screw it into the 2 x 4s you installed, one in each corner. Next, make sure the fan is level. If not, take out the screws and make the necessary adjustments. If it is, install the rest of the screws to secure the fan to the frame.

The fan's thermostat comes in a metal box. Your next step is to mount it to the plywood. To do so, first take the cover off and remove the controller. There should be predrilled holes in the metal box. You will want to mount the thermostat on one of the lower sides of the plywood. Put the holes of the metal box against the plywood, level the box and screw it into place.

Now that everything is in place, you need to run the wiring to power the fan. Before doing any electrical work, make sure you cut the power to the electrical source. Run the wire from the electrical source (probably your attic light) to the fan. You will then run wires from the fan to the thermostat to power the thermostat. Replace the thermostat's cover and turn the power back on. Once the temperature reaches 95 degrees, your fan should kick on.