How to Wire an Attic Exhaust Fan

Lead Image
  • 1-4 hours
  • Intermediate
  • 1-100
What You'll Need
Wire stripper
12 gauge electrical wire

An attic exhaust fan is used to cool off the attic area when the sun heats up the roof. It can keep the entire house much cooler by blowing the hot air out of the attic.

After the attic exhaust fan is installed, it will need to be wired to an electrical outlet for power. It is controlled through the use of a thermostat that automatically turns the fan on when the attic reaches a certain temperature and then off when it drops below a certain temperature.

Turn Off Power to Outlet

The easiest way to wire an attic exhaust fan is to tie it into an existing junction box or electrical outlet. Locate a nearby outlet. Turn off the power at the circuit breaker for that particular outlet. You can easily check this by using a voltmeter on the outlet. If there is a reading, you will need to turn off the correct breaker.

Remove Outlet

Use a screwdriver to remove the screw that secures the faceplate to the outlet. Once that is removed, loosen the screws holding the outlet to the wall and slide it out of the box.

Connect Wire to Outlet

Run one end of the wire in through the back of the electrical box. Use the wire strippers to remove an inch of the insulation on the white, black, and green wires. Connect the white wire to the silver terminal on the outlet. The black wire will be connected to the bronze terminal. The green wire will be connected to the green screw. Chances are there are already wires on these sections to help you.

Replace Outlet

Once the wire is connected to the outlet, insert it back into the electrical box. Make sure that the wires are not kinked into the rear of the box. Secure it with the screws you removed earlier and set the faceplate onto the outlet.

Run Wire to Attic Fan

Run the wire through the attic to the fan. If the walls are uncovered, you will only need to staple the wires to the floor joists. If the walls are covered, you will need to remove a section of drywall to run wires through the studs.

Connect Wire to Attic Fan

Use the wire strippers again to remove an inch of the insulation over the wire for each of the three strands. Connect them to the attic exhaust fan with the white going to the silver, black to the bronze, and green to the green wire. Make sure that the connections are tight, or you will have electrical shorts that cause the fan not to work correctly.

Cover Wire Ends

Place the cover over the back of the attic exhaust fan where the wires are connected. This will protect them from moisture or sending any sparks onto the bare floor.

Turn on Power to Fan

With the wiring complete, you can turn the power back on at the circuit breaker. Set the thermostat and make sure that the fan works without any problems.