How to Install a Roof Attic Fan
An overheated attic can cause roof shingles to curl or bulges in roofing felt. It is also a cause of high cooling bills. Improper venting of an attic may result in trapped moisture, which will rot wood structures and roofing. A roof-mounted exhaust fan is an excellent solution to high attic temperatures and moisture retention. Roof-mounted fans are installed over an opening cut near the peak of the roof. A thermostat operates the exhaust fan year-round. Does this Spark an idea?
Other People Are Reading
Things You'll Need
- Measuring tape
- Circuit breaker
- Electrical wiring
- 3 wire nuts
- Electrical tape
- Support clamps
- Power saw
- Reciprocating saw
- Roofing nails
- Roofing tar
Instructions
-
-
1
Measure the attic and select the roof-mounted exhaust fan suggested for exhausting the correct square footage. Improve energy efficiency by installing two or three exhaust fans. One fan running constantly is less efficient than two fans running intermittently.
-
2
Situate the roof-mounted exhaust fan at the highest possible point on the roof, as close to the roof ridge as possible. Hot air rises to the highest point of the attic ceiling.
-
-
3
Verify the minimum size circuit breaker according to the manufacturer's specifications. Standard is a 20-amp breaker and No. 12 wire. Feed power from the service panel to the roof-mounted exhaust fan. The exhaust fan will require a hot wire, a ground wire and a neutral wire running from the service panel.
-
4
Cut a hole in the roof to accommodate the exhaust fan, using a power saw or reciprocating saw. The standard size required is 12 inches square; check manufacturer's instructions.
-
5
Tuck the aluminum mushroom cap under the head shingles, following the manufacturer's flashing instructions. Nail the mushroom cap with roofing nails. Paint with tar to seal the mushroom cap to avoid water leakage.
-
6
Mount the exhaust fan with the brackets and screws provided, working from inside the attic.
-
7
Turn off electricity at the circuit breaker providing service to the exhaust fan. Make the electric connections to the thermostat. Twist together the neutral to neutral wires, the hot to hot wires and the ground to ground wires. Screw on wire nuts; wrap with electrical tape. Follow local building code in supporting the electric feed lines.
-
8
Turn on the circuit breaker and test all electric connections to the exhaust fan.
-
1
Tips & Warnings
The thermostat will turn the exhaust fan on and off, year round. There is no need to turn off power to the exhaust fan during cool or cold weather.
Turn electric power off at the circuit breaker before undertaking any electric project.
