Electric attic fan
1. Before you do anything, turn off the circuit breaker.
2. Then go on your roof and decide whether to put your new fan in the same spot as your old one. The fan should be placed as close to the ridge as possible because heat rises. It should also be on the back side of your house so it can't be seen from the street.
3. If you're going to put it in the same spot as your old one, you need to pull out all the nails or staples out of the flashing. They'll be located on the bottom half of the fan. You'll use a flat bar for this job. Make sure to take your time. It's common for people to rush through this and they end up tearing shingles, causing leaks.
4. Once the nails or staples are removed, loosen the shingles all around the top of the fan, and then pull the old fan out.
5. If you're putting the fan in a different location, you need to cut out a hole. To do that, you'll need to mark your spot from the attic... so your hole is in between the rafters.
6. Drive a hole through the roof so when you get on the roof, you'll know where to cut your hole.
7. Then, using a reciprocating saw, cut a 14 ½ inch hole in the roof. Start your cut at the bottom and work up.
8. WiresAt some point, you'll have to disconnect the wiring from your old fan. You can either do it from the attic or from the roof when you pull out the old fan. If you are uncomfortable with the electrical components in anyway, call an electrician. They'll charge about $100 to wire your fan. If you want to do it yourself, in most cases it's fairly simple because you already have the wiring from your old fan. So in most cases, you'll just have to attach the box to the existing wires.
9. Make sure you color code the wires. You can either do the electrical from the roof or from the attic. Which one you choose will depend on your attic space and height.
10. Put sealant all around the flashing of the new attic fan, and slip the fan up under the shingles.
11. Screw the bottom half down and put sealant on top of the screws so they won't leak.
12. If you didn't do most of your wiring on the roof, now you need to go into the attic and attach the control box to the existing wires.
13. Then you attach the control box to the joist. And that's it !
Attic FanMost new fans have thermostats that allows you to set the desired temperature so the fan will automatically turn on when it gets so hot in the attic. Some even have humidistats that will take the humidity out of your attic in the winter. Attic fans come in different sizes. Buy the size you need according to the square footage of your house. Also look at the warranty on the motor, some models will quit working after only a year and a half. Electric attic fans can cost up to $200. And you'll spend another $8 to $10 a month to operate it. But in the long run, it should pay for itself because it'll make your air conditioner work less, saving you up to 30% on your electric bill.