Tuesday, May 29, 2007
Attic Fan Project
Equipment
1. Attic Fan - get the appropriate size of your home. Some fans come with a thermostat. I got mine at OSH with a thermostat and it cost slightly less than a similar size unit from Home Depot that didn't have a thermostat. Test this unit before you install it. Use a blow dry to test the thermostat if the outside temperature is not high enough. You can use a Romex cable and stick the other end into a 3 prong outlet. The small slot should be the hot wire, but some outlets are mis-wired. Test the outlet first.
2. 14 gauge or lower Romex cable - I used a 12 because I got it for free from my neighbor, but a 14 gauge is easier to work with. I didn't use any conduit. A Romex cable holds 3 wires inside, a hot, neutral, and an unshielded ground.
3. Staples - These are specially made for electrical cables. I got some cheap one that was basically a U shaped nail. Use these approximate every 4 feet to hold the cable. If you hire someone, they'll probably just leave the wire on the floor of your attic crawl space. But it's better to staple it somewhere out of the way.
4. 3/8 Junction box connector - Electrically junction boxes have little circle tabs that can be punched out. These connectors go into that circle and have a couple of screws to tighen the wire so it doesn't get pulled out of the box. You'll need one for the fan and another for the junction box you'll connect to.
I'll assume you already have a circuit with enough amps to connect to and there's a junction box in the attic for this circuit. If not, get an electrician to wire one up to the attic from the breaker box. It'll be rated for 15 amps, but the building code will probably only allow you to put 8 to 10 amps on that box. That's probably enough for a couple of ceiling fans and an attic fan.
5. Rubber Washers - these will greatly reduce the vibration of the fan to the rest of the house. I found some that were 3/8" thick and the fan is almost slient with these installed. Buy 8 of these, but you'll probably use less. Depends on how many mount points you use.
6. Electrical tape
7. Caps or twisters to connect the wires
Tools
1. Screw drivers - probably just Philips
2. hammer - if you plan to use staples
3. Wire stripper - check that it has 12 and 14 gauge. Strippers made for communication wires may not go that big.
4. Contractors knife - use this to separate the individual wires in the Romex cable
5. Voltage tester - I had a cheap one that shows if a circuit was live, but ended up borrowing one from a neighbor that shows voltage too. The electrician tester are great, because they're easier to use.
Steps.
1. Find a large vent that's easy to reach.
2. Find a junction box you want to connect to.
3. Measure the distance and make sure you got enough wire.
4. Mount the attic fan with the rubber washers.
5. Hook up the cable to the thermostat.
The unshielded ground should be screw to the metal chassis.
The black wire is generally used for hot and the other wire, probably white, is neutral.
You can use either wire for hot and neutral, but you may confuse the next guy that comes along.
See steps 9 to xx.
6. Ran this wire to the junction box and staple the cable every 4 feet or so.
7. Open the junction box and test the cables to identify which is hot and which is neutral. Again, the convention is black for hot, but test it to make sure. Sick one probe on ground and the other on hot. Run the same test again, but instead of ground, put the probe on netual. It should read 120V. If it's not 120V, get an electrician to look at it.
8. Turn the power off at the breaker. Professionally like to work with hot wires, but I'm not a pro.
9. Knock out one of the circular tabs in the junction box and add a connector.
10. Thread the cable thought the connector.
11. Separate the individual cables with the knife. About 4 to 6 inches will do.
12. Strip about 2 inches of the insulated wires.
13A. If the wire you want to connect to is already connected to one other wire
a. Disconnect it or cut off the connected parts and strip if necessary
b. line all 3 wires up and tape them together about 2 or 3 inches from the ends.
c. Use a cap or twister to connect the cable.
d. Tape up any exposed wiring except for the ground wires.
13B. If more then 2 wires are already connected, I would suggest you cut one of the wires a few inches away from where they are connected and connect your wire here.
14. Turn the power on (at breaker) and see if the fan runs
Trouble shooting.
1. Use the electronic connected to see if the hot is wired properly going to the thermostat
2. Test the voltage between the hot and neutral and it should be 120
3. Test the connection from the thermostat to the fan. If this is off, then it just may be the attic is not hot enough yet. Try lowering the thermostat setting.
1. Attic Fan - get the appropriate size of your home. Some fans come with a thermostat. I got mine at OSH with a thermostat and it cost slightly less than a similar size unit from Home Depot that didn't have a thermostat. Test this unit before you install it. Use a blow dry to test the thermostat if the outside temperature is not high enough. You can use a Romex cable and stick the other end into a 3 prong outlet. The small slot should be the hot wire, but some outlets are mis-wired. Test the outlet first.
2. 14 gauge or lower Romex cable - I used a 12 because I got it for free from my neighbor, but a 14 gauge is easier to work with. I didn't use any conduit. A Romex cable holds 3 wires inside, a hot, neutral, and an unshielded ground.
3. Staples - These are specially made for electrical cables. I got some cheap one that was basically a U shaped nail. Use these approximate every 4 feet to hold the cable. If you hire someone, they'll probably just leave the wire on the floor of your attic crawl space. But it's better to staple it somewhere out of the way.
4. 3/8 Junction box connector - Electrically junction boxes have little circle tabs that can be punched out. These connectors go into that circle and have a couple of screws to tighen the wire so it doesn't get pulled out of the box. You'll need one for the fan and another for the junction box you'll connect to.
I'll assume you already have a circuit with enough amps to connect to and there's a junction box in the attic for this circuit. If not, get an electrician to wire one up to the attic from the breaker box. It'll be rated for 15 amps, but the building code will probably only allow you to put 8 to 10 amps on that box. That's probably enough for a couple of ceiling fans and an attic fan.
5. Rubber Washers - these will greatly reduce the vibration of the fan to the rest of the house. I found some that were 3/8" thick and the fan is almost slient with these installed. Buy 8 of these, but you'll probably use less. Depends on how many mount points you use.
6. Electrical tape
7. Caps or twisters to connect the wires
Tools
1. Screw drivers - probably just Philips
2. hammer - if you plan to use staples
3. Wire stripper - check that it has 12 and 14 gauge. Strippers made for communication wires may not go that big.
4. Contractors knife - use this to separate the individual wires in the Romex cable
5. Voltage tester - I had a cheap one that shows if a circuit was live, but ended up borrowing one from a neighbor that shows voltage too. The electrician tester are great, because they're easier to use.
Steps.
1. Find a large vent that's easy to reach.
2. Find a junction box you want to connect to.
3. Measure the distance and make sure you got enough wire.
4. Mount the attic fan with the rubber washers.
5. Hook up the cable to the thermostat.
The unshielded ground should be screw to the metal chassis.
The black wire is generally used for hot and the other wire, probably white, is neutral.
You can use either wire for hot and neutral, but you may confuse the next guy that comes along.
See steps 9 to xx.
6. Ran this wire to the junction box and staple the cable every 4 feet or so.
7. Open the junction box and test the cables to identify which is hot and which is neutral. Again, the convention is black for hot, but test it to make sure. Sick one probe on ground and the other on hot. Run the same test again, but instead of ground, put the probe on netual. It should read 120V. If it's not 120V, get an electrician to look at it.
8. Turn the power off at the breaker. Professionally like to work with hot wires, but I'm not a pro.
9. Knock out one of the circular tabs in the junction box and add a connector.
10. Thread the cable thought the connector.
11. Separate the individual cables with the knife. About 4 to 6 inches will do.
12. Strip about 2 inches of the insulated wires.
13A. If the wire you want to connect to is already connected to one other wire
a. Disconnect it or cut off the connected parts and strip if necessary
b. line all 3 wires up and tape them together about 2 or 3 inches from the ends.
c. Use a cap or twister to connect the cable.
d. Tape up any exposed wiring except for the ground wires.
13B. If more then 2 wires are already connected, I would suggest you cut one of the wires a few inches away from where they are connected and connect your wire here.
14. Turn the power on (at breaker) and see if the fan runs
Trouble shooting.
1. Use the electronic connected to see if the hot is wired properly going to the thermostat
2. Test the voltage between the hot and neutral and it should be 120
3. Test the connection from the thermostat to the fan. If this is off, then it just may be the attic is not hot enough yet. Try lowering the thermostat setting.
# posted by Mack @ 10:57 AM 
