Solar Attic Fan

Build a Solar Attic Fan for around $60 a piece.

You'll need

1. Small automotive fan that you would normally find mounted to the dash of a car or truck. Walmart in Lubbock Tx sells them for $11 a piece. They are 10 Watt fans.

2. 10 Watt solar panel, or panel with appropriate output for multiple fans if you so choose. Fans MUST run on DC electricity. You can't use a fan that you would plug into the wall. I have three fans hooked up to a home made solar panel that produces around 50-60 Watts.

3. Plumbers tape and screws for securing your fans to the rafters.

4. Wire Strippers, Crimpers, and side cutters AKA Dykes.

5. Various wire connectors like...butt connecters

Step 1 Parts Prep

Remove the cigarette lighter adapter from the power cord that goes to your fan. Strip the wires back enough so that you can connect them to your solar panel. Connect the positive wire from the panel to the positive wire on the fan. If you do not know which one is which, connect the panel to the fan and go out in the sun. If the fan blows air forward, you have it wired correctly. If it pulls air inward, swap your wires around. Test again and proceed to step 2.

Comments

[tomfoolry]

Great instructable! I was actually just researching solar attic fans when I came across this. I think I'm going to try making a couple and buying a couple more to see how they compare. Thanks a bunch!

[phrank70]

Could you use a 10", 12 volt, 12.7 amp radiator fan?

[cliffhiker]

Not with the panel indicated...
12Volt @ 12.7 amps works out to ~152 watts. (W = V x A)
So you'd need around a 160 watt panel or so.

That said, the fan should use less amperage depending on air restriction, etc. so if you plan to go that route you might want to measure the actual current (amps) draw under the intended use.

[solaralternatives]

O2cool makes small battery powered fans. Some operate 6v, some @12. I've found the work well on 15w solar panel, even on overcast days. I got mine @ walmart for a good price

[ddavis662]

Helpful info!
I was looking for a way to power a 12 volt fan to ventilate my camper.
I'm currently using trickle charger solar panel hooked to a 3 volt fan, but the panel will not power the fan unless it is in very direct sunlight.
I already have a 12 volt (lighter socket) fan andI just ordered a 10 watt panel from Amazon.com

[ddavis662]

I hooked the fan up to the panel and had the fan blowing hot air out of the bathroom vent in just a matter of minutes.

[xavito]

Thanks for the great article! I am adding a battery (UPG Sealed Lead-Acid Battery - 12V, 1.3 Amps, Model# UB1213). Can you please tell me if I need to add a charge controller? Also, can you please explain the connection at the battery? Do I need a special connector?

Thanks again

[fjpalacios1]

Great idea, especially for homes in South Florida.....working on this today!
Thanks for the instructions!

[zomfibame]

this is such a good idea, and nice n' simple.

[kelseymh]

Very nice! Not all Instructables have to be long and complicated :-) This doesn't really have a lot of detail or "back story" to it, but it is a great DIY project.

Any chance you could include URLs (links) to your sources for the fans and the PV panels? That would make it easier for someone else to reproduce it.