Can I add a fan to my roof vent?

[okmunky]

Is there a kit I can buy to add a fan to my existing roof vent or must I buy the whole thing? Is it better to bring the 12 volt power from an interior ceiling light, or across the roof?

[justaroamer]

Yes, many std. vents with fans simply add a small motor with a small fan to the bar bracing the crank handle, but they move very little air and would not be effective for moving enough air for comfort. Replace the vent with Fantastic Fan or similar vent with a large diameter fan blade and appropriate motor for best results.
Power from a ceiling light is OK, but own source is best. Be sure the ceiling light is not switched from a wall switch.

[wa8yxm]

You may find that there is already 12 volt to the fan cut out, but as to how to bring it your choice.

If I were adding a fan to a roof vent rather than use the fairly cheap perment magnet electroniclly noisy fan that is standard in those smaller fan vents I'd go with 1,2,3 or 4 computer fans, 12 volt, brushless so they do not mess up tv or radio, fairly quiet and 4 4" fans will fit nicely.

As for what I did.. Well when the motors on my bathroom fans quit. I replaced them with computer fans.

You do need to "Stand them off" the screen a bit (I put them above the screen where the original fan was) Many ways to do that stand off, I used craft sticks and glue.

They just sit there, not bolted to anything.

Or you could put a Maxx Air cover over it.. Now that... is a whole lotta fan. And what's more it can be left open in the rain.

[TQ60]

Search high volume fan, we found surplus high volume, 120 cfm fans that draw less than 1/2 amp list at $70 for $4.95

Added 4 to the kitchen overhead with a switch, factory fan reversable, 7 plus amps, new ones blow air in for just fresh air in storage, 400 cfm for 2 amps and not too much noise

[Muddypaws]

12v muffin fans come in all sizes. Generally bigger ones are quieter.

230mm computer fans are nearly silent and fairly cheap.

[mymillions]

We had a crank-type fan above the stove in the kitchen.(Now HOW do you open THAT often??)
We bought the comfort-aire fan with remote (and just anchored that to the wall,we liked the idea of no wires there).
The fan fits perfectly into the opening, and we just quick-connected into a wire running right thru the rafter there. It's workes just fine.
It's open when I want it open.
We have the rain sensor- but very glad we got the maxx-air cover, we had squirrels running around on top; while in Indiana last year. And even if the rain sensor lowers if it rains, it won't lower if you just plain forget it when you hit the road driving....it was not cheap, or very ingenius, but the quick-connect works.