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turbo6bar turbo6bar is offline
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Join Date: Apr 2000
Location: volunteer state
Posts: 5,620
Quote:
Originally Posted by HardDrive View Post
Maybe you should not be so focused on the cost, and think a bit beyond saving a few bucks.
Way to think with your emotions instead of your brain.

I worked the numbers for a 25 watt system "ready to go," and the time to break-even was 35 years. There are other means to save energy with far lower payback times: solar water heater, radiant barrier in attic, extra insulation, and numerous others. The energy savings on a 25 watt panel: 25 watts * 12 hours * 180 days/yr * $0.13/kwh = $7.02/yr. This is a very simplistic check that does not account for the cost of an AC-powered unit, but I did use a low price for the solar powered fan. $300. Many larger solar fans were well over $500.

IF I can get the cost down to under $300, it begins to look more attractive, particularly with a rebate from the government. Personally, I think the solar companies jacked up the prices to match the 30% tax credit. Screw that. I'll DIY if I must.

slodave, any info on the DC motor? I also think it would be a great benefit to run the fan after sunset to remove heat soaked into the attic, but that's not possible without a charge controller and battery($$$). Yeah...I AM focused on cost, but that's the reason for doing this: remove heat from attic to reduce A/C expenses.

Joe Ricard, I am up the road in TN, so my attic isn't much better than yours. I sprayed Sherwin-Williams E-Barrier (radiant barrier paint) and I am not impressed. It is not a true radiant barrier. The next house I build will have radiant barrier in the roof sheathing. THAT is a great investment.

Evans, going to check out the Costco fan. I admit to being pessimistic at this point. Seems like the best way to save/make money is to start manufacturing solar fans and reap the large profits.

Will report in when I have more info.
jurgen
Old 06-10-2009, 05:11 AM
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