Anyone have a solar attic fan?

[timtim2008]

Anyone have a solar attic fan?

 

[djb2]

I noticed that our downhill neighbor got one over the weekend with their re-roof job. I was talking to the roofer (eye to eye -- it's *really* downhill) and he thinks very highly of them. They are quite effective. He's only had one call-back, for a minor motor whine during very sunny days. The supplier had a replacement motor with no push-back, and he said it took only a few minutes to replace.

There is a major cost savings from not needing an electrician to run new circuits.

 

[safetyman665]

People are installing those like crazy here. Residential PV installations are the latest craze to reduce energy costs here in Hawaii. Most PV installers recommend replacing your roof prior to adding a PV system if the roof is over 15 years old. When folks re-roof, they often opt for the solar attic fans which cool better than vents, use free energy, and require no wire runs in the attic.

 

[bglad]

Ok, now how about up north with the snow loads on the roof. Are there shut offs to prevent the fan from running when not needed.

 

[matt151617]

I designed my own actually, those are very expensive. A 5 watt solar panel plus a computer muffin fan venting through a pre-exisiting static vent- $25. It doesn't move a ton of air but it's better than nothing. I've also seen plans for a 15 or 20 watt panel powering one of those 12v car fans from Walmart- those move a good deal of air.

http://www.instructables.com/id/Solar-Attic-Fan/

In the winter, the angle/power of the sun usually isn't enough to move the fan much.

 

[kbs2244]

Just my opinion,
But I like the old turbine style more.
Far less to go wrong.

 

[Zippercat]

Had one at our prior home in northern Ohio. Worked great. Installed by friend who owned an insulation company and has installed dozens of them. He swears by them and says they should be set to run every day to help stop icemelt, and the resulting ice dams and backups. Claims there can be ice melt from solar gain even with below freezing airtemp.

 

[nwav8tor]

I've had one for a few years. It is solar powered but also has an electric b/u that simply plugged into a power tap on an existing light fixture. Mine has a controller that turns the fan on and off based on temperature and/or humidity in the attic. The house power allows the unit to run on cloudy days or continue to run after sunset. It was a fairly easy job to replace an existing static vent with the new solar fan unit...

 

[Bruce4310TX]

I have one it works great at least 7 yrs and still working, does a good job pulls lots of air makes it tolerable up there.

 

[Falcon67]

Just my opinion,
But I like the old turbine style more.
Far less to go wrong.

Until Hail beats the hell out of it and the neighborhood has to listen to TINK-TINK-TINK-TINK... every time there is a breeze. Lots of the turbines here, they last until a good storm makes them look like a Jiffy Pop bag beat with a ball peen hammer. I would do what Matt says - get a 9" radiator fan off eBay and pair it to a low cost solar panel.

Edit - this took 2 minutes:
http://www.amazon.com/dp/B003N8J6A6/?tag=atomicindus08-20
http://www.amazon.com/dp/B002HT09TO/?tag=atomicindus08-20

Package deal for DIY:
http://www.amazon.com/dp/B00B002WAA/?tag=atomicindus08-20

 

[timtim2008]

wow.. much cheaper ideal.

only $25 for 16" or $16 for 9"

thanks for the ideal guys.

anyone know how many watts @ 12v it to takes to run?

 

[rtcblc]

I've got one mounted on the side of the house the vents through the end wall attic vent. Bought it @ Costco about 3 yrs ago. Still working well. It replaced an electric fan. It works on temp so in the winter it doesn't turn on.

 

[rdsk8ter]

We install these all the time for customers they work better then a standard high voltage fan and have a lifetime warranty. Up to 60 watt 2050 cfm
http://www.atticbreeze.net/

 

[where2]

wow.. much cheaper ideal.

only $25 for 16" or $16 for 9"

thanks for the ideal guys.

anyone know how many watts @ 12v it to takes to run?

Read the "See more product details". Specs say it's an 80W fan and it "draws only 8A"??? Better buy a few of those 20W panels... It might not take 80W to actually start it running, but it won't move 700CFM without some current behind it.

Or say the heck with it all, and install grid-tied PV like I did.

 

[matt151617]

Here's a good how-to: http://www.instructables.com/id/Solar-Attic-Fan/

Keep in mind a 10 watt panel only produces 10 watts under perfect conditions; you might want to oversize the panel. Also make sure the panel is at the proper angle for your latitude and is facing south.