Which attic fan is better?

Question

I am thinking to install an attic fan becuase it is getting very hot in my attic.

PVC housing, $86
http://www.ventingdirect.com/productDetail.cfm?cPath=&productID=350

Aluminim housing, $256
http://www.ventingdirect.com/productDetail.cfm?cPath=&productID=N-RF68HRPSC&xView=

or
PVC but Solar Powered, $499
http://www.solarroofvent.com/Merchant2/merchant.mv?Screen=CTGY&Store_Code=001&Category_Code=SunRise1050

or
is there a better one that you know of?

The attic is 880 sq. ft.
I do have winter time here with 0F degree temps with snow.
I do not have trees above my house.
I do not have A/C.
I do use ceiling fans in the bed rooms.

Here is a nice story for the use of attic fans.
http://www.atticfans.com/

I have a hip root, thus I cannot use gable fans.

Answer 1

I'd probably go with the one that has the aluminum housing. Overall it is probably built better (better housing, better motor, etc) and will last longer. The solar powered one you are paying the high price just because it is solar powered, doesn't mean it is built well.

Answer 2

I had powered fans & when they pooped out I switched to Aluminum vents. The natural thermal current creates an air flow and my attic is no warmer then it was with the powered vents.

I do have an opening from my garage into the attic. About 20 feet long and three feet high so it has to help with air flow especially when the garage door is open.

The solar one worries me because it only develops 15 watts. I think you are paying a lot of premium for a less efficient unit.

Answer 3

If you already have eave vents which are on the attic walls, there are less expensive models you can purchase at Lowes and Home Depot which do not require cutting a hole in your roof. Also, check whether your roofing has a warranty which you may be voiding by doing so. I have one of those fire proof concrete roof with a warranty that I would void if I cut a vent through it.

But, we have very large attic vents for airflow on two sides of our home. The unit we purchased mounts in front of one of those vents and draws the air out through the wall of the attic rather than the roof. It is thermostatically controlled so it automatically turns itself on when the temperature in the attic reaches 90 degrees. It works extremely well and you can feel the difference particularly in the second story of our home. We don't really ever get below 35 degrees and have temps exceeding 110 degrees in the summer. I have not used my AC since we installed it and the temperature is usually maintained at 74 degrees downstairs and 76 degrees upstairs.