I've mounted several of these already. It's a cheap and simple attic fan both in construction and quality. Without a doubt, it really does lower the house temperature and keep the 2nd story cool. Supposedly, the benefit extends to prolonging the life of you roofing material. I understand the various critical review regarding warped housing and missing parts (they only give you four nuts and bolts to mount the clamp to the metal housing, you supply the rest). My advice is don't buy a used or return fan. I got a dud once with missing instructions, missing those four nuts and bolts and fan blade misaligned hitting the four braced posts etc... Had to do a return and wasted time.
The fan is not ultra quiet. The motor has a humming noise you can't miss but is not too bad. The best advice to minimize noise is to use rubber washers to isolate the fan from the board you're mounting it to. Rubber washers beneath the clamps, beneath the screws and washers holding the board to the house studs. You also need to use foam or rubber insulation strip around the perimeter of the board where it contacts the studs. Lastly, the price fluctuates depending on when you buy it. Buy it in off season for best price. It's a decent fan; only thing left is to see how the motor holds up...

This fan was the perfect solution to my over heated attic. I have a whole house fan to vent the heat from the house, into the attic and out through the a louvered vent on the gable end of the attic. During the hot summer month I need to run the A/C to keep the house comfortable, so the attic temp climbs up well over 110 degrees. I installed this fan right in front of the louver for the house fan. It is an open design, so it doesn't block the vent at all when the whole house fan is turned on. With the built in thermostat set to about 85 degrees, the fan kicks on and keeps the attic from getting crazy hot and I didn't need to cut any other exhaust holes in my house. Especially in the roof, where most attic fans vent to. Over all, this fan took literally about 30 minutes to install and wire. Works beautifully. There is no oil port on the fan motor to lubricate the sleeve bearings, but I think I will put a few drops down the shaft in the fall just to keep it in good working order. Great fan,, great price and simple to install. Definitely recommend it.

Installed OK but thermostatic switch did not work. I wired around it to ensure the motor worked OK and it did, so the problem is in the switch. After trying to troubleshoot it I just left the fan wired ON until I get a replacement switch, which I had to order from Amazon for $23 on prime. It is too much trouble after installing the fan to return the entire fan for credit, but I would like to return the fan switch for credit. However, Amazon does not permit a partial return so I guess I am stuck. So much for saving money on Amazon. I should have bought it at Lowes or Menards for slightly higher price and I would have come out ahead..

so far so good. only installed for about a week. quieter than I thought it would be. the blades took some bending, out of the package two of the four hit the back brackets, but they are flexible enough. also be mind full of the fasteners provided with the brackets, the heads are big enough that the blades contact them if not way forward or back

Our fan had not worked since we moved in several years ago. Installation was simple. Ours is on a switch as well. I left it on the manufacturers recommendation of 90 degrees for the thermostat but may tweak up a bit if it seems to be running too much. Installation took about 30 minutes with my son helping as the gopher and light man. Seems quite powerful as I could feel the draw when he flipped the switch. I could also feel and smell the stale attic air from outside. Quite impressed so far. Should help the air conditioning. Now for another layer of insulation!