Broan-NuTone35316 Galvanized Steel Gable Mount Attic Ventilator, 1600 CFM

On the hottest, sunny days in the summer, our AC unit would run constantly starting around 1pm and not shutting off until around 8:00 PM. We keep the thermostat at 77 degrees, unit kicks on at 77.5 degrees and on the hottest days the temperature in the house would slowly climb to as high as 79 degrees. The unit finally starting to catch up at 6pm or so and again, finally shutting off at 76.5 degrees around 8:00 pm. We bought this Broan fan to see if it would help. Climbing into the attack, the first thing I discovered was that the main flexible duct was leaking, in the attic, where it was attached to the duct board stack coming off the air handler. Also, the flex duct at the first/main distribution plenum was leaking significantly. The original air handler was installed in the attic and we had the replacement located in the garage when we had a new unit installed many years ago. Obviously, the "tech" did a shotty job with that duct work and re-working that first plenum. Checking the older duct work that was not re-worked, the other two smaller distribution plenums and duct work at the registers was sealed tight, no leaks.I had received the fan but held off on installation. I strapped and taped the leaking duct work and applied duct sealing mastic. With the duct now sealed, I wanted to hold off on the fan installation until I could determine whether my repairs were effective. What I found was that now, the AC would still run all day but it kept the home at 77 degrees. So I made progress. It was then that I decided that I should try the fan. The house has ample soffit area for air intake but there is no ridge vent. There are two large, metal louvered gable vents, approximately 24" x 15.5" at north and south ends. I installed the Broan fan on a 3/4" board using rubber discs between the mounting legs and the board in hopes of some noise reduction. I also used nuts and bolts to secure the mounting brackets to the fan housing as I had read that the blades may hit the included sheet metal screws. I installed the board at the gable end that resides over the master bedroom since we aren't in that room much during the day. The other gable vent would be over the living room area. I installed the board with fan by attaching to the vertical studs that frame the area around that gable vent. I used dense foam weather stripping between to mounting board and gable end studs for further vibration isolation. I installed horizontal studs between the vertical studs so as to box in the vent and force the air output of the fan to exit through the gable vents. I wired a double switch in the garage for a master on/off and a thermostat override. And a switch for shut off in the attic near the fan.The result ... The ac now cycles on and off even during the hottest, sunny days. It runs for a while, 1 1/2 to 1 3/4 hours but it finally keeps up and shuts off. The off cycle is fairly short, maybe 45 minutes before the AC is back on again but this fan definitely does what I had hoped it would. I need to have some more insulation added in the attic. That will reduce AC run time further and also increase the length of the off time. However, that is not something that we can afford to do at present. Rough estimate suggests that I have reduced AC run time by around 2 hours per day. Also importantly is less wear and tear on what is now an older central ac system that has been working hard for a lot of summers now.The fan runs from around 12:30 pm until 6:30 pm with no off time. I have it set to kick on at approx. 110 degrees. I don't expect to see a huge energy bill savings but 2 hours less AC run time should offset the 6 hours at 3+ amps that the fan draws. Maybe saving a few dollars per month during the hot summer months. More importantly is the reduced wear and tear on the AC and the fact that we are now have a comfortable temperature in the home, all day. The fan moves a lot of air and the large gable vent should be allowing full air flow, or close to it. I knock off one star because the fan is clearly audible inside the bedroom that it is located over. It's not overbearing but you definitely notice it. Without the vibration damping, it would most likely be noticeably worse. I'm not exactly young any longer so crawling through the attic isn't much fun but sealing the duct work was more work than installing the fan. Not a terrible job to do yourself if you can safely do some wiring (up to code). This was a very worthwhile project and long overdue. Aside from being a little noisy, the fan works well so far.

UPDATE: I got the screws, put on the brackets, and installed the fan. The screws do not interfere with the fan blade, so far at least. Something not mentioned in other reviews is that you'll need either a helper or some way to hold the fan and its housing in place while you nail/screw in at least the first nail/screw. I rigged up a stout bungee cord, which worked. The fan is working well, although it does make noticeable noise. I'm already used to it and barely notice. I definitely feel it is keeping the house cooler.How stupid is it to ship a ~$200 product without $1.38 worth of machine screws to attach the mounting brackets to the fan housing? A: Very, VERY stupid. And cheap. So I have to get in the car, drive to the hardware store, and return, to get the screws. Once I do and install the brackets, only then will I find out if the screw tips interfere with the turning fan blades (a problem other reviews have mentioned). If screws came with it, I would know within 5 minutes of opening the package. Decide for yourself if you want to encourage this annoying nonsense. Can't review the fan's operation yet 'cuz I gotta go get the screws. I'll update. Look for Throb (posting name).

First of all, if you are skeptical of the merits of installing an attic fan let me tell you that you such a unit will make a noticeable difference on the comfort levels of your home on warm and hot days. By keeping your attic cooler, you prevent trapped attic heat (which can easily reach 150°F) from soaking down into your living spaces, making your house cooler and easier to cool (AC doesn't have to work as hard) as a result.Now onto the review: this is a very powerful fan! I installed on a piece a plywood with a circular cutout to be sure that my gable vent was thoroughly sealed from air leakage. This little bit of extra work also made it easier to drag into position in my cramped attic and mount to the wall, as the plywood prevented the unit from settling in between joists in the attics unfinished floor.It was a sunny day when I installed, so the attic was heating up fast. Sweat was pouring off me. Once powered up, however, the rush of air felt chilly and it was only a matter of minutes until the attic temps dropped to the point that I felt like I was sitting outside with a nice breeze, not in a cramped, hot, dusty attic.If you are faced with the option, get a unit with a thermostatic switch. You'd be surprised by how often you can forget about turning the unit on or off, and the whole point of the unit is to take care of attic heat BEFORE it becomes a problem. The thermostatic switch takes the work out, as it makes the unit come on at a specified temperature and switches it off once the attic is 10 degrees cooler than that temp. I highly suggest wiring for two switches: a master on/off switch and a thermostat override switch. It is a bit more work, but it can give you finer control over operation. It also allows you to test the working of the unit if need be. You could even replace the override switch with a timer switch. That way you can set how long you want to the unit to run for, in case you easily forget about things like this unit running on override.The only downside (and it is a minor one) is that I'm surprised about the noise level this unit produces. When the unit is on and you are on the floor below the gable where it is mounted there is no question of if the unit is on or off. I do not know how loud the realm of this style of attic fan is, but compared to a solar powered roof-mounted fan I've installed there is a big difference in noise produced. That being said, however, the noise level while noticeable is not obnoxious.

It's very important to wear gloves when handling this obviously foreign cut fan shroud as it's dangerously sharp and left me seriously cut and bleeding. There was a day when this safety hazard wouldn't have met product standards at Broan-NuTone. Also, take caution to make sure the entire unit is mounted in a uniformly round shape, otherwise the fan blades can easily come in contact with the ends of the mounting bracket sheet metal screws. On a positive note the fan seemed powerful and effective and easier to attach power supply wires compared to others I've used.

Good basic attic fan. It will do the job, you kind of get what you pay for. I used sound isolation grommets when installing on the attic wall which kept the vibration transfer down, you can hear it in the house but it’s not too bad. A few items of concern, the fan is quite noisy on the outside of the house and you can hear it on the street more than you would think; the second issue is the thermostat on the fan is quite poor and it it needs to heat up by an extra 5-7 degrees Celsius before it kicks in.It gets the job done at this price point.

Came as expected. How good it is will be dictated by how long it lasts in the attic.First Nutone attic fan in another building going 45 years strong. That's the benchmark!

Easy installation and the blade design moves a lot of air very quickly. I'm very happy with this unit.