Panasonic FV-0811VFM5 WhisperFit EZ Retrofit Ventilation Fan with Motion Sensor, 80 or 110 CFM

Fan installed in a roughly 5x8 hall bath. Pleased that walking down the hallway doesn't trigger the fan, but it senses motion the second I walk into the bathroom. Extremely quiet-you can barely tell when it turns on, but it vents the room nicely after a shower.

I bought this thinking "retrofit" meant that I could just drop it in where my old (super) noisy fan was. I found out this is slightly bigger, which was a problem because the ceiling joists are unusually close where the original fan was installed. I eventually got it installed, and the difference in noise levels is like night and day! Really nice. I have to commend @WiggleWorm's review, however, because it was a step-by-step guide to disabling the motion sensor. While the motion sensor was totally effective at starting the fan, it shuts off too quickly (for our use at least). @WiggleWorm's guide couldn't have been easier to follow.

Installed two of these to replace old noisy fans. These fans have been doing great. The installation instructions weren't the greatest, but I figured out how to install them. Somehow I initially missed that you took off the exhaust/electrial box cover off to use the mounting bracket. I installed these from the attic too(if that helps people). Another tip is watch out for causing any obstructions. I read if the fan detects an obstruction, it will up the fan speed to full blast. I used a 4 inch damper, and that caused it to speed up, making it noisier. I knew it did this, but didn't think the 4inch damper would cause it to happen. In my install, it opened to 6 inch pipe, so I got a 6 inch damper(get Aldes best reviews I saw, and bought 2 of them) and that reduced any "obstructions" that the fan would encounter. Even on the low setting(80cfm) with 12 feet of pipe, it opened the dampers just fine.Another reason I got this was the motion sensor. It will run for 20 minutes, so reduced the need for a timer, and will work if I ever end up renting out my house.

Very quiet, and I now wish my electrician would have just hard wired it instead of putting a switch in - due to the motion sensor working so well.

Accidently bought the motion sensor version. The motion sensor stays on for a few minutes then needs motion to keep it on. I suspect by how the whole unit acts it is on some sort of bios run motion sensor, takes a few seconds to spin up when first turned on (like its booting up or someting). I thought the motion sensor was garbage and removed the entire motion sensor control circuit. Unplug the plastic connector inside the unit, this will remove power from the inside the unit. Unscrew the 2 screws holding the large black block that has the sensor cable wire coming out of it. Once this is down, open the black box, it has 2 clips, easy enough to open. Once its open, cut the Black, Blue and While wires on the top of the unit. Wire the Black to the blue, use a wire nut and some tape. Put the left over tape on the white wire just because you shouldn't leave wires about. Now the unit runs off my wall timer and the motion sensor is no more.

Works as advertised. Installation wasn't easy, as I had to build a box below the ceiling to mount it, as the space between the ceiling & underside of the roof (we have a "Santa Fe" style flat roof) wasn't sufficient, but once installed it works just fine. One can still hear a gently hum in the bathroom, but that's OK--tells you it is running; nothing outside, unlike the fan it replaced. We like the timer feature, as well. I'm glad I bought it and went through the effort to install it.

This is a terrible product, it is not quiet at all. I put it on 100CFM and then on 80CFM. There is no difference. No way it 0.5 DB as installation manual claims. It has a terrible noise of a 100 years old fan with some intermittent clunking.My vent is the correct size for CFMs and I hired an electrician to install it. What a disappointment. You can install it in garage or attic but not in the bathroom.

The motion sensor allowed this to be installed without running wiring to a separate switch.