One of the three fans stopped working after a month. OK, I can live with that. But after three months, another one starts making a lot of noise, and then stops.

It's a basic appliance I'd expect to last for years, not months. I don't have to oil any fan I've ever bought, just keep it clean of dust. I don't understand these apologists who post here giving maintenance advice: it's a fan! I shouldn't need to take it apart to take care of it! I have had dozens of cheap fans that worked great for years without so much as a quick swipe with a duster.

The interface worked OK, and the one fan's still working. That's the only reason it has two stars.

EDIT: Tried contacting the company, no response, despite their alleged "5 year Warranty." I tried again, still nothing. Downgrading from two, to one star. Looks good on paper, not in practice.

I don't understand or agree with the few reviewers that stated this doesn't move much air. It certainly cools the room after sunset much more quickly than the ceiling fan because it's bringing in the cool outside air. Of course, for that to work, you need to open two windows so there's a way for the hot air in your room to escape. It's very quiet and doesn't disturb my sleeping at all. There's a nice thermostat function which will shut itself off.

Note that by "manually reversible", it's meant that the unit can be installed either way, blowing air into or out of the room, as there are controls on both sides. You literally flip the unit itself around. However, at least with my windows, only positioned to blow air in would readily fit with the screen in place. It will almost fit in the exhaust orientation by pushing against the screen. Luckily I have only half screens on my double hung windows so it's a non-issue. I only use this fan to bring the outside air in anyway. But it may be a consideration if you're planning on using this as an exhaust fan (e.g. cigar room).

It works very well, is quieter than my wall AC (which I would use in fan-only mode), and saves electricity costs over using active cooling. Indeed, I prefer to let some fresh air into the house. It's pretty light so it's not much of a hassle to add and remove from the window each day.

I can't speak on how long these will last yet, but I have a black model and a while model and they look even better in person than on the website. The black with the blue blades looks really cool, I wish I bought both blacks, but the white looks good too. The good is they look great and better than one of the big fans in your windows, this also helps stop people from seeing in if you have close neighbors. With my old larger double fan, I could see out and people could see in if they wanted. They are quiet and do the job, I am not sure about a "40% increase" over the larger double fans like it says, but its enough for a small to medium room, defiantly not a large room fan IMO. The only semi negative thing I can say is similar to most others, no simple reverse switch, you have to take it out and turn it around. Sure its not that hard to do, but they have controls and led lights on both sides and I am sure it cost more to add 2 of everything than a single reverse switch.

So I'm giving this a 2 star review even though honestly this fan should get 1 star and it should be recalled to fix some major issues.

So why the 2nd star? Because it's the smallest window fan out there and without it my bedroom would be too hot to sleep in.

What made it lose 4 stars, I should say what made it lose 3 stars... The NOISE, and it started on day 3, plus it really doesn't move much air.

Let me explain about the noise, this is my 2nd window fan and both had the same problem, this 2nd fan was just problematic almost immediately. The first fan lasted almost 3 years, about a year in the middle fan started making an annoying noise and the motor eventually died out, not a problem, I still had 2 more fans working but they both died right at the beginning of this summer. I considered other fans but none were this small and I already had plexiglass cut to fit the fan/window for the previous fan so why change things up. After putting the new fan in the window life was good... for a couple nights, then the noise from the middle fan started. I survived without the middle fan before so I just turned it off and slept with the other 2 fans running. Then about 2 weeks ago (a month after installing the fan) the fan on the bottom started making noise, the top/bottom fans are on the same switch so it was either a noisy fan or no fan, believe it or not in Southern California it's way too hot to turn the fan off so I've been trying to sleep through the noise.

So the breakdown:
Within a couple days of installing the fan I get noise from the middle fan.
Within a month from my purchase a 2nd fan begins making noise.
Currently, I try to sleep with the noise but always seem to get woken up at some point during the night.

I would like to add 1 thing, I have the fan installed vertically, when I place the fan horizontally it makes far less noise, but that's not the type of window I have, the fan needs to be vertical for me. This is not an excuse for the fan, the box says it can be installed either vertical or horizontal, so it should be working properly in the vertical position but it's not. I only added this point because if you plan on installing this horizontally you'll probably be fine for longer than a month, maybe even a couple years. But if you're installing vertically good luck, the noise will be a coming.

Bought the "Thin Window Fan, White Reversible" model BWF0502M-WM April of 2015.

Back looking for another one and decided to add a review. Important to note there are several versions of this fan so experiment with the drop down box to find one that suits. Reviews reflect all four versions of the fan so some may not be applicable to the one you need. If a review doesn't make sense for the fan you are looking at, it's probably for a different model fan.

THIS fan is reversible in that it has controls on both sides. The expanding component will let you make it fit a variety of sizes of windows with some extra spacers and an "accordion" slider. The latch on the slider is a little tricky to figure out but it does work if you put pressure on it with the window pane.

The three fans are controlled with the "speed" lever and it shuts one off for each reduced level. Which is sort of counter productive as some air just sneaks back the other way through the idle fans. I am perfectly happy with "full speed" all the time though. I don't use the thermostat portion of it so can't speak for that.

My fan is used for a kitchen exhaust fan to keep the smoke detectors from going off. Reversing is not an issue for me because I want it to blow air out all the time anyway. In this climate I do need to remove it frequently so while it took a little to learn I can flip the latch and pop it out and have the window closed in a few seconds. I have had no problems with rain getting in (or on the fan for that matter) and have left the fan running continuously for weeks at a time.

My fan has become caked with that same typical gray gunk that is the aggregate of cooking smoke and fumes over time. One of the fans now requires a poke or two to get it started due to this but they all work. I am here looking at another because I am preparing to take it apart to see if I can clean it. Wanted to verify I could get another before doing that. Since my first purchase, the fan has dropped in price so I may just buy a clean one.

It isn't a fast fan, and certainly not typical, but it is quiet and it moves more air than a vent hood for stove. Using it to keep the smoke alarm from going off for every cooking project it has worked beautifully.