Air-O-Swiss 7147 Ultrasonic Humidifier

Researching humidifiers on Amazon was a somewhat tiresome exercise. Almost all products I looked at are subject to very serious complaints, most importantly noise, leakage, and lack of reliability. I decided to go with the AOS 7147 because most reviewers agree that it is really quiet, and because I liked the clean look and the features.Here is what I can report after about a week of usage (will update if anything changes over time):Noise level: Both my wife and I are extremely noise sensitive, but this unit can operate in our bedroom without affecting our sleep. Yes, there is a bit of a humming noise, but it is barely audible. Also there is a bubbling noise once in a while when water flows out of the tank into the tray. All-in-all, it seems about as quiet as can reasonably be expected.Effectiveness: We use the auto setting that lets the device decide the target level of humidity and the output level. This works very well and hassle free, keeping the room comfortably moist.Warm mist setting: I would recommend having it. Without it the room feels cool and damp. Even with using it there is a bit of a cooling effect, but it is acceptable.Filtering/water treatment: We did not see any white dust around the unit, which was a concern.Reliability/ease of use: No problems so far, straight-forward to operate, everything works as intended. I will post updates, if something comes up.Look: Matters more than you would think, because it is supposed to be three feet away from the ground and away from both heating and return vents. Inevitably it will end up in a rather visible place. This unit has a bit of a techy, but overall relatively neutral look, better than most.In summary, I am very happy with this unit.Update: After a winter, We are still happy with it. So we bought a 2nd one to be used in the office.Some tips on reducing the humming noise. Put a tray underneath the unit, then a thick sponge pad or similar cushion underneath the tray. The cushion dramatically reduces the noise level. The tray is very important. We first put the sponge directly underneath the unit, and that totally screwed up its moisture reading. We could watch the moisture level reduce from 50 to 49 to 48... to 37 in a few minutes and the unit cranked out steam like crazy. It seems that the unit needs to be placed on a hard surface to read the moisture level properly. Once we put a tray underneath it, the reading works normal again.

After a few years having to replace my humidifier every season or two, due to leaky seals and failing electronics, I decided to splurge on a nicer model, and this humidifier does not disappoint. It also comes with a three year warranty, so hopefully it should last a while.I chose this one primarily because it could make both a warm and cool mist. I've owned both types of humidifiers in the past, and liked the hot mist ones especially because they keep the house warmer. However they usually use a different type of misting element which actually boils the water. This is not very efficient, and builds up minerals in the water especially fast. This humidifier is different, it just warms the water in the bottom a bit, and uses an ultrasonic element to make warm (but not hot) mist. Note that it is not recommended to add oils to this humidifier like camphor/eucalyptus, and even if you tried, I don't think it would actually get hot enough to distribute them at all.The hygrostat is a great addition to a humidifer. You can set a relative humidity you would like, and it will stay on until it gets there, and restart periodically to keep it there. On auto mode, it even sets a comfortable humidity level itself, and adjusts the setting automatically when the temperature of your house changes. This prevents the room from getting too moist, and means you don't have to refill the tank nearly as often. It can keep the humidity in my home comfortable around 60% for about a week before I need to refill it.The tip where mist is released has a nice mechanism where you can point it in two directions at once, which is great for distributing mist all over a space. It generates more mist than any other humidifier I've used and is able to bring humidity up from ~30% to 60% in an hour or two. It is also exceptionally quiet, making only a quiet whir from the internal fan.This humidifier has two additional filters to keep its water supply fresh and clean. So far they seem to be working well. On auto mode I do not have to fill the tank more than once a week, but I have had no problems with anything growing in the water or mineral deposits even without frequent cleaning. The additional filters do make this humidifier more expensive to use, however, but It is probably still cheaper than having to replace the humidifier at the end of the year, like you might with a cheaper model. It is easy to refill in the sink and seems to have a very tight seal on the opening.My only complaints about the unit are that it's display, while quite informative, is quite bright, and I wish I could turn it off at night. I also think that it should turn its fan off when the mist stops on auto mode, rather than leaving it on all the time. It probably does this so that it can keep reading the humidity in the room, but perhaps it would save energy to just turn on the fan periodically to take a reading, instead of leaving it on at all times.EDIT 12/10/14: I was curious how much power it uses so I measured it with a Wemo Insight.Misting, Hot, Low Fan: 120WMisting, Hot, High Fan: 135WMisting, Cold, Low Fan: 35WMisting, Cold, High Fan: 45WStandby (auto), Hot, Standby Fan: 100WStandby (auto), Cold, Standby Fan: 14WTurned Off: 4WIt still uses 100W of power on standby with the heat on, so if you are going to leave it on auto when you are out of the house, I suggest turning off the heat!EDIT 4/25/15 It went through the winter great. I learned that with constant use, the filters do eventually need to be replaced to prevent scale from building up.I suggest buying demineralization granules and refilling the cartridge yourself, instead of buying whole new cartridges: http://smile.amazon.com/dp/B001IYMRHGThey also recommend descaling regularly with Air-O-Swiss EZcal, which worked fine, but I have since learned that Urnex is air-o-swiss's parent company, and they sell the same product, rebranded as DEZcal, for much cheaper. http://smile.amazon.com/dp/B00D1WHEY4EDIT 2/13/15After two years of near daily use, this humidifier has started to have an issue. The circulation fan motor, which is always on, has begun to make a "churning" noise, which is annoying enough to prevent me from sleeping. I decided to try and utilize my 3 year warranty from AOS. I now find that AOS has been purchased by another swiss company, BONECO. They claim to honor the same warranty as AOS so I gave them a call.The rep was nice and set up an RMA for me. I learned from him that I would have to pay the return shipping, which is unfortunate - but I guess unavoidable. He told me to email my receipt to their customer support and they would tell me where to send it back. That was a week ago. I still have not heard back from their support email. Starting to get annoyed and planning to remove some stars from this review for an otherwise stellar humidifier. (used to be 5 star...)EDIT 3/30/16After about 2 weeks and 3 additional emails, BONECO finally got back to me with the address to send the unit to. I had to pay ~$15 to ship it out UPS. After 4-5 days, a humidifier arrived in an different box. I opened it to find it was a different model, AOS 7144. I looked it up and saw that it is usually more expensive than the 7147, and had the same features with a larger case, so I decided to try it anyways. After a couple weeks with it, I think I want to go back to the 7147... the 7144 is almost as loud as my broken 7147 was... It would have been better if they just sent me the correct product. Overall I am very unhappy with the level of service from BONECO.