As the manual version of the U650, the Air-O-Swiss U600 humidifier is a quality home appliance for
those who want relief from dry air in the home. With manual controls and fewer digital features, the AOS U600 is a compromise that
delivers the same great humidification results for someone looking to stay under the $200 mark for a home humidifier. A full range of
features make the U600 a hygienic humidifier while the results cannot be beat. When stacking this model up against the competition,
this is what we found.
What I like about the Air-O-Swiss U600 Humidifier
For most of us, performance is job #1, 2 and 3, and with the Air-O-Swiss U600 you won't be disappointed. The tank holds just under
a gallon and a half of water, and this is about in line (perhaps a little smaller) than comparable models. If your the room you are using
the humidifier in is very dry, like mine is, you can push about 3.5 gallons of moisture back into the air over a 24 hour period. In my case,
I was going through about 2 gallons of water a day, and the results were hard to argue with. Generally, in the downstairs area where my bedroom
is, it gets extremely dry from October through January. For me this means trying to go to sleep breathing through my nose since when I wake up
in the morning, I'll know in an instant if I was breathing through my mouth all night. The air is so dry that I often wake up with a sore
throat and my sinuses feel like I've been trekking through the Mojave all night long. With this Air-O-Swiss humidifier there is a significant
difference in the mornings. I don't wake up with a sore throat or dry sinuses, and the change is very welcomed! Over the course of a week,
I also I use less lotion on my arms. Without a quality humidifier, dry winter air usually brings about dry skin on my arms, but after using the
AOS U600, consistently, that nearly completely went away. So when it comes to actual performance, the U600 is a perfect fit in relieving these
Though it lacks the digital controls that come standard with the U650, the Air-O-Swiss 600 humidifier has to simple dial controls and
some indicator lights. With the dials you can set the desired humidity level as well as the mist output. The hygrostat is fairly accurate and
was only off by about 1.8% when compared to an independent hygrometer. The indicator lights let you know when the tank is empty as well as when
you have the preheat function turned on. Filling the unit is simply and consists of removing the tank and filling from the bottom. Regular
maintenance consists mainly of wiping down the unit, descaling with EZCal when necessary and replacing the demineralization cartridge
The demineralization cartridge basically acts as a water filter. It attaches to the inside of tank, and as water passes through, mineral
impurities are filtered out. This helps to keep mineral content from being vaporized and dispersed throughout your home, and by being treated with silver
ions, the housing of the cartridge naturally prevents microbe growth. The ultrasonic diaphragm is coated with titanium to increase longevity, and included is
a small brush to use with EZCal in removing any mineral build up from the internal components. While some of this may sound very technical in
nature, the actual maintenance is simply while the functionality is top notch.
As an ultrasonic humidifier, the Air O Swiss U600 using a rapidly vibrating diaphragm to create ultrasonic vibrations that turn normal
water into a mist. This model also has an optional preheat function that will warm the water before turning it into mist. This works to
inhibit the growth of microbes with actually boiling the water. And unlike humidifiers that boil water, ultrasonic technology is
much safer and actually quieter. The AOS U600 is nearly silent and did not disturb my sleep at all.
The preheat feature is also what makes this a dual mist humidifier. When the preheat is active, the water is heated, then as it is
dispersed it cools to a temperature of just over 100 degrees as it is released into the room. The slightly warmer temperature helps to
keep the room temperature consist without the use of dangerous boiling system. In cool mist mode, the Air O Swiss U600 humidifier simply vaporizes the water at room
temperature, but as with creating any mist, as it turns from a liquid to a vapor it cools. Cool mist or warm mist - it's all just a matter
of personal preference.
What I do not like about the Air-O-Swiss U600 Humidifier
After testing the U650 and U600, I must admit, I missed having a digital readout of the current relative humidity. For most people though,
this isn't a big problem since it's really all about being comfortable. After using the Air-O-Swiss U600 for a couple times, you'll get a very
good idea of what settings are most comfortable for you.
I really wish someone would make a humidifier with a handle. Most come with handles built into the water tank, and this can be a bit
deceiving if your are moving the humidifier from place to place. After going through this a couple times with other models, take care
NOT to grab the handle and think you're picking up the whole unit. That... can be messy.
In all, the AOS U600 ultrasonic humidifier was an excellent value. The performance and features made it easy to use but efficient. The attractive
design of this home appliance allows it to easily fit into nearly any room, and a 3 year warranty is one of the best around. The Air-O-Swiss
brand has long provided consistent and durable home appliances with few drawbacks, and the U600 is no exception.