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I rarely write reviews, but since this item didn't have any and we bought it recently as a new-baby humidifier, I thought I'd get the ball rolling with this one. We will use our humidifiers strictly for the baby, and although we've only been using this one for a week, I may update this review for a final verdict. After reading numerous other reviews (I'm aiming to pick up another one soon), I feel slightly more educated about the features that consumers might find more desirable in a humidifier.
What I like:
* It works. I wouldn't normally add this seemingly obvious comment as a plus, but after reading other reviews, it seemed worth mentioning. If it fails in the near future, I will update this comment.
* No filters or wicks necessary. I find this feature highly desirable no added costs.
* Ultrasonic technology makes this unit run silently. And I mean silently! It makes no significant noise. Perhaps with other technologies, the mist volume could be heavier and thus noisier, but the quiet nature of this unit is pleasant. Also, thanks to the ultrasonic tech, the vapor stream is virtually instantaneous when switched on, both on warm or cold. Granted, a minor point, but nice. Which brings me to another pleasant feature....
* Emits both warm or cold mist. And does so effortlessly. One of its 4 face buttons allows a quick and easy switch from warm to cold and back, and as mentioned above, the change is immediate.
* The H4600 has 3 variable spray options. Low spray is perhaps too low, but the option is there if you want it to run all day and night. There is also a dual headed mist nozzle which allows greater choice at aiming the mist, but I don't find this feature particularly useful since the mist spray isn't all that strong to begin with, but it's a nice addition, nonetheless.
* Silver Clean technology claims to fight mold and mildew in the water tank, allowing for healthier vapors and less cleaning. Too soon to judge this feature, but even if it works a little, it'll be helpful and it's better than not having it.
* Easy interface. The front panel has a simple 4 button operation with a lit display. I found this to be a welcome feature. One button is simply On or Off. Another is variable spray volume (low, medium, high) kind of like a fan speed. The third is to switch from cold mist or warm mist. And the last button is for the night light. That blue circle on the face of the unit is the night light. It's fairly bright, but blue, so it's not as bright as it might be otherwise. Since we use this for the baby's room, we like this feature. The lit display shows the volume of spray (in a too elaborate display of LEDs), the chosen hot or cold mist option, and an indicator for low water in the tank. (The humidifier turns off when tank is too empty)
What I don't like:
* It's a bottom filled tank, meaning you need to lift out the tank, unscrew the underside cap to fill it with water. Thankfully, there are little handles on both the top and underside of the tank, but I don't understand why humidifiers don't regularly feature a top filling portal. It would be nice to be able to add water with a pitcher poured in the top rather than removing the entire tank, filling it and replacing it. The tank is fairly generous at 2.4 gallons, but that makes the full tank over 16 lbs. when full. Okay for me, but not the wife. Also, and perhaps more egregious is that the output nozzles on top (where the mist comes out) are rounded and interfere with the tank laying flat on its back when being filled. You cannot lay this tank flat on its back to fill it so it must be held, or at least braced (unless I didn't realize that the output nozzles can be removed?)
* Cost. This is one of the most expensive room humidifiers I've seen. It does have a nice feature set, and so far, operates as advertised, so I think it's worth it, but the price may discourage potential buyers. My wife bought this one because it was expensive. She figured it HAD to be the best one. I'm not sure she was wrong about that.
NOTE: For some reason, the amazon page that displays this item lists the following as one of its features, "Digital display and clock with programmable run features". I believe this was a mistake taken from some other model that isn't being shown, although I've yet to see a humidifier with a digital clock on it. The picture amazon shows is the one we have. Well, I saw no such display or feature. There is no clock or digital display here, let alone programmable features. None that I saw, and I went through the manual. Perhaps this amazon model is one notch higher in this series of humidifiers and explains why it costs $20+ more than ours.
Conclusion: At first, I was disappointed with the design of the bottom-fill tank, and the poor placement of the output mist nozzles that I thought this was a deal breaker and planned on returning it. But then I came onto to Amazon to research and buy another model, and after rooting around the reviews, I realize that this model is actually pretty good. I don't think the tank lasts 120 hours (5 days!), but it lasts fairly long. So, aside from the tank filling procedure, everything else about this humidifier is quite nice. Recommended.
** UPDATE **
The rounded silver-colored output nozzle on the top of the unit can, indeed, be removed while refilling with water. That's helpful. It's still not perfect, as the tank doesn't lay flat on its back for refilling, but it helps. Also, the price of this unit has since gone up from when I wrote my review. We paid somewhere between $160-$180. Unfortunately, I don't recall for certain, but if you're thinking of buying this item, make sure you get the model with "Digital display and clock with programmable run features" as it states in the description. Ours didn't come with that feature, and it's the only thing that explains the price difference from what we paid. I can't say if the extra cost is worth it, but I hope that helps.
** Update II **
It's now January 2013 around 2+ years after purchase. The H4600 Ultrasonic Humidifier is still kicking, rather nicely, thank you. We use it primarily for the winter months. The internal basin of the base needs an occasional cleaning, but otherwise, all is well!
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I have an electric PTAC heater/AC unit. It provides amazing heat in the winter and dries the room out like you wouldn't believe making it so I have to wake up in the middle of the night to turn the heater off, or open a window to get moisture in the room. My last humidifier was OK, but it just didn't do enough to combat the heater. I put this on last night for the first time (and last night was snowing weather). The setting was on low, warm mist. Wow I slept so well. I didn't wake up to turn the heater off, I didn't wake up in the middle of the night to drink from my bottle of water (I go through 16-24 ounces a night). I HIGHLY recommend this product for people with dry rooms. The fact that it has a 120 hour refill cycle is awesome! It's also quiet!
Obviously since it's new I can't comment on cleaning procedures
My only negative feedback is the lights on this thing cannot be turned off. It's in my bedroom and I have the LED lights hitting my wall. Considering they have a night-light button that turns some extra lights on they could have just made that button turn all the lights OFF. I will end up taping a piece of cloth to the front to block the light.
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Minimal upkeep, as promised, but if you don't buy the additional demineralization cartridge, you may see some white dust on the machine and nearby furniture. Not as totally silent as I'd hoped... The 'glug-glug' sound is fairly intrusive in a quiet room (like a baby nursery). But overall, it's a good product. Only drawback for me is the lack of a hydrostat, so you can't set an maintain a desired humidity level.
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I've owned two other humidifiers that were
