PureGuardian R4500 Refurbished 120-Hour Ultrasonic Humidifier with Warm or Cool Mist, 2.5-Gallon

This Ultrasonic humidifier is exactly as promised. It humidifies my master bedroom (approx 300 sq ft) with high vaulted ceilings. There are some negatives but I feel the positives out weight the bad. Nevertheless, let's talk about some of them.Negatives:1. It is a little inconvenient to add water to the tank.2. Sprays a white powder when using regular water (so use only distilled water or buy a filter which is sold separately)Positives:1. Humidifies2. Hot and cold setting3. Large tank to hold a lot of water4. Easy to clean5. Looks good6. Has a night light you can turn on/off

I have bought two of these units refurbished. One I got over a year ago from a sellout site and it's still a workhorse! It has gone two whole Winters of being pretty much constantly on and still operates the same as when I got it. There are so many things that I like about these humidifiers!I like the retro look of the big round front. The blue light that you can turn on/off is visually pleasing (to me at least). I really like the specific mist control that you have with the analog dial instead of relying on presets toggled by a button. The misting nozzle can be set to spray in two different directions which is very nice for getting more coverage. You can toggle from cool mist to warm mist (the warm mist actually feels warm too). It is very easy to remove the tank (just lift up) and filling is no problem if you have a wide open sink or bathtub. Because the tank holds a good amount of water it definitely is pretty hefty when full. It's not a problem for me as a fit young man, but may be for someone feebler or with arthritis. It's worth it to me because it humidifies for a lot longer between fillings than many of the humidifiers on the market.These humidifiers really put out moisture! I used to have it in a 15X25 room that had a large sliding glass door that the sun would shine in for the whole last part of the day making it extremely hot and dry. This unit had no problem keeping that room around 50% humidity constantly on about half strength. I now live in a 1000 sq. ft. open loft plan wooden house. I started out using just the one and put it upstairs to keep the bedroom more humid while sending some humidity to the lower level. At full blast it was able to keep the humidity level of the whole area at about 17-30% humid with the upstairs area staying slightly more humid and the lower great room slightly less (this also depended on the weather conditions outside). I was impressed that just this one humidifier could at least keep the house from absolute dryness, but another would be needed to get the humidity at appropriate levels for a wooden house with tons of plants.I ordered another refurbished one from Amazon and it works and looks just as well. It is an updated model from the other one I have and has minor design changes (nothing bad). The two working together (one downstairs and one upstairs splitting between the loft and down into the lower level) have no problem keeping the whole house at between 30% and 50% humidity (even more if I wanted). That's usually running each at 75% strength. Once again this is also very dependent on the weather outside (lots of wind will suck the humidity right out of a house), but in my home set-up they work brilliantly!The only maintenance is cleaning the unit of grime, algae, and calcium scale or deposits (if you have hard water). Depending on use and hard water content you probably only need to do this once a week. Mine collects tons of calcium deposits that will eventually block the inner vibrating disk from producing mist if you let it go. I use half water/half CLR and fill the reservoirs completely for a few minutes and that works wonders. You can also use white vinegar, but I think CLR works better. Just make sure to rinse the reservoir really well with fresh water. (You can avoid the calcium deposits and scale if you use solely distilled water or reverse-osmosis filtered water)I know that there are some defective units of these out there, but I have had nothing but good use out of them. Every once in a while the new one will (usually after cleaning) produce a spout of water from the disk instead of mist. However, after I let it run for awhile it starts to produce the mist again so the problem fixes itself. I'm not sure if this is from a voltage issue or if it's a physical issue of the vibrating disk, but it stops doing it after 15 mins. Other than that, I highly suggest these Pure Guardian Humidifiers! Especially if you only want to change the tank once a day instead of 2 or 3 times a day. That large tank is excellent!Update as of Nov. 2014: My now 3 year old one works no problem still as long as I keep the calcium buildup down. The newer make one I bought still works, but with issues. Sometimes it doesn't properly drain into the misting reservoir causing the humidifier to sometimes do nothing until it is given a slight rock or lift of the tank. This also sometimes causes the humidifier to shut off and on over and over by itself because the sensor detects not enough water is collecting. I can't figure out why it's not draining properly precisely, but I think it just has to do with how the inner connecting pipe between the reservoirs is angled. With some coaxing it still runs fine and packs out the moisture. Still very worth the money, but just wish the newer make one functioned on par with the older make one.*Problem fixed* I cut out a section of plastic from the little conical cylinder that sticks out from the tank and now it appears to not have that issue anymore. I'll explain further if anyone needs further clarification.

I'm sad to say I will be returning this humidifier ASAP! I'm assuming that these "refurbished" models are just not worth the money. My unit is defective. The first thing I noticed was that the lid on the tank does not make a complete seal so it leaks every which way while I try to place it on the unit. I was willing to overlook that so long as everything else worked fine. I was excited to see how much mist was coming out as soon as I turned the unit on. I tried to lower the mist setting but it seems there's only one setting. SUPER HIGH. I watched it for a few minutes before going to bed and it seemed great! There was almost no machine noise, but a few dripping water noises. Well, when I woke up in the middle of the night to check on it, I stepped on a huge wet spot. And then another wet spot and another! The WHOLE floor was soaked!!! Here I was, in the middle of the night mopping up the mess from this unit. Very disturbing! I can only imagine how the floor would've looked if I slept through the night! I want to clarify that the floor was soaked from the mist and not from the unit leaking. Unbelievable!

EDIT 9/15/2015--I reiterate all of my "PROS" below; however, this unit leaks like crazy. I sent it in for repair, and after receiving it back after only a few days it was leaking again. It seems to leak less when the tank is full (maybe this has to do with some weight pushing down on a seal somewhere?) and when on an absolutely perfectly level surface, which, I'm sorry to say, is nonexistent in your average home. Even the slightest partial degree of an incline makes this thing leak.-----------------------------I went through three humidifiers before this one including the very popular Crane, and finally, this PureGuardian has done the trick!PROS:-Obviously, the 2.4 gallon tank. Although instructions specify you should empty any humidifier once a day to prevent mold and bacteria build-up, I run this every night and the ability to use it for two to four nights at about medium output without refilling is a huge plus for me. I am just careful to clean it appropriately every month. Additionally, you can use the Aquastick (GGHS15).-Yes, the tank is somewhat heavy when it's full, but PureGuardian has provided lifting handles for rightside up and upside down carrying of the tank which makes it no problem.-I love that the adjustment knob and the power knobs are SEPARATE so I don't have to find the perfect output level each time I turn on the unit.-The nightlight is the perfect brightness to get a little bit of light when I have to get up in the middle of the night and don't want to disturb my husband.-The output direction is adjustable on a small and large scale by twisting the two output nozzles. The smaller output nozzle can be moved independently of the large output nozzle, providing the ability to push the mist in two different directions, if desired.-Good instructions! Something you appreciate after buying a few products with a poor or no instruction manual.CONS:-The power light indicator is BRIGHT. I took the faceplate off and covered it with a bit of electrical tape which solved the problem.-There is a periodic bubbling sound as pressure equalizes in the tank when water flows from the tank into the base. This is noisy enough to drive my husband crazy, but I've grown used to it.-The output nozzles are difficult to rotate. I can't quite figure out why.OTHER:-I did notice a "water dripping noise" started after about a month of use as complained by another reviewer, but as soon as I cleaned the metal disk per the instruction manual, it completely stopped. Humidifiers require maintenance! (I also noticed this sound when I had the unit on an unlevel surface. Fixed by moving it to a level surface.)-The base on this thing is huge. I personally prefer it to take up less space on my nightstand but I'm willing to take it for the larger tank.-Other reviewers have mentioned problems with quality or the unit being "clearly refurbished", but I wouldn't have been able to tell this unit wasn't brand new if I didn't know already. For the unit I received, the quality is well comparable to a new unit.-The unit I received does look slightly different than that pictured in the Amazon stock photo. The knobs are all in the same place but the indicator lights look a bit different.-Reviews for all sorts of different humidifiers complain about white dust build-up around the humidifier. In these cases, the water being used is too hard and distilled or filtered water should be used instead.-Reviews for all sorts of different humidifiers also complain about water build-up on all the surfaces near the humidifier. Unless the tank is leaking, this is because the humidifier is on too high. There's already too much moisture in the air and it cannot all be absorbed, thus it collects on surrounding surfaces. Just turn the unit down and the problem will be solved.