Holmes HM3501-U Cool Mist Console Humidifier with humidistat

I used to wake up with a sore throat every morning because AZ is soooo stinking dry. I would have to get up every couple of hours just to get a drink of water so I could breath since my throat was so dry. Now I can sleep through the night comfortably because there is actually enough moisture to keep me breathing comfortably. Absolutely love this product! It's a bit loud on high, but at the medium setting for my 2600 square foot house it works just fine. And it has a soothing hum to help me sleep. And the auto cutoff when the tanks are dry is a money saver too. A must have if you are sick of the dry heat.

I need a humidifier capable of humidifying a large room. This one has the moisture output capacity.
However, the design looks typical of a "Lab Bench Design" without considering the real bedroom situation. There are two design flaws: (1) The tanks need to be filled upside down. Yet, there is no flat surface on the top of each tank so it can stand upside down in a bath tub or sink. The user needs to wrestle each tank with both hands during the filling, and (2) The moist air shoots straight up with no deflector to guide the air flow. If you place the unit against the wall, you'll be humidifying a large area of the adjacent drywall. Tell me how many people plan to put this unit in the middle of a room and away from a wall.

I purchased the humidifier about one month ago.
There was 28%-35% humidity before in the small apartment (I have a quite accurate digital hygrometer). The Holmes humidifier could increase it quite quickly and keep it at the desired level. It doesn't leave any marks, the mist is really invisible.

After opening the box it was easy and fast to assemble it (actually, you only need to take out the 4 roller legs from the filter and screw it on the base).
It can store enough water to run for couple of days (of course, it depends on how much space it needs to humidify and what is the humidistat settings.)
The electronic control let's you set the humidity easily, however, you can't know the real value without an external hygrometer, because there is no display for it.
The humidistat works well, there a very small tolerance range. Usually I can keep it 43-50%. First time it was able to produce 60%, but I just decreased it because I don't need it.
The device has 3 fan speeds, the lowest one is very quiet, the medium is acceptable, the fastest one is a bit loud. I also experienced a relatively strong vibration, probably because of the fan is a bit unbalanced. First time I used the highest speed to reach the desired level of humidity faster, but after that it's enough to use the low or medium.
After one month the filter upper edges getting darker, probably because of the calc in the water. It seems that the filter lasts for 2 months.

There is one side effect, but it's how the physics works: it cools down the air around because of the evaporation so it's not recommended to place it close to a thermostat or in the bedroom.
I also noticed an interesting low hum sometimes and I realized that it comes from the tanks when they are close to empty. The tanks are vibrating because of the fan vibration and they act like an acoustic resonator box... well, it's not very loud and you can avoid it placing some small self adhesive rubber or felt between the two tanks to don't let them contact.

There is only one good thing to say about this humidifier: it puts out a ton of moisture! I have it in a large room and it can really make the room humid. It gets 5 stars for its primary job of humidifying.

Unfortunately, everything else about it kind of sucks. The biggest annoyance is the water chambers. They are horribly designed. They are big and heavy, which would be OK except there is no good way to grab them. When you turn one of the chambers upside down to fill it from a tub faucet, there is no way to grasp it once it is filled. It is actually painful to grab the sharp, hard edges as you awkwardly turn it right side up. Once you have it right side up, you can grab it from the top handle, but the handle can cut into your hand and is slippery when wet. Filling the chambers is an unpleasant experience.

The fan is also too loud. I have the unit about 4 feet from my couch in the living room, and every time I watch TV I end up turning the humidifier off. At least it isn't a whiny or high pitched sound. It is just loud because it is a big, powerful fan.

We've had this Holmes unit for a couple of months now, and it has fended off the winter dryness just enough so we don't constantly get static shocks. With our coal stove going constantly in a 2100 square foot house, it has been hard for it to keep up, but it has made some difference. It is reasonably quiet if you avoid the High fan setting. Our only complaint is that refilling the water - which we do once a day - is rather clumsy. The water tanks have to be turned upside down to fill them, and then you have to hang onto them because the tops are curved so they want to fall over. Silly design. Be aware that the tanks get HEAVY when they're full, and they're an armful. Apart from that, our only quibble is frequent replacement of the filters, but that's probably the fault of our hard water and our not-so-great purification system.

Two factors led to me this model: high output rate, and low power draw. This unit will add several gallons of water per day to the air when its very dry. Power usage isen't bad at all. Its just a fan. ( Momentarily looked at a Warm-mist heating element based model. Very high power usage )

I got this unit about 6 years ago. Its still working well. No maintenance required other than basic surface cleaning of the basin, flushing a little bleach and water in the tanks to sterilize every few weeks, and of course filter changes.

I say good, not great, but I really dont know how great a pure utility product can be. I am thinking of spray painting it black for the heck of it. Also thinking of shorting the humidistat connector to force the unit to stay on ( see cons ).

Wick elements do accumulate mineral deposits from hard water. That's just a fact of evaporating hard water. No filter can magically change that. Flipping the filter top to bottom every so often helps. I have a water filter ( under sink long life model ) that seems to help.

I just for the first time pried the top panel off and cleaned the fan and motor element out. It runs like new. ( it got a little noisy as dust
accumulated on the blades )
If you plan on not using the unit for a few days, be sure you empty the water out of it, and refill with fresh when you wish to use it again. Standing water gets funky real fast. Sometimes I will put a very tiny dribble of bleach in the water tank when I refill and let that solution run through the whole machine.

Pros: High output rate.
Very quiet at low and medium fan speed.
Rolls around easy when full, even on normal carpet.

Con: Noisy at high fan speed.
Filling tanks can be awkward in a tub or sink. ( They will stand up if you can lean them against something stable )
Sometimes I wish that it would stay running when according the humidistat says its humid enough at max

This is the 2nd Holmes humidifier I've owned. The first one lasted nearly 15 years, with the two storage tanks finally splitting apart as the plastic became more brittle with age. I looked at many other makes and models as possible replacements, but came back to the same Holmes model as the best of the bunch. It has a high water capacity, but by splitting the tanks into a matching pair, it makes it easier to transport the freshly filled tanks from the sink to the unit. HOWEVER, why could they not make the tops of the tanks flat so that they would sit more securely when inverted while refilling in the sink? Form before function is a poor excuse.

The motor is not too loud, the controls are simple and intuitive, and the air flow volume has a good range from just a whisper of air flow, to Hey! Who blew out the candle!

The filter is a tad on the expensive side, but by flipping it over every week or two, I can get by all winter with only one or two replacements. Using a water conditioner seems to help.

If the tanks had flat tops I'd jump up to 5 stars...

We replaced our 17 year old Holmes Humidifier with the same console style and model. It seems to be a bit louder than our original one however we're happy with it. It was out of stock at first but a couple days later it was available, placed the order and arrived sooner than expected! Happy to have it...

Works just as advertised. I use a water and scale treatment chemical with every fill. I put a couple of cork cushions between the 2 bottles to prevent rattling. Lift each of the bottles with 2 hands after filling so you don't drop them because the plastic seems kind of fragile. I put Vaseline on the gasket around the bottle's refill cap. Be careful screwing the caps back on to prevent cross threading. I might put Vaseline on the cap's threads as well. Sound level is acceptable at low and medium. I use the high setting only at night as needed but I also sleep with a room fan on to mask general noise.

When purchasing an evaporation type humidifier be sure to consider the costs of the replacement wicks. They are about $10 for the Holmes unit but can be around $24 for Honeywell's machine. The cost of operation go way up in that case.

One more thing. I got mine on sale for $60 plus $17 for FedEx shipping from Blaine's Farm and Fleet (www.farmandfleet.com).

I've been using this for about a month. It's in a 20 ft by 20 ft bedroom plus adjoining dressing area and an adjoining hallway. On the low setting and using only one of the tanks, this is producing producing plenty of humidity (well above 40%). As with all cool mist humidifiers, you have to take it apart every day to prevent mold etc. So you have to have a place to let it dry out. As in the past, I use a little vinegar either in the tub or in the tank to fight mold. A good tip from a review of another product is to very gently squeeze (don't wring) excess water out of the filter when you take the unit apart. This prolongs the life of the filter. The real test of this unit will be a few years from now to see if it is still functioning well.

This humidifier is easy to use and works very well. Have used it for about a month and no problems. We have the fan set at medium and it soon becomes just a background noise when it runs so you hardly notice it. Our home is 1,680 sq ft and it handles it fine. We have used a similar humidifier for years. The water tanks are easier to fill and replace than the previous unit we had.

My husband & I have been using humidifiers for some time but it seems that we end up purchasing new units once a year. This frustrated us, so I did my research and found the Holmes HM3501-U humidfier. It is capable of keeping large rooms, or a condo in my case humidified. I think the stats said something like up to 1300 square feet. With the double tanks you never have to worry about the unit running dry while you are asleep or out. The rolers on the bottom make it very easy to move about. I would recommend this product for purchase. The only thing I'm not crazy about is that the fan is a little loud on the high speed setting.

Wouldn't it make more sense to have the water refill cap be on top of the unit? I'd like to see a humidifier that you can fill from the the top (without lifting anything) and that comes with a hose that you can connect to the sink. Having to lug these odd shaped water tanks to the bathtub is a PITA!! I'm going to research other brands. If anyone knows of one like I described above, please post! -Thanks