A Good Humidifier

I use the Holmes 3500 to humidify a 1500 sq. ft. home. I maintain a 40% humidity level (I use a humidistat) during the heating season. I leave the fan set to medium. I fill both tanks once per day.

I've used the unit for 3 months. I'm very happy with it. Noise level is comparable to a fan. Update: I've now used it for two heating seasons. I'm happy with it. 

There's been a lot of complaining about replacing the filter. Like anyone else I wish I never had to replace a filter too, but that's the price you pay with most evaporative humidifiers.

I have very hard water. I use both bacteriostat and water treatment. 2 cupfuls per tank. Cheap at Walmart.

I find the original filter to be very effective and efficient in providing humidty. Over time and use the black outer surface of the filter flakes off and that's kind of messy. After three months of use, I have noticed a drop in the filters effectiveness, but it is still working well.

You can get generic filters at a decent price at Walmart. Update: I've used a few different replacement filters by different manufacturers. Generally, they work well and last for about 6 weeks. 

The filler cap is conveniently large and has a well designed grip. The filler cap can tighten up as the tank empties. It can take some muscle power to open it when this happens. Update: Now the filler cap tightens so it's like opening a new jar of pickles. A dab of vasiline on the threads helped a little, but I can tell it's only a matter of time before either the cap or the jug breaks.

Sometimes, there is a slight buzzing sound. It has something to do with one tank being empty and the other full.

The overall design of the unit is bland, but it's very blandness keeps it from becoming a focal point.

The angled top of the tank is a stupid design flaw that makes the filling process tricky, but not impossible. Update: They fit fine in my  kitchen sink (pure luck, I'm sure), but a real hassle to fill in the tub because the tank falls over unless you hold it up.

The tanks and base are easy to rinse clean in the tub. I haven't tried it yet, but it looks like a major headache to get to the fan to clean it. Update: I still haven't cleaned the fan, but it's still pretty clean.

Update: I never installed the wheels on this unit. I keep the humidifier in a large, plastic, "under-the-bed" storage box in case the unit leaks. I recommend this method instead of using the wheels.

Some facts about the unit:
• This is an evaporative humidifier, not a mist humidifier. It does NOT create white dust.
• There are 2 tanks. Each tank holds 2.2 gallons which weigh about 20 pounds when filled. The base holds an additional 2 gallons (approximately).
• The filler cap only needs a very light touch to close.
• When filled correctly, the water level is 2 inches from the base's edge.
• It's excellent at maintaining the set humidity level, turning itself off and on regularly to maintain the set humidity level.
• The filter monitor on my unit appears to work very well.

Updated: March 2009