Honeywell HCM-350 Review

Honeywell HCM-350 Review
Bottom Line

The Honeywell HCM-350 cool mist humidifier earns very positive reviews thanks to its effectiveness, ease of use, and ease of cleaning. There are few features, including no humidistat to monitor and maintain room humidity, but operation is simple and straightforward. It's a great choice for those with hard water: This is an evaporative humidifier so there are no issues with white dust settling on your furniture (the byproduct of minerals in the water) -- a drawback with competing ultrasonic humidifiers.

ProsEffective, Easy to clean, No white dust residueConsLarge footprint, No humidistat, Cool mist only

Breaking it down

Ease of use

Basic, but it works well. While the Honeywell HCM-350 may not have as many features as other top-reviewed models, reviewers say that it's simple to use -- just a single dial to set fan speed -- and efficient. The water tank has a wide mouth and is easy to fill -- and a sturdy built-in handle makes carrying the tank a snap. One feature it does have is a UV lamp to kill germs, but experts say that its effectiveness is dubious, making this more hype than help -- just as well as the bulb tends to burn out quickly and replacements are hard to find. There's a filter that needs to be periodically replaced, but it's inexpensive. One expert reviewer dings the HCM-350 saying that it is difficult to put back together once the filter is saturated because it won't hold its shape. One of the big pluses experts largely agree on is that the HCM-350 is designed to make ongoing maintenance easier than with most competing humidifiers. "The Honeywell didn't have any of the difficult-to-reach areas and small spaces that some of the ultrasonic humidifiers had, and we could easily fit our entire hand into the water tank to clean it," reports. As an added plus, the tank and the base are dishwasher safe.

Moisture output

Plenty of moisture for medium sized rooms. This humidifier is rated to humidify a space of around 500 square feet, though says it's best with rooms of 400 square feet or less -- which covers all but the largest rooms. The tank, to some reviewer's concern, holds only a gallon of water; because of this, the machine can go through two full tanks a day at maximum output. However, the positive side of this is that larger tanks are heavier to carry, harder to fill as they many not fit under some sink spigots, and more difficult to clean, notes John Holecek at


In the ear of the beholder. We saw split opinions regarding noise. As an evaporative unit, noise levels will certainly be higher than with an ultrasonic model. tests sound levels from one meter away and says that while the HCM-350 is loud enough to be noticed, it's not loud enough to be objectionable at top speed, and drops down to barely noticeable levels at medium speed. Holecek adds that the pitch of the sound helps minimize any issues. "It's a pleasant white noise that sounds like a box fan on a medium to low setting," he says. downgrades the HCM-350 quite a bit more over its noise, while conceding that, "During in-home testing, we actually found the Honeywell's fan noise at the lowest setting to be soothing and felt that some parents may appreciate the added "white noise" benefit." A third expert weighs in on noise level and rates it at "very good" at its highest fan speed, but offers little additional insight.


Well-made to reduce leaks. likes that the tank on the Honeywell HCM-350 is made from a single piece of plastic, without the seams that seem to develop leaks over time with other humidifiers -- and something that will help make sure the HCM-350 survives to the end of its generous three-year warranty, Holecek says. Because this is an evaporative humidifier, there are no issues with a fine white dust settling on furniture; a byproduct of minerals in water, especially hard water, that's unavoidable with ultrasonic models (even those with good filtration), and the source of lots of user complaints with such models. The HCM-350 is large compared to some ultrasonic models -- so large that it might be a tight fit on some nightstands. User feedback, while not universally positive, is better than we generally see with most humidifiers, including a 4-star rating at based on more than 1,500 reviews.

Our Sources


Honeywell HCM-350 humidifier, Editors of, Not Dated

The Honeywell HCM-350 is rated on its moisture output, convenience, noise level, efficiency and performance when filled with hard water. It receives an overall score, which can be compared to other humidifiers designed to work in a similar-sized room.


The Best Humidifier, John Holecek, Jan. 16, 2015

After hours of research and rounds of hands-on testing, the Honeywell HCM-350 emerges as the best humidifier for most people. "This machine combines solid performance with a virtually leakproof, dishwasher-safe reservoir," note's John Holecek. He also applauds how easy the HCM-350 is to fill and clean. Though the HCM-350 is rated for 500 square feet, Holecek says that it's best in rooms of 400 square feet or less.


Honeywell 350 Review, Ellen Baker and Editors of, June 14, 2015

The Honeywell HCM-350 lands in the middle of the pack in testing at Testers like the effectiveness and ease of cleaning, but are disappointed in the noise level, size, and lack of features.


Honeywell Germ Free Cool Mist Humidifier, HCM-350, Contributors to, As of October 2015

The Honeywell HCM-350 cool mist humidifier earns a rating of 4 stars following around 1,575 reviews. Some reliability complaints are seen, as are complaints that the filter needs replacing too often and that the UV bulb had failed and couldn't be replaced. Most users, however, seem reasonably to completely pleased.


Honeywell Cool Moisture Humidifier HCM-350, Contributors to, As of October 2015

Though it's based on fewer reviews -- just over 105 -- satisfaction is even higher at The Honeywell HCM-350 earns a score of 4.4 stars and recommendations from 93 percent of owners.