JS H20 cool mist humidifier

As the air gets drier in the winter, many families turn to portable humidifiers to keep their homes feeling cozy and comfortable. The JS H20 ultrasonic humidifier featured in this review is one product that offers you two different options for keeping your home comfortable. It’s super quiet, compact, and it even has a secret essential oils compartment to help keep your home smelling fresh all season long.

Design of the JS H20 humidifier

In the box of the JS H20 humidifier, you’ll find the humidifier and a basic manual. The H20 is fairly small for a humidifier and its build is compact, with multiple layers stacking into one another. The base of this humidifier contains its heating element and removable essential oils compartment, with a steam stack that’s also removable. One “layer” up you have the product’s 5 litre water basin. Finally, this humidifier is topped with a two-part lid: The back half contains slats that you can fill the humidifier through, and the front half contains a steam nozzle.

This humidifier runs on a power cord that is non-removable.

What's in the box of the JS H20 cool mist humidifier

What’s the difference between a warm mist and cool mist humidifier?

Warm and cool mist humidifiers may seem similar, but they operate on different principles. Warm mist humidifiers (or “vaporizers”) boil water until it turns into steam. That means they’re generally better than cool mist humidifiers at reducing bacterial cultures and can make the air feel more comfortable in cold rooms.

Cool mist humidifiers use fan-based or ultrasonic technology to disperse water into the air without heating it. They’re more prone to bacterial overgrowth, so remember to clean them regularly. However, they’re significantly more energy-efficient than warm mist humidifiers, and because they produce cool mist rather than hot steam, they’re safer to use around kids and pets.

This device does both. You can set it to function on either warm or cool mist, and in my opinion, it performs excellently for both.

Features of the JS H20 humidifier

The JS H20 ultrasonic humidifier has a five-button control panel on the front of the device. First, you have your power button—pretty basic. Next is your steam level, shown pictorially. Following that is your humidity control, your timer function for auto-shutoff, and your cool and warm mist selection.

The H20 can be set at three different intensity levels, humidity increments of 5% starting at 40%, or an auto-shutoff timer of 1-12 hours. Its LED display cycles through reporting its intensity, current humidity level, and steam output setting. (On cold, it reports 20-21 degrees Celsius.) Like most small humidifiers, it’s best for small to medium spaces: JS recommends using it in rooms of up to 320 square feet, or 30 square metres.

There’s no set of controls for this humidifier’s essential oils compartment, but there doesn’t need to be! The oil tray is easy to fill and works well—very well, actually. I find that most humidifiers and diffusers use either an essential oil tray on the top of the device or a pop-out essential oil pad in the bottom, but this compartment is different. It’s slightly more cumbersome to fill as you have to remove the entire water basin to access it, but once filled, this setup seems to offer significantly greater scent dispersal than either of the other methods I’m used to. Plus, because the compartment comes out, it’s easy to clean. Essential oils become sticky and resinous as they evaporate, so the fact that this compartment is removable will make long-term maintenance much easier.

JS H20 cool mist humidifier controls

My experience with the JS H20 ultrasonic humidifier

I typically used the JS H20 as a cool mist humidifier, set by intensity rather than humidity or time. It’s extremely dry in Alberta and my home has very high ceilings, so I never really hit a level of “too much” humidity. When I let the JS H20 run on low in my bedroom all day long with the door ajar, it maintains a humidity level of about 45%—an extremely comfortable improvement from the 20% it sits at without a humidifier in the fall.

I’m quite happy at a humidity of 40%, but when I want to get it higher than that, I can still use the JS H20 to get my home there. On high with my bedroom door fully shut, it can take my bedroom above 50% humidity, which is quite humid—it’s recommended to keep your home at a maximum of about 40%. For a product that’s the height of a ruler (just over 30 cm), I think that’s excellent. With this humidifier turned on, my home feels comfortable, cozy, and smells great. I’ve been filling my essential oils compartment with an oil blend I make at home, and I love the way it makes my home smell fresh and cheery. (It’s a blend of peppermint, spearmint, cedar, bergamot, mandarin, and lime oils.)

I find this humidifier to be extremely quiet, both on its cool mist and warm mist functions. Its LED screen can’t be turned off, so it can be a bit bright for bedrooms, but that helps prevent anyone from bumping into it if it’s being kept on the floor. When empty, the JS H20 humidifier automatically turns off for safety.

JS H20 warm mist humidifier review

How to care for your humidifier

The water in Alberta is quite hard, so I recommend using this (and any cool mist humidifier) with distilled or softened water only. If you don’t have a water softener installed in your home, that means using jugs of distilled water to fill your humidifier. Unfortunately, water purifiers don’t remove calcium and magnesium ions from the water, which is what makes it “hard.”

The calcium in hard water is what causes that rocky buildup on the heating elements of warm mist humidifiers. (I recommend removing it with hot water and vinegar if you already have a device with buildup.) In cool mist and ultrasonic humidifiers, you won’t notice the calcium right away—it exits your humidifier with the water vapour instead of collecting on a heating element. Over time, however, you’ll start to notice buildup in your home: Gritty-feeling bedsheets, chalky walls, dusty mirrors, and the like. It’s a major pain to clean out of your home, which is why it’s easier to opt for distilled water right off the bat.

Why top-fill humidifiers are the way to go

When I was a kid, we had a warm mist humidifier that sat out in the hallway upstairs all winter. If any of us got sick, we’d fill up the humidifier’s oil tray with Vicks and move it into the bedroom.

Our old humidifier worked like a champ, but it was so noisy and outdated. We’d fill it every night by lifting out the water basin, taking it into the bathroom, flipping it over, unscrewing its gasket, and sliding it under the bathtub faucet.

Nowadays, I only buy humidifiers like this one: ones with a top-fill humidifier design. It’s so much easier to keep your humidifier running if you don’t have to carry a wet, dripping jug of water upside down around the house every time your water levels get low. Just pour directly into the H20 from a jug and you’re back to full.

JS H20 humidifier review

In conclusion

Overall, I’ve been extremely happy with this humidifier. Its ultrasonic scent dispersal has excellent throw, reaching far outside of my bedroom even though the door is mostly shut. It’s quiet and compact, and I love its clean, simple design. As both a warm and cool mist humidifier, I find that it works very efficiently to raise the humidity level of my home. Not to mention—for a product that works this well and looks this cute, the price is great!

Shop the JS H20 ultrasonic warm and cool mist humidifier online at Best Buy today.

Rae Chen
Rae covers everything from air fryers to speakers here on the Best Buy Blog. Their work can also be found at thenotice.net, where they've been writing about beauty & wellness since 2007.