Levoit OasisMist 1000S Review: Output, Water, Cleaning and How It Compares

The Levoit OasisMist 1000S is a quiet ultrasonic cool-mist tower for bedrooms and mid-size living rooms. Levoit rates it below 28 dB, its 10 L (2.6-gallon) tank runs up to 100 hours on low, and Auto mode holds a set humidity. It costs around $135 to $150. We’d buy it for a bedroom if you’re willing to use distilled or purified water and clean it every 3 days; for a big open plan or hard tap water, an evaporative unit is the better tool.

This review is research-based. We didn’t run the humidifier ourselves: every number below comes from Levoit’s product page and user manual, the rival makers’ pages and manuals, and EPA, CPSC and MedlinePlus guidance. Our research method explains how we work.

Levoit OasisMist 1000S specs at a glance

Spec	Levoit OasisMist 1000S	Source
Type	Ultrasonic, cool mist only	Levoit
Model number	LUH-M101S-WUS	Levoit manual
Max output	350 mL/h (about 2.2 gal/day)	Levoit manual
Tank	2.6 gal / 10 L	Levoit manual
Runtime	Up to 100 hours on low mist	Levoit manual
Effective range	300 to 600 sq ft (one page line says 215 to 430)	Levoit
Humidistat	Built-in sensor; Auto mode target 40% to 80% in 10% steps, default 60%	Levoit manual
Filter	No replacement filter; washable filter on the silicone tube inside the tank	Levoit manual
Noise	Below 28 dB	Levoit manual
Power	27.5 W rated	Levoit manual
Size and weight	8.4 x 10.0 x 28.7 in; 6.4 lb	Levoit manual
Smart features	VeSync app, Alexa and Google Assistant	Levoit manual
Warranty	2 years	Levoit manual

Levoit’s product page doesn’t state an output figure; the 350 mL/h comes from the manual’s spec table. As with every humidifier, the runtime claim depends on the room’s temperature and humidity, and the manual says so.

How much room can it humidify?

At its 350 mL/h maximum, running nonstop, the 1000S puts out about 2.2 gallons a day (350 x 24 ÷ 3,785). That’s modest for a 10 L tank: the tank is sized for long runtime, not for high output. At full mist, a full tank would last roughly 28 hours by our math; on low, Levoit says up to 100.

Levoit’s range of 300 to 600 sq ft is a maker claim, and one line on the product page gives 215 to 430 sq ft instead. A typical bedroom sits well inside either figure. A 600 sq ft living room is the top end, and a leaky room in cold, dry weather may need more water than 2.2 gallons a day.

To check your own space, our humidifier size calculator estimates gallons per day from floor area, ceiling height, temperature and airtightness. Enter 2.2 gallons per day as the humidifier’s output, or convert any other model’s mL per hour the same way (x 24 ÷ 3,785). For bigger spaces, see our picks for the best humidifier for large rooms.

Auto mode, Sleep Mode and the 60% default

Auto mode uses the built-in sensor to adjust the mist level. With the default 60% target, the manual’s table runs high mist below 50%, medium from 50% to 55%, low from 55% to 60%, and stops above 60%. Change the target and those thresholds shift with it. By default it stops at the target (“Automatic Stop”); if you switch that off in the app, it keeps misting on low.

The 60% default is the catch. EPA advises not humidifying above 50%, because higher humidity may encourage biological growth, and EPA and CPSC suggest 30% to 50% indoors. MedlinePlus suggests setting a humidifier to 40% to 50%. You can set 40% to 80% in 10% steps, so we’d choose 40% or 50% on day one. Our guide to ideal indoor humidity explains why the upper limit matters.

Tip: Press and hold the Auto button until the display flashes, then tap to cycle through targets. You can also set the target in the VeSync app.

Sleep Mode drops the mist to low and turns off the display lights. The display also dims after 3 seconds and can be switched off entirely. MedlinePlus suggests placing a humidifier several feet (about 2 meters) from the bed, and the manual says to aim the nozzle away from furniture and walls.

Water: distilled, purified or tap?

This is the main trade-off of any ultrasonic humidifier. Levoit recommends purified or distilled water and says tap water may leave a white dust of dried minerals on surfaces. EPA says ultrasonic and impeller units are very efficient at dispersing tap-water minerals and recommends bottled water labeled “distilled,” noting that minerals also promote scale, which can harbor microorganisms. Water labeled “spring” or “mineral” hasn’t been treated to remove minerals.

Distilled water is the simplest fix. Our guide on what kind of water to use in a humidifier compares the options and costs. If your tap water is hard and you’d rather not buy jugs, our Levoit Superior 6000S review covers an evaporative model that Levoit says works with tap water.

On the plus side, filling is easy. The 1000S fills from the top: remove the cover and pour room-temperature water into the water inlet tank with a pitcher, without lifting the tank off the base. Don’t use hot water, and don’t fill past the max line.

Cleaning and running cost

Levoit’s manual sets a strict routine:

• Change the water daily.
• Clean the water inlet tank, base chamber and water tank every 3 days and before storage.
• Never immerse the base, don’t use a dishwasher and don’t use detergents.
• To descale, pour 6 cups (1,420 mL) of distilled white vinegar into the tank and 1 cup (240 mL) into the base chamber, soak 15 to 20 minutes, scrub with the brush, soak the tube filter in vinegar for an hour, then rinse until the smell is gone.
• Add essential oils only to the aroma pad, never to the water, and don’t add water treatment liquids or third-party filters.

That lines up with EPA’s advice to empty, dry and refill portable humidifiers daily and clean them every third day. CPSC found that bacteria and fungi can grow in humidifier tanks and be released in the mist. Our step-by-step guide on how to clean a humidifier covers the routine in detail. If you plan to use the aroma pad, read essential oils in a humidifier first, especially with cats or other pets in the house.

Power is low. At its 27.5 W rating, running around the clock, it would use about 0.66 kWh a day, roughly 12 cents a day at the US average of 18.31 cents per kWh (EIA, July 2026), by our math. Distilled water will likely cost more than electricity.

OasisMist 1000S vs LV600HH, Dreo 735S and Superior 6000S

	OasisMist 1000S	Levoit LV600HH	Dreo HM735S	Superior 6000S
Type	Ultrasonic, cool	Ultrasonic, warm and cool	Ultrasonic, cool	Evaporative
Max output	350 mL/h	500 mL/h warm, 300 cool	Not published	1,500 mL/h
Tank	2.6 gal	1.5 gal	2.9 gal	6 gal
Range claim	300 to 600 sq ft	430 to 753 sq ft	Up to 700 sq ft	3,000 sq ft
Price	Around $135 to $150	Around $100	Around $140	Around $250

Levoit OasisMist 1000S

The 1000S is the one to pick for a bedroom when quiet operation, a long runtime and app control matter more than raw output. The trade-offs are the 60% default, the need for distilled or purified water and a cleaning routine every 3 days.

Check the Levoit OasisMist 1000S on Amazon

Levoit LV600HH

The LV600HH adds warm mist: up to 500 mL/h warm or 300 mL/h cool from a 1.5-gallon tank, with a 40% to 80% humidistat. It costs less, but the heater is rated at 280 W, Levoit publishes no dB figure, and the tank is smaller (up to 36 hours per fill). Warm mist can burn, and MedlinePlus advises cool mist, especially around children. Our comparison of warm mist vs cool mist humidifiers covers the trade-off.

Check the Levoit LV600HH on Amazon

Dreo HM735S

The Dreo 735S is the closest rival: an 11 L (2.9-gallon) ultrasonic tower that Dreo rates at 26 dB, with up to 100 hours of runtime and a 700 sq ft claim. Dreo doesn’t publish its mist output, so the bigger range claim can’t be checked against a number. Like the Levoit, it needs distilled or purified water to avoid white residue.

Check the Dreo HM735S on Amazon

For more quiet options, see our full list of the best humidifiers for bedrooms.

Who the OasisMist 1000S suits, and who should skip it

Good fit:

• Bedrooms and nurseries where a quiet, cool-mist unit and a dark display matter
• People who want to fill it once and leave it for a few nights on low
• Smart-home users who want app control, Auto mode and voice assistants

We’d skip it if:

• You’d rather use tap water; an evaporative unit won’t leave white dust
• Your room is well over 600 sq ft or open to the rest of the floor
• You won’t clean it every 3 days

Note: A humidifier can make dry air more comfortable, but a dirty one can make things worse. EPA says that if you have breathing symptoms you associate with humidifier use, stop using it and talk to your doctor.

Our verdict

On paper, the Levoit OasisMist 1000S is a strong bedroom humidifier: under 28 dB, a 10 L top-fill tank that runs up to 100 hours on low, 27.5 W of power, and Auto mode with app control. Its weak spots are a modest 350 mL/h maximum, a conflicting room-size claim, a 60% default target and the usual ultrasonic need for distilled water. In our view it’s one of the easiest ultrasonic towers to live with, provided you lower the target and keep up with cleaning.