Levoit OasisMist 450S Humidifier – Hands-on Review!

Full Review

The Levoit OasisMist 450S is a very popular humidifier and one of the best Levoit models I’ve had the opportunity to use so far.

This humidifier has a 4.5 L water tank, is designed for rooms up to 430 sq. ft. (40 m²), and delivered excellent results in our tests.

It also comes with plenty of advanced features and can operate as a cool mist and a warm mist humidifier.

It’s easy to clean and is definitely a humidifier worth considering, and it may be the ideal model for your space.

How We Tested the Levoit OasisMist 450S?

1. We test every humidifier in the same 194 sq. ft. (18 m²) room. Before each test, we use a dehumidifier to lower the relative humidity in the room to around 40% RH, so every unit starts the test under identical conditions.

2. To track humidity levels, we use the Govee Hygrometer H5075 as our primary measuring device. We also set up a ThermoPro hygrometer as a secondary unit, which we use to confirm and cross-check the readings from the Govee.

3. We turn the Levoit OasisMist 450S to maximum speed and let it run for 60 minutes. During this time, we measure the total RH increase the unit achieves, as well as how long it takes to raise the humidity by +5% RH.

4. We measure how much water the Levoit OasisMist 450S uses in 60 minutes of running at max speed. Based on the measured water consumption (in mL/h) and the tank capacity, we calculate the real runtime on a full tank, not the manufacturer’s claim, but what we actually measured in our test.

5. Finally, we measure the power consumption of the Levoit OasisMist 450S using a power meter. From this, we calculate how much it would add to your electricity bill if you ran it 24/7 at max speed for a month, and its efficiency in mL of water per watt-hour (mL/Wh), a metric that shows how well the unit converts electricity into moisture output.

We tested the performance of this humidifier using the Govee Hygrometer H5075 as our primary measuring instrument and a ThermoPro as a secondary device.

This was a precise test performed under controlled conditions, where we measured how quickly and efficiently the humidifier increased the humidity level in the room.

Efficiency Test

The room where we performed our tests is 194 sq. ft. (18 m²). One important thing to note is that before each test, we lower the humidity level to around 40% RH using a dehumidifier.

In this case, the starting humidity level was 40.3% RH. After 60 minutes of operation at maximum speed, the Levoit OasisMist 450S increased the humidity to 57.2% RH, which represents an impressive 41.94% increase.

Another important metric, as shown in the chart, is that the Levoit took just 11 minutes to increase the humidity by 5% RH.

We can say that the Levoit OasisMist 450S achieved one of the best results in this test. It increased the humidity by approximately +16.9% RH after 60 minutes of operation at maximum speed.

For comparison, the DREO HM311S increased the humidity by only +12% RH under similar conditions.

Overall, there is no doubt that the Levoit OasisMist 450S is one of the most effective humidifiers we’ve tested.

Runtime

However, efficiency and speed weren’t the only things we measured during the previous test.

We also measured how much water this humidifier would use during 60 minutes of operation.

The Levoit OasisMist 450S used 300 mL of water in 60 minutes at maximum speed while increasing the humidity by +16.9% RH.

This means that with a full tank, the humidifier can run continuously for about 14.9 hours at maximum speed. That’s a solid result, but not particularly groundbreaking, especially considering its large 4.5 L water tank.

For comparison, the Levoit Classic 300S has similar hourly water consumption at maximum speed, but its tank lasts for around 20.9 hours. Keep in mind, though, that this model has a larger 6 L water tank.

Overall, I would say that the runtime of the Levoit OasisMist 450S is very good, especially since the device is unlikely to operate at maximum speed all the time.

I would also recommend being cautious with the marketing claim that this model can run for up to 45 hours on a single tank. That may be accurate, but most likely only when the humidifier is running at its lowest speed.

When it comes to operating costs, we’re primarily looking at electricity consumption, along with some additional expenses, such as aroma pads in the case of this Levoit.

What’s interesting is that even though the Levoit OasisMist 450S uses a 280W motor, it isn’t necessarily a huge power consumer.

Why? Because it only uses that much power when the warm mist feature is turned on, which is not something most people will use all the time, perhaps mainly during winter.

At maximum speed (speed 9), the Levoit OasisMist 450S consumes just 27.4W. That’s a reasonable level of power consumption and far lower than the previously mentioned 280W.

However, it’s worth keeping in mind that when warm mist is enabled at maximum speed, this model consumes 279.4W.

For example, if you used the Levoit OasisMist 450S at maximum speed 24 hours a day for an entire month, your electricity bill would increase by around $2.40. Under the same conditions but at the lowest speed, the increase would be around $1.84.

If you look at the chart above, you’ll see that the Levoit OasisMist 450S may not be the best-optimized model in terms of power consumption compared with some of the other humidifiers we tested. Still, I don’t think its electricity use is excessive or that it represents a significant monthly or yearly expense.

I also included a chart showing how many milliliters of water each humidifier outputs per watt-hour. Interestingly, the Levoit OasisMist 450S performs much better in this metric. It outputs 11.0 mL/Wh, while some other models with more power-efficient motors have significantly lower output capacity.

Overall, I’d say the Levoit OasisMist 450S is a reasonably well-optimized humidifier.

Cleaning & Maintenance

When it comes to cleaning the device, this is one area where Levoit could have done a little better.

Although everything comes apart easily and each component can be cleaned separately, the overall process can be somewhat time-consuming and may take longer than just a few minutes, which is all some other humidifiers require.

In addition, it’s generally not recommended to put the parts of this model in the dishwasher.

Another factor that can make cleaning more difficult is the use of tap water. If you use tap water, mineral buildup is more likely to form inside the device, and this can be much harder to remove than when using distilled water.

Overall, cleaning isn’t complicated, but you should expect to spend around 10–15 minutes actively cleaning the humidifier.

Features Overview

The Levoit OasisMist 450S comes with plenty of advanced features. It’s a smart humidifier with an auto mode, smart app support, and several other useful features.

It’s refreshing to see a humidifier that is both highly effective and easy to use at the same time.

Humidity Sensor & Auto Mode

The built-in sensor monitors the relative humidity in the room and displays the current reading either on the device itself or in the app. This data is also used to automatically adjust the humidifier’s operation.

This means that when the humidifier is set to Auto Mode, it automatically adjusts the speed and operating mode based on the current RH level in the room.

Another thing I really like is the detailed RH data available in the app, as well as the accuracy of the built-in sensor. It proved to be quite precise, especially when compared with the sensors we use for testing. I didn’t notice any significant discrepancies.

Sleep Mode

Sleep Mode is designed for nighttime use. In this mode, the display turns off, the device operates more quietly, and it uses a lower mist output to minimize sleep disruption.

It also has a pretty catchy night-light feature, which could be a great addition if you want some ambient light in your bedroom or any other place.

Demineralization Cartridge

The demineralization cartridge helps reduce the amount of minerals in the water that can be released into the air as white dust by ultrasonic humidifiers.

It can also help slow down mineral buildup inside the device, which is especially useful if you use hard tap water. The cartridge is a consumable part and needs to be replaced periodically.

Warm & Cool Mist

The device can produce both cool and warm mist. Cool mist is more energy-efficient and suitable for everyday use, while warm mist provides stronger humidification and can feel more comfortable during colder months.

Aroma Box

The OasisMist 450S has a dedicated aroma box with a pad where you can add a few drops of essential oil. The oil should not be added directly to the water tank.

Although this feature isn’t as effective or as refined as using a dedicated essential oil diffuser, it’s still a nice extra that many users may appreciate.

Design & Build Quality

When it comes to design, there isn’t much to criticize. The overall build quality is excellent, and the plastic feels high-quality and durable.

For this type of product, I don’t think much more is really needed.

The control panel is located on the front, with the buttons and status indicators, while the water tank is positioned behind it.

One thing I particularly like is that the water tank has a handle, making it easy to carry to the bathroom or kitchen faucet if you prefer to refill it that way.

The OasisMist 450S uses a practical top-fill design, which means you can pour water directly from the top without having to flip or awkwardly handle the tank. The 4.5 L capacity also allows for long periods of operation between refills.

What I do miss on this model, from a design standpoint, is built-in handles or side grips for easier carrying. Some competing models handle this very well, such as the DREO HM311S.

Other than that, this humidifier is very well designed, and I don’t have any major complaints.

What comes with the device?

When you purchase the Levoit OasisMist 450S, the package includes 1x humidifier, 1x cleaning brush, 3x aroma pads, 3x adsorption pads, 2x water sponges, a user manual, and a quick start guide.

FAQ on Levoit OasisMist 450S