Not all humidifiers are good for a large room. Home humidifiers have quite a range; you can find anything from the cute 300 ml units to the big 10+ L Lacidoll humidifiers. We have tallied up all the best large humidifiers that adequately humidify large rooms (with 500+ sq ft coverage).

Using a large room humidifier has quite a few benefits. Here’s just one very interesting suggestion from the National Institute On Aging:
“Try using a humidifier, an appliance that adds moisture to a room.” (US Department of Health & Human Services, NIH NIA, Chapter ‘Dry Skin and Itching’)
If you have a large room and you would like to increase moisture it in, it makes sense to get the best humidifier for large rooms, right?

There are quite a few distinctions that separate the good large room humidifiers from the best humidifiers from large rooms, apart from the specified room coverage area.
We are going to cover all of the important specs you should be aware of. Based on these, we have created a list of the best large room humidifiers, complete with a spec-by-spec comparison.
You will find all of this further on. First, we’re going to cover 4 primary and 4 secondary specifications you need to be aware of when buying a large room humidifier. If you want just to know which humidifiers are best for large rooms, you can skip to the list, comparison table, and reviews here:
Skip To List Of 5 Best Large Room Humidifiers
Let’s first look at which exact specifications you should be looking at to pinpoint the top-rated large room humidifiers:
4 Key Specifications To Check In Large Room Humidifiers
The primary specs to check for if you are in a market for a big room air humidifier are:
- Water capacity. Large room humidifiers should have large water tanks; at least 3L. In the table below, you will find humidifiers with as much as 6 L water capacity (Note: The best whole house humidifiers don’t have a tank, it has a continuous supply of water).
Large room humidifiers also have built-in humidistats with humidity indicators (set humidity levels to let’s say 40% and check with indicator). - Room coverage. This goes without saying; manufacturers specify how big a room can their humidifier adequately humidity. The biggest humidifiers can adequately humidifier areas from 323 sq ft to 753 sq ft; the whole house HVAC humidifier has an extremely large 4,000 sq ft coverage area).
- Warm and cold mist output. Most humidifiers are cold mist-only humidifiers; the best large room humidifiers like #1 TaoTronics TT-AH046 can produce both cold and warm mist with 200+ ml/h output.
- Running hours. Refueling the water tank is a bother; the best humidifiers for large spaces should be able to run for 40+ hours without refueling.
4 Secondary Specs To Check As Well
Secondary specs include:
- How easy it is to clean a humidifier. Cleaning is another bothersome task with large humidifiers; it makes sense to pick the easiest to clean a large room humidifier. #2 Levoit LV600HH is a good example of a very easy to clean humidifier for large rooms.
- Noise levels. If you are looking for a humidifier for a large bedroom, you should look at the decibel levels. Whisper quiet humidifiers are obviously preferred. The quietest large bedroom humidifier is the #3 Taotronics TT-AH045; it generates as little as 26 dB of noise.
- Type of humidifier. Cold mist humidifiers are the most popular (Check #1, #2, #3 units). Types of humidifiers range from the best whole-home humidifiers that are built into the HVAC ductwork (Example: #4 Aprilaire 400M with up to 4,000 sq ft coverage) to the best filterless ultrasonic humidifiers for large rooms (Example: #5 Everlasting Comfort humidifier).
This is how a whole-home humidifier looks like when installed into existing HVAC ducting. - Inclusion of a built-in humidistat. Humidistat tells you what is the relative humidity in your house. Your target relative humidity should be 35% – 45%. According to Condair and based on the “Criteria for Human Exposure to Humidity in Occupied Buildings” article, “…humidity of 35% – 45% is shown to reduce the incidence of respiratory infections and allergies and asthma symptoms by minimizing the formation of bacteria, viruses, fungi, and dust mites.”
What Size Humidifier Do I Need For A Large Room?
Humidifier sizing is an underrated aspect here. In many cases, we don’t have to worry about how big a humidifier we need. However, if we have a large room, we do need to know what size humidifier will adequately moisture such a bigger room.
The ability of a humidifier to increase relative humidity levels from 20-30% (too low) to 35-45% (just perfect) is correlated with the warm or cold mist output. However, that specification – the cold mist output – is missing from the specification sheet of most humidifiers.
That’s why the simplest way to size a humidifier is to correlate water capacity (tank size) with room coverage. We can use this rule of thumb in the standard 8ft ceiling rooms:
1L of water capacity = 100 sq ft coverage
Water capacity is measured in liters (L). 1L is equal to about 1/4 of a gallon. For every 1 L of water tank capacity, such a humidifier can cover roughly 100 sq ft of living area.
That means that 1L humidifiers are good for a small 100 sq ft room and the big 6L humidifiers are good for large rooms.
Based on this humidifier sizing rule of thumb, you can roughly estimate the size of the humidifier you need. To help you out, we calculated a few examples in this table:
Room Size (in Sq Ft): | Example Of Such Room: | Humidifier Size (in L) |
100 sq ft | 10×10, 10×12, 12×12 rooms | 1L humidifier |
200 sq ft | 14×14, 14×16, 16×16 rooms | 2L humidifier |
300 sq ft | 16×18, 18×18 rooms | 3L humidifier |
400 sq ft | 18×20, 20×20, 21×21 rooms | 4L humidifier |
500 sq ft | 22×22, 22×24 rooms | 5L humidifier |
600 sq ft | 24×24, 26×26 rooms | 6L humidifier |
800 sq ft | 26×28, 28×28 rooms | 8L humidifier |
1,600 sq ft | 40×40, 38×42 rooms | 16L humidifier |
With all this in mind, let’s have a look at which are the best large space humidifiers for sale currently on the market:
Best Humidifiers For Large Rooms
- Biggest Residential Humidifier For Largest Rooms (16L): Lacidoll 16L Humidifier
- Quietest Humidifier For A Large Bedroom (8L): Lacidoll 8L Humidifier
- Best Easy To Clean Large Room Humidifier (6L): Levoit LV600HH
- Best Extra Large Whole-Home Humidifier: Aprilaire 400M (Up to 4,000 sq ft homes)
- Best Filterless Ultrasonic Humidifier For A Big Room (6L): Everlasting Comfort
Large Room Humidifier: | #1 Lacidoll 16L | #2 Lacidoll 8L | #3 Levoit LV600HH | #4 Aprilaire 400M | #5 Everlasting Comfort |
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Water Capacity: | 16L / 4.2 Gallons | 8L / 2.1 Gallons | 6L / 1.59 Gallons | 17 Gallons/Day | 6L / 1.59 Gallons |
Room Coverage: | Up to 1,000 sq ft | Up to 500 sq ft | Up to 753 sq ft | Up to 4,000 sq ft | Up to 500 sq ft |
Cold Mist Output: | 1,000 ml/h | 300 ml/h | N/A | N/A | N/A |
Running Hours: | Up to 48 hours | Up to 36 hours | Up to 60 hours | Continous | Up to 50 hours |
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Price: | $$$$ | $$$$ | $$$$ | $$$$ | $$$$ |
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Availability: | Check Price | Check Price | Check Price | Check Price | Check Price |
1. Biggest Residential Humidifier For Largest Rooms: Lacidoll 16L Humidifier

Water Capacity: | 16L / 4.2 Gallons |
Room Coverage: | Up to 1,000 sq ft |
Running Hours: | Up to 48 hours |
Warm Mist Output: | N/A |
Cold Mist Output: | 1,000 ml/h |
Built-In Thermostat? | ![]() |
Dimensions (HxWxD): | 27.4 x 11.7 x 11.09 inches |
Weight: | 9.63 lbs |
Price: | $$$$ |
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Lacidoll 16L humidifier is by far the biggest humidifier for the largest rooms. It’s quite an outstanding unit; it has a 1,000 ml/h cold mist output, built-in humidifiers, a huge 16L tank and it’s remarkably easy to clean due to smooth surfaces. It has an up to 1,000 sq ft specified coverage area; more than enough even for the biggest 30×30 rooms (of course, you can put in a smaller room as well).
The 16L or 4.2-gallon water tank is essential for it to be able to service large rooms. With such a large and fast-working humidifier, the built-in humidistat is essential. You can set it to 40% and up to 90%; the Lacidoll 16L humidifier will produce a considerable water moisture output until the set humidity is reached in a large room.
What is more, the smooth surfaces make it very easy to clean.
With 1 full water tank, you can run it uninterrupted for up to 48 hours.
The only downside is that if you put it in a room below 300 sq ft, it’s kind of overkill. The Lacidoll 16L is specifically designed to be used in large rooms and provides a fast increase in humidity.
All in all, Lacidoll 16L is a versatile powerhouse. With 16L capacity, it has a 1,000 sq ft coverage area, and will adequately increase humidity levels in any large room:
2. Quietest Humidifier For A Large Bedroom: Lacidoll 8L Humidifier

Water Capacity: | 8L / 2.1 Gallons |
Room Coverage: | Up to 500 sq ft |
Running Hours: | Up to 36 hours |
Warm Mist Output: | N/A |
Cold Mist Output: | 300 ml/h |
Built-In Thermostat? | ![]() |
Dimensions (HxWxD): | 29.75 x 10.75 x 10.5 inches |
Weight: | 5.5 lbs |
Price: | $$$$ |
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Lacidoll 8L is a great example of a big humidifier. It has an 8L water capacity and is perfectly sized for large bedrooms. The key advantage of Lacidoll 8L is the 35 dB noise levels; it’s super silent. That’s why this is the best humidifier for large bedrooms.
In a bedroom, the noise levels (decibels) are essential. If you can’t sleep with a humidifier turned on (due to noise), you will probably wake up with below 30% relative humidity levels (and associated problems) on winter nights.
To combat noise levels, the Lacidoll 8L comes with a water dripping system that turns it into a whisper-quiet humidifier, perfect for large rooms. In fact, while running, it generates as little as 35 dB. That is quieter than any other humidifier with above 300 sq ft coverage area.
With the 8L tank capacity, the Lacidoll 8L can run for about 36 hours. It has a specified coverage area of up to 500 sq ft. The average bedroom size is 132 sq; a master bedroom is a minimum of 224 sq ft (14×16). With up to 500 sq ft, the Lacidoll 8L will adequately increase the relative humidity even in bigger master bedrooms.
All in all, the key part for increasing humidity levels in master bedrooms is a big yet quiet humidifier. Lacidoll 8L is one of the biggest and definitely the quietest large humidifiers, perfect for master bedrooms:
3. Best Easy To Clean Large Room Humidifier: Levoit LV600HH

Water Capacity: | 6L / 1.59 Gallons |
Room Coverage: | Up to 753 sq ft |
Running Hours: | Up to 60 hours |
Warm Mist Output: | 500 ml/h |
Cold Mist Output: | N/A |
Built-In Thermostat? | ![]() |
Dimensions (HxWxD): | 11.6 x 7.7 x 11.3 inches |
Weight: | 5.3 lbs |
Price: | $$$$ |
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Levoit is one of the top price-performance brands for humidifiers. Their biggest model – the big room 6L – is the Levoit LV600HH. The key to all Levoit models is that they are designed as easy-clean humidifiers. The Levoit LV600HH is the best easy to clean humidifier for large rooms currently on the market.
Similar to the #1 Taotronics unit, the Levoit LV600HH has a 6L water capacity and 753 sq ft coverage area. That’s enough for the biggest rooms.
With its 280W electrical power input, it can generate up to 500 ml/h of mist output (both cold and warm mist). You can even add essential oils in the mix if you want to have some aroma alongside the increase in indoor humidity levels.
The smooth surfaces are essential for easy cleaning. Humidifiers can be notoriously difficult to clean; all the nooks and crannies have to be scrubbed from time to time in order to avoid mold and algae growth. Levoit LV600HH makes this task simple. You can reach every internal part easily even if you have large hands. The outside surfaces are smooth and can be cleaned as easily as you clean your TV, for example.
In short, the Levoit LV600HH is the best easy clean humidifier for large rooms. It has up to 753 sq ft coverage area, can generate up to 500 ml/h cold or warm mist output, and it’s the easiest large room humidifier to clean:
4. Best Extra Large Whole Home Humidifier: Aprilaire 400M (Up to 4,000 sq ft homes)

Water Capacity: | 17 Gallons/Day |
Room Coverage: | Up to 4,000 sq ft |
Running Hours: | Continous |
Warm Mist Output: | N/A |
Cold Mist Output: | N/A |
Built-In Thermostat? | ![]() |
Dimensions (HxWxD): | 15.4 x 15.8 x 10.3 inches |
Weight: | N/A |
Price: | $$$$ |
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Aprilaire 400M is in another category of large humidifiers entirely. This is a whole-home humidifier; the kind that is usually installed into the HVAC ducting and supplies not only 1 big room but your entire home with additional moisture. Aprilaire is generally considered as the best brand for the whole-house humidifiers and the Aprilaire 400M is their most popular model.
Whole-home humidifiers don’t have a water tank. They have a continuous flow of water. The biggest the whole-home humidifier, the biggest continuous flow it will have. Aprilaire 400M has a 17 gallons per day water flow. This is used to generate enough moisture to raise humidity levels in houses with up to 4,000 sq ft (net total).
The problem with the whole-house humidifiers like Aprilaire 400M is that:
- Requires installation that is more complex than that of a standard plug-it-in humidifier.
- Requires ductwork.
- Costs more. The standard price for a whole-house humidifier is $200+.
On the upside, if you install a whole-home humidifier, you don’t really need a humidifier in every room. It’s the most cost-effective way to elevate the relative humidity levels in an entire house. You don’t have to room by room. Aprilaire 400M has a 4,000 sq ft coverage area; to match that, you would need 5-8 large room humidifiers.
All in all, if you’re looking for a whole-home humidifier, the Aprilaire 400M is your best option:
5. Best Filterless Ultrasonic Humidifier For A Big Room: Everlasting Comfort

Water Capacity: | 6L / 1.59 Gallons |
Room Coverage: | Up to 500 sq ft |
Running Hours: | Up to 50 hours |
Warm Mist Output: | No Warm Mist |
Cold Mist Output: | N/A |
Built-In Thermostat? | ![]() |
Dimensions (HxWxD): | 11 x 7 x 13 inches |
Weight: | 3.1 lbs |
Price: | $$$$ |
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Everlasting Comfort humidifier is both big and appropriate to be used in bigger rooms. Its main advantage is that this is a humidifier without filters. With up to 500 sq ft coverage, the Everlasting Comfort is the best filterless humidifier for large rooms.
This ultrasonic humidifier is quite a neat unit. Nobody really likes maintaining, cleaning, and changing humidifier filters. The ultrasonic water evaporation mechanism of Everlasting Comfort humidifiers enables it to operate without filters. That saves you quite a lot of filter cleaning time and associated costs.
It is still a 6L unit but it has a lower specified coverage area than other big 6L humidifiers; 500 sq ft, to be exact.
You can also use essential oils (you get a special tray for that) to add aroma.
However, the biggest con of the Everlasting Comfort unit is the reliability. This is a no-name brand and not exactly well-known in the HVAC world. They do have a 2 year replacement policy which is a plus:
Here you have it, these are the basics of how to pick the best humidifier suitable for a large room. If you have any questions or suggestions, you can pose them in the comments below and we’ll try our best to help you out.
Your room-sizing does not take into account the cubic volume of the room. I have a 16×20 room (room size 320 by your calculations). However, the ceiling is 14 ft high. Does this mean I have to humidify 4000 cubic feet of space?
Hello Art, you’re correct, we presume the standard ceiling height of 8 ft. In your example, you have a 14 ft ceiling instead of an 8 ft ceiling; that means you have the ‘1 L = 100 sq ft’ doesn’t really apply. The more appropriate humidifier sizing for a high 14 ft ceiling would be ‘1 L = 60 sq ft’. Hope this helps.
I usually choose products based on the features I want, and the everlasting comfort humidifier was the most outstanding. Luckily, it has no filters and is easy to clean.