A safer alternative to candles—a diffuser is an affordable and simple way to distribute a pleasant therapeutic scent throughout your home or workplace to help you feel relaxed and rejuvenated. With just a few drops of essential oils, you can fill an entire room with a soothing, energizing, or healing aroma.
However, if you want to diffuse essential oils in a large space, it’s important to buy a powerful diffuser with a big tank capacity that’s designed to cover large rooms.
Smaller models can struggle to spread the fragrance across all corners of a room, and you may not get the full aromatherapy benefits.
We’ve reviewed and rated the best diffusers for large rooms to help you find the perfect model to freshen up your workspace or create a tranquil retreat in your own home.
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Best Essential Oil Diffuser for Large Space Reviews
1. Best Overall: ArOmis Nebulizing Essential Oil Diffuser
If you want a diffuser that does the best possible job at dispersing a scent throughout your home, and if you don’t mind paying a little extra for a professional-grade model, then you need the ArOmis diffuser.
This essential oil diffuser is a nebulizer, unlike our other picks, which are all ultrasonic models. It operates without any water to diffuse concentrated essential oils in their purest form—without heat or dilution. The diffuser works by forcing compressed air into a glass tube, creating an intense mist filled with aroma.
The ArOmis nebulizer will fill a large room with essential oils significantly quicker than any other diffuser in this list. That’s why it’s our top recommendation for a large space.
It will quickly cover a large area up to 900 square feet, and you can adjust the dial on the base to any intensity you desire. The ArOmis disperses essential oils intermittently on a built-in 10 minutes on, 10 minutes off function, and it will automatically shut off after 4 hours. The natural beech wood base and hand-blown glass tube also make it an attractive option for a gift.
The ArOmis is the best essential oil diffuser for large rooms. It’s powerful, easy to use, and compared to other nebulizers, it’s less expensive and far quieter. The ArOmis has all the features you need to scent a large area with a relaxing aroma to help you unwind at the end of a long day.
2. Runner Up: Exqline 1500ml Large Essential Oil Diffuser
Specially created for very large spaces, the Exqline essential oil diffuser has a 1500ml water tank capacity with a runtime of up to 20 hours. This high-quality cool mist ultrasonic diffuser also doubles as a humidifier.
It’s rated to humidify the air in rooms up to 325 square feet, and it will provide aromatherapy scent coverage up to 450 square feet. Even though it’s powerful enough to cover large areas, it’s still whisper-quiet, producing just 35dB of noise. You’ll be able to have a peaceful night’s sleep if you want to use it in your bedroom.
Rather than a basic high and low setting, this model features a fully adjustable mist level that can be easily increased or decreased with the dial’s turn. You can also adjust the light—if it’s too bright for your liking, you can dim it down or turn it off completely.
The Exqline diffuser is also BPA-free and has a safety auto-shutoff function when the unit runs out of water. While we rate this model very highly for its large capacity tank and quiet operation, unfortunately, it does not have a timer function.
3. Best Budget Option: URPOWER 1000ml Large Essential Oil Diffuser
The best-selling URPOWER 1000ml essential oil diffuser is strong enough to handle larger living rooms with a coverage area of 430 square feet, and the 1-liter tank capacity gives it the ability to run all night while you sleep. It can run for 10 to 15 hours on high-mist mode or 15 to 20 hours on low-mist mode without the need to refill the unit.
This powerful but whisper-quiet model can not only diffuse essential oils, but it also operates as a humidifier and night light to help you transform your home into a peaceful and stress-relieving environment.
The budget-friendly diffuser features a color-changing LED light with seven different colors to choose from. A timer can be set to run the unit for 3, 6, or 9 hours giving you plenty of time to fill a large space with your desired aroma. A waterless auto-shutoff feature is also included for added safety, which means you can let the unit humidify and scent your space without having to worry if it runs dry. For added convenience, the diffuser can be operated by a handy remote control so you can relax in bed or on the sofa while you control it.
4. Best Smart Diffuser: Sierra Modern Home 400ml Smart WiFi Diffuser
The Sierra Modern Home 400ml essential oil diffuser is a WiFi-connected smart model that can be operated manually just like any other diffuser, or you can use the companion app to control it. With the smartphone app, you can control timer settings, scheduling, mist intensity, and LED color. The device is also compatible with Alexa and Google Home so that you can control it with your voice.
One of our favorite features of this smart diffuser is the ability to schedule when you want the diffuser to turn on and off. You can have the diffuser turn on just before you arrive home after a long day at work so you can walk straight into a relaxing environment.
The diffuser has a tank capacity of 400ml and can run for up to 12 hours continuously. This ultrasonic model can also emit enough water vapor to be able to humidify a large space.
The Sierra Modern Home diffuser has a modern and structural silhouette making it look more like an interior décor feature than a machine. If you want an internet-connected diffuser that you can operate from your smartphone, then this is the model to buy.
The URPOWER 500ml essential oil diffuser is an affordable option that still offers many premium features and the ability to cover 430 square feet.
The mist settings on the URPOWER 500ml diffuser allow you to set a timer for 60 minutes, 120 minutes, or 180 minutes. Alternatively, because it has a half-liter water tank capacity, this large diffuser can run for up to 10 hours non-stop, and the unit will automatically shut-off when it runs out of water. You can also set the mist level to high or low. A low setting will allow the device to run for a more extended period before it requires refilling. The high mist mode will spread your essential oils to a greater distance, and it can also humidify the air in your room if it’s too dry.
This large ultrasonic diffuser has an independent LED light that can operate even when the diffuser is not dispelling water vapor. The light has seven colors to choose from, and you can adjust the brightness. You can also set the light color to change automatically, or you can select your preferred color.
The smaller 500ml water capacity might not be practical for some users, as you will need to fill the water tank more often than our top picks, and you don’t get a remote control. But if you’re on a tight budget, this diffuser is an excellent option for those looking to get into aromatherapy for the first time.
This large essential oil diffuser has a massive 2200ml tank, making it roughly ten times bigger in capacity than a standard aromatherapy diffuser. The large capacity tank allows it to scent and humidify a room for up to 40 hours without stopping. If you need to cover a vast space and don’t want to be constantly filling up the tank, then the BlueHills XL is a great diffuser for large space.
The diffuser has a unique white wood grain finish with a color adjustable LED light. You can control the mist intensity with the turn of a dial, and the unit is equipped with an auto shut-off feature to protect it from overheating if the water runs out.
Unfortunately, this model does not have a timer function. You will have to let it run until you decide to turn it off or until the 2200ml tank runs dry, which may not be a bad thing if you need to freshen up a large room in your home.
The BZseed 550ml diffuser is a stylish and powerful model that can easily cover large bedrooms. It is ideal for humidifying the dry winter air while also freshening it up with your favorite essential oil mix. The 550ml tank capacity gives it a run time of up to 12 hours on low mist mode and 10 hours on the high setting.
The timer on the BZseed 500ml diffuser can be set to switch the unit off after 1, 3, or 6 hours. Otherwise, if you let it run continuously, it will automatically switch off when the water runs out, so you don’t have to worry about it if you leave it running overnight.
The ultrasonic technology also ensures the machine runs almost silently—it only generates a small amount of white noise to guarantee you are undisturbed whether you are sleeping or working. You can also turn off the color-changing ring while you sleep. Just make sure you place this diffuser in an easily accessible spot, as it does not come with a remote control.
The OminiHome 500ml large diffuser has a unique and elegant bronze exterior that will make it a feature piece in any home. The decorative metal lampshade exterior makes this unit look more like a cultural art piece than a cheap diffuser.
The aromatherapy essential oil diffuser can take up to 500ml of water and will output approximately 30ml per hour so you can safely allow it to run and fill your home with essential oil fragrances for up to 20 hours. As an additional safety feature, the unit will shut off automatically when the water runs out. The device has two modes, continuous and intermittent misting (30 seconds on/30 seconds off). Unfortunately, you cannot set a timer or adjust the intensity of the cool mist.
Also included is an LED light with seven color options, and combined with the stylish metal exterior, it’s an attractive device that will complement the style of any room. Thanks to ultrasonic technology, it operates at less than 35 decibels. So, whether you put it on show in your larger common areas or keep it for your private use in your bedroom, it won’t cause any noise disturbance.
Factors to Consider When Buying a Large Essential Oil Diffuser
Type of Diffuser
There are two types of essential oil diffusers—ultrasonics and nebulizers. Ultrasonic diffusers work by using a vibrating diaphragm to turn a solution of water and essential oils into a fine, cool mist. They tend to have a more subtle fragrance (because of the dilution of the essential oils) and they can also humidify the air. Ultrasonic models are more popular than nebulizers as they are considerably cheaper, and they usually operate more quietly.
Nebulizer diffusers emit pure essential oils into the air without any water. Instead, they employ compressed air to create a mist, which means they expel a much more concentrated fragrance of essential oils that will spread at a significantly faster rate. Nebulizers tend to be more expensive than ultrasonic models, and they can be tedious to clean due to their fragile glass components.
If you do not want to refill your ultrasonic essential oil diffuser more than once or twice a day, opt for a model with a large capacity tank. However, if you prefer an inconspicuous and cheaper unit that takes up less space, you may decide that having to refill multiple times a day is not such a big deal. The best diffusers for large rooms will have a tank capacity of at least 500ml.
Make sure the diffuser is rated to cover the area you’re trying to scent. For a small room, most standard aromatherapy diffusers can do the job. For a spacious living room with high ceilings, be sure to check the specifications to ensure your diffuser can reach all corners of the room.
Run Time and Timers
The run time of a diffuser will depend on the tank capacity and mist intensity settings. If you are looking to scent a large bedroom or a living room, you may find that the diffuser will need to run for a long time to spread your essential oil aroma effectively. A longer runtime will allow you to turn the diffuser on and let it do its job without having to worry about it. Some large diffusers also come with timers so you can schedule your diffuser to turn off after a few hours automatically, so you don’t overdo it and to save you from refilling the tank before the next use.
Remote Control and Smartphone App
Smartphone apps and remote controls allow you the flexibility of controlling your diffuser from the comfort of your bed or sofa. If your diffuser includes a mobile app, you can operate the unit and change settings from anywhere, and it will allow you to turn the unit on remotely so you can freshen up your home before you return after a stressful workday.
An automatic waterless shut-off on a diffuser is an important safety feature. It ensures that if you are away from your diffuser or are asleep when the water runs out, the machine will automatically turn off. It reduces the risk of the motor overheating and causing any damage.
Adjustable mist levels are not only essential to control the strength of the aroma, but it can also be useful to control the level of humidity in your room. Some models will have a basic high and low mist setting, and others will have a dial where the mist intensity is fully adjustable.
Quieter essential oil diffusers will ensure the unit remains unobtrusive to your lifestyle. Opting for a machine that has more subdued noise levels means you can use the diffuser in any part of the house, and it will not disturb you whether you are trying to have a sleep or you are holding an important meeting.
The best essential oil diffusers come with colored lighting options to help you customize your personal retreat’s ambiance and to act as a night light. Make sure that the light can be dimmed down or turned off completely, as it may bother you when you’re sleeping.
Cleaning Your Diffuser
It is vital to regularly clean your aromatherapy essential oil diffuser so that bacteria and mold cannot grow in the tank and to ensure that oil residue does not build up. Even when you switch between essential oils, wipe the tank down with a damp and clean cloth.
You can clean your ultrasonic diffuser using a small amount of fragrance-free soap. Alternatively, you could try adding a few drops of white vinegar and running your diffuser in a well-ventilated space for a few minutes.
It would be best if you cleaned nebulizer essential oil diffusers with rubbing alcohol once a week. If you are changing essential oils, you should clean it after every use. It is also worthwhile periodically soaking your nebulizer in dish detergent to keep it pristine.
Remember to read the product manual of the diffuser you choose to buy. It will include the best instructions on how to clean the unit effectively.
Lastly, there is a possibility of an ultrasonic essential oil diffuser producing white dust if you use tap water in the tank. White dust occurs when minerals from the tap water get sent into the air with the mist. If you have problems with white dust, try using distilled water in the tank instead.
Frequently Asked Questions
Q: What Size Diffuser Do I Need for a Large Room?
A: The bigger your diffuser’s tank capacity, the longer it can run, and the more space it will cover. Typically, the power of the diffuser will also increase relative to the tank size. A model with a tank capacity of 1-liter should be enough to cover the largest rooms in any home.
Q: Where Is the Best Place to Put My Diffuser?
A: Place your essential oil diffuser on a table or nightstand at least 2 feet above the ground and 1-foot away from walls and curtains. Ideally, it would work best if you positioned it in the center of the room. If you are using it in your bedroom, keep it at least 3 feet away from your bed. Choose flat surfaces and avoid placing it on or near any heat sources such as a furnace, heater, or direct sunlight.
Elevating your diffuser will not only avoid the mist puddling on the floor, but it will allow the aroma to reach higher into the air to be distributed better around your room.
Q: Do Diffusers Humidify the Room?
A: Yes, a powerful and sizeable ultrasonic diffuser can add humidity to a room, but it will not be as effective as a dedicated humidifier. A diffuser’s primary purpose is to disperse essential oils while a humidifier will add humidity to the air as fast as possible. Our top-rated diffuser on high mist mode will disperse 1-liter of water over approximately 12 hours. In contrast, the best humidifier for a large room can emit 6-liters of moisture over the same 12-hour period on high mist mode.
If you need to increase your home’s humidity level, it’s best to opt for a humidifier rather than a diffuser.
Q: What Is the Best Brand of Essential Oil?
A: Not all essential oils are manufactured to the same standards—every brand is different. When sourcing your essential oils, opt for brands that do not use any chemical fillers, only pure plant bases. Read user reviews to assess their quality, and it can also be useful to check the company’s website for third-party test results.
We recommend Plant Therapy essential oils. Every bottle of oil from Plant Therapy is subject to organoleptic testing by aromatherapy expert Robert Tisserand. They also go through multiple rounds of GC-MS testing by several third-party laboratories.
Q: How Many Drops of Essential Oil Do You Put in a Diffuser?
A: Most manufacturers recommend placing 3 to 5 drops of essential oil per 100ml of water in your diffuser tank. However, check your specific product’s manual or packaging for instructions.
An essential oil diffuser can fill your room with a refreshing and moisturizing aroma that will not only make your home smell great but it can help you relax and unwind from a busy day. Any of the models we have reviewed will make great options for large rooms, but in particular, we recommend the ArOmis nebulizing essential oil diffuser. We rated the ArOmis as the best essential oil diffuser for large spaces because it can scent your home faster than any ultrasonic model. It’s powerful and quieter than other nebulizers, and the intermittent timer function and automatic shut-off are convenient features that make this one of the easiest diffusers to use.