The Best Essential Oil Diffuser for Large Room: A Definitive Guide

From a list of highest-rated products on Amazon, we’ve chosen the Organic Aromas Raindrop 2.0 as the best essential oil diffuser for large room after a 3-day rigorous testing and analysis.

As a nebulizer type of diffuser, it doesn’t require water or heat to disperse essential oils into the air, preventing molds and ensuring the integrity of the essential oils throughout the process.

Requiring only 20 drops of essential oil, it can provide a strong but not overpowering scent that lasts beyond its 2-hour running time and can cover spaces up to 800 sq ft.

If you prefer continuous diffusion of essential oils with the relaxing action of a water mist, the SimpleTaste  Ultrasonic Cool Mist Humidifier and Essential Oil Diffuser definitely fit the bill.

With a 3-liter water capacity, it can humidify an otherwise dry, cold air and inject a subtle scent of your favorite essential oil without interruption.

No need to refill water; sit back, relax and let it distribute your choice of water- or oil-based essential oil for up to 20 hours at minimum mist setting.

What is an essential oil diffuser?

Essential oils are plant products extracted from their roots, bark, stems, flowers, seeds, or any other parts of the plant.

The same oils that give plants their distinctive smells have also nourished our skin and hair as major ingredients of various beauty products.

Another way to fully reap their benefits to your health is by dispersing them into the air. Essential oil diffusers do exactly that.

Essential oils are highly volatile aromatic compounds, which means they easily change from liquid to gaseous states at room temperature. This is why you can quickly smell the aroma from an open bottle of essential oil even from a distance.

Essential oil diffusers simply streamline the process of spreading the fragrance.

These small apparatuses operate through an electric pump which propels the droplets of essential oil into the air.

Essential oil diffusers are of two types: the more popular ultrasonic diffusers which combine water and oil to form a mist; and the nebulizer type which offers stronger, more concentrated scent as it pushes the oil directly into the air without the need of water/mist.

Note that humidifiers and essential diffusers are two different things.

When people confuse humidifiers with essential oil diffusers, they’re most likely referring to the ultrasonic diffusers. But although the latter adds a little humidity into the air, its functions and features are still significantly different from the traditional humidifier.

Whereas a standard humidifier typically uses a relatively larger water tank (measured in gallons), essential oil diffusers only require at least 80 mL of water for them to function effectively.

Therefore, if you want to get the benefits of both devices at the same time, it would be best to either purchase them separately or buy one of those humidifiers that also function as essential oil diffusers (more on this later).

Who is this for?

For this article, we’ve narrowed down our choices to essential oil diffusers with features or designs that are suitable for large rooms or spaces.

It can be a spacious office or an area in the house occupied by the living room, kitchen, and dining room.

It can also be as large as a commercial establishment like spa, grocery store, or conference room where meditation, yoga, healing practices, spiritual teachings, or workshops are held.

The use of essential oil diffusers in offices aren’t only beneficial to employees’ health but also to their creativity. This holds true for those who rely on arts as their bread and butter: creatives ranging from writers and craftspeople to musicians and painters.

In the book Subtle Aromatherapy, author Patricia Davis shares that some essential oils can activate the right (intuitive) side of the brain.

Depending on individual employee’s preference, the choices may include rose oil which can stimulate the brain to produce original ideas; and rosemary oil that can help turn those ideas into “concrete form.”

Essential oil diffusers are also safe and cost-efficient alternatives to scented candles.

While a typical aromatic candle contains 5-8% essential oils in its wax, most of it are burned and destroyed by the flame.

Meanwhile, there’s also a growing scientific research that proves most scented candles release toxic compounds into the air. These include, but not limited to, formaldehyde, acetaldehyde, and lead.

Many of these hazards and inconveniences don’t exist in essential oil diffusers. Aside from keeping the integrity of essential oils, they also use safe mechanisms to diffuse these oils without releasing harmful chemicals.

The underrated benefits of essential oils (and diffusers).

Some essential oils work best when applied topically. Most of them, however, can only reveal their therapeutic properties when released into the air.

And when you use an essential oil diffuser for large room, the healing benefit of aromatherapy can increase by tenfold. Here are some reasons why you should literally spread the scent of essential oils to as many people as possible:

Calms your mind and body.

Essential oil diffuser allows you to continuously smell the aroma (and get the therapeutic benefits) of essential oils without the need to re-apply them onto your skin.

The scent of lavender, for instance, can help you relax at the end of a stressful day. The soothing fragrance may also establish the ambiance you need for a deeply relaxing meditation or yoga session.

Other essential oils may also relieve physical symptoms when diffused in a room. Rosemary is a natural pain reliever while eucalyptus and peppermint are great decongestants.

Sets the mood for a relaxing massage.

If you own a spa, a few drops of tea tree oil or any scent that is not overpowering can set the mood for a very relaxing massage that your clients will always go back to.

Also Read: 25 Best Homemade Massage Oil Recipes

Using essential oil diffuser in commercial establishments provides customers with a calming atmosphere throughout their stay, eliminating the need for costly scented candles.

Acts as a natural insect repellent.

When getting rid of insects, people usually settle for lotions or candles. However, most of these products contain chemicals that are hazardous for both humans and pets.

Fortunately, there are essential oils you can diffuse to ward off pests or insects without releasing toxic substances.

Citronella, for example, is popularly used as a mosquito repellent. If the smell of citronella turns you off, you can also try peppermint.

For pet owners, you can diffuse eucalyptus or cedarwood for fleas or choose among geranium, rose, thyme, or juniper to get rid of pesky ticks.

Prevents infection.

Unknown to many, essential oil diffusers can also combat airborne diseases by spreading oils into the air.

This is particularly useful for enclosed offices or classrooms where transmission of germs causing flu, colds, or coughs is almost inevitable.

For environments like these that are breeding grounds for infection, you can diffuse essential oils with antibacterial or antiviral properties. Among the recommended choices include cinnamon, eucalyptus, rosemary, thyme, and clove.

Stimulates the brain.

For anyone who has ever worked in an office, it’s a known fact that productivity usually slumps after lunch.

This is a time when most of our body’s energy is expended to facilitate digestion, leaving us sluggish with little motivation left to finish our tasks.

To give yourself and your co-workers a little boost, you can diffuse citrus essential oils. Of course, the scent of choice will largely depend on individual preferences. The good thing with citrus oils is they have an aroma that is stimulating yet not too overpowering to the senses.

Choose among lemon, eucalyptus, grapefruit, or essential oils with a light floral scent to keep you awake and productive.

How we picked: Things to look out for when choosing the best essential oil diffuser for large room.

Type of essential oil diffuser.

As discussed in the previous section, there are two major types of diffuser–one combines oil with water to form a mist (ultrasonic) and the other diffuses oil directly into the air (nebulizer).

Both types are capable of diffusing oils in large spaces, but your choice will ultimately depend on the strength of the scent you prefer.

If you want light fragrance, ultrasonic diffusers can provide it for you. They are equipped with a vibrating diaphragm which vaporizes the water and combines it with the oil.

The resulting cool mist has a relatively more subtle smell because of the water content.

In terms of aesthetics, most ultrasonic diffusers come in attractive, minimalist designs that can fit in any room or office. Plus, the fine mist it releases is in itself relaxing to look at.

For stronger aroma, nebulizer diffusers win hands down.

These small apparatuses blow compressed air to turn the essential oils into a mist. With no water content to dilute the oils, the resulting scent is more concentrated which you can automatically diffuse for a set amount of time at regular intervals.

The downside of nebulizer diffusers is they’re a bit more expensive, generally noisier, and relatively less attractive. Unlike the ultrasonic type, some nebulizers use heat which may affect the integrity of the essential oils they diffuse.


The coverage is perhaps the most important factor you have to consider if you’re planning to use an essential oil diffuser in a large room.

A large living room, for instance, typically measures 15 x 20 ft (4.6 x 6.0 m) or larger. After you determine the exact measurement of your space, you can narrow down your choices to products with the capacity to diffuse oils in larger-than-average settings.

Essential oil diffusers for large spaces usually indicate in their product descriptions the maximum room size they’re most effective for.

Water capacity.

For ultrasonic diffusers, the size or capacity of the water tank isn’t a crucial feature to consider if you’ll only run the diffuser for a short period of time.

An average ultrasonic diffuser with 150 mL-capacity is enough if the diffuser will only be used for a few minutes or so.

In the case of large rooms or spaces where occupants spend the entire day for work, study, or a one-time event, an essential oil diffuser with a large water capacity (at least 300 mL or 500 mL) is indispensable.

A large water tank is ideal for this purpose as it will allow the device to diffuse oils uninterruptedly without the need for refilling.

As a general rule of the thumb, the larger the water tank, the thicker the mist the diffuser produces and the longer it will run without the need for more water.

Contrary to popular belief, you don’t necessarily need a huge essential oil diffuser for a large room. The size of the diffuser doesn’t matter if the quality of scent is your priority.

If you want a stronger smell and keep the scent throughout use, either choose a nebulizer or increase the drops of essential oils in your ultrasonic diffuser.

Ease of use.

To make it on our list, an essential oil diffuser must pass our “grandma test,” meaning any senior who isn’t particularly adept in technology should be able to use the device intuitively.

And by intuitive, we mean the diffuser is easy to:

  • set up (doesn’t require complicated stuff apart from adding water and essential oil).
  • operate (no need to look at the manual to figure out which buttons to click and whatnot); and
  • clean up (a quick rinse with water or alcohol should be enough).

In line with this reasoning, we’ve eliminated products which are too bulky, have non-ergonomic designs, and with options/buttons that are relatively more difficult to navigate.

Noise level.

Most users enjoy running their essential oil diffusers during nighttime. For this reason, we put a little bit of weight on the noise level of the products we’ve selected.

Both types of essential oil diffusers produce varying levels of sounds: the ultrasonic has distinctive vibrating sounds that are not too audible unless you place your ears near the device, while the nebulizer has a relatively louder buzzing sound.

Although it’s difficult to totally eliminate the sound, the best essential oil diffusers for large room allow users to reduce the noise level.

While for some diffusers the decreased volume also means a weaker mist, the almost inaudible noise prevents distraction during an important meeting or any event that requires concentration among participants.

Ambient lighting.

Although it doesn’t have anything to do with essential oils, the LED lights found in most diffusers may end up as a pet peeve if you don’t know how to choose.

Ideally, the indicator lights must be subtle and not annoying. It should allow the users to adjust the brightness and choose whether or not to rotate the lights or keep it steady.

Most importantly, the light must have a switch so you can easily turn it off during the day or anytime you prefer.

Timer option.

According to Aromatherapy Workbook by Marcel Lavabre, an essential oil diffuser should run in an average size room for at least 15-30 minutes, two to three times a day.

For large rooms or open spaces such as stores, spa, offices, or houses with open floor plans, continuous or permanent diffusion of essential oils may be required.

For this reason, it is recommended to choose essential diffusers with large water tank/capacity (see # 3) as well as an automatic shut-off timer. These features are available in medium- to large-size diffusers.

While a large water capacity ensures the diffuser will run continuously without the need to refill water, the timer option allows the device to rest after every few hours, keeping the scent consistent without wasting too much electricity.

To get the best bang for your buck, determine the operating or run time of the essential oil diffuser. Ideally, it should be at least 4 to 6 hours if you’re going to use it in large rooms or open spaces.

The operating time gives you an estimate on how long the scent will last inside the room.

Meanwhile, to determine how much water and oil are diffused every hour, simply divide the water capacity by the operating time.

For example, an essential oil diffuser that can hold 300 mL of water and with an operating time of 4 hours diffuses 75 mL of vapor per hour.


While you can get an essential oil diffuser for as low as $25, the possibility of malfunction within the first year of use is a risk that buyers must be prepared for.

A product that doesn’t offer warranty is a warning sign that the manufacturer is only after the profits and doesn’t care about user satisfaction.

Quality of customer reviews.

As a veteran product reviewer, I know that one of the dirty tactics Amazon sellers use to boost their product is by using fake reviews.

Since it’s becoming incredibly difficult to separate the wheat from the chaff, we used to analyze every product page.

Thanks to this tool, we’re able to verify how genuine every customer review is and whether or not the brand is trustworthy.

The 3 best essential oil diffusers for large rooms.

Organic Aromas Raindrop 2.0 Nebulizing Essential Oil Diffuser.

The convenience it offers is what sets this essential oil diffuser apart from other similar yet cheaper alternatives. As a nebulizer, it’s waterless so it doesn’t require regular refilling unlike the ultrasonic diffusers that need water to form a mist.

The Raindrop 2.0 also stands out among other nebulizing diffusers because it uses air pump instead of heat to distribute the oil.

This durable air pump atomizes the essential oil into millions of micro-particles that your body can easily absorb.

Since it requires neither water nor heat to operate, it ensures the integrity of the essential oil and prevents mold formation.

Design-wise, the Raindrop 2.0 impresses with its attractive glass reservoir and a base made up of rubber and plantation hardwood.

Measuring approximately 5 inches wide and 9 inches tall, this diffuser works best with most essential oils, except thicker varieties (especially those extracted from tree resin), synthetic fragrance oils, as well as carrier oils such as coconut, jojoba, grapeseed, etc.

It has everything we’re looking for in an ideal essential oil diffuser. It consumes up to 20 drops of essential oil per hour, but this amount can vary depending on how long or strong you want the diffuser to run.

And although it’s a little bit on the pricey side, its outstanding features, and overall quality more than make up for its cost.

Type of essential oil diffuser: Nebulizer

Coverage: Provided that you use 20 drops of oil and let the diffuser run for at least 2 hours, the strong scent can fill a whole apartment or any large space measuring up to 800 sq ft/ 70+ sqm.

Water capacity: N/A. This diffuser sprays essential oil directly into the air without the need for water.

Ease of use: It has a dial that allows you to control or adjust the amount of mist that comes out of it.

There’s also a touch-sensitive button that turns the LED light on/off. The latter is a bit annoying because it sometimes requires several attempts before the light turns off.

Otherwise, the options are pretty intuitive to use and there’s no need to read the whole manual to figure out which button is for what.

As for cleaning, the manufacturer suggests rinsing the glass reservoir with isopropyl alcohol at least once a week to keep the diffuser in great condition.

Noise level: As long as you don’t put the dial on full blast, the diffuser will release mist without creating an annoyingly loud sound. If you keep it on low setting, the sound it produces can be as quiet as most ultrasonic diffusers.

Ambient lighting: With LED rainbow-carousel mood lighting which you can turn on/off with the help of a touch-sensitive button or sensor.

It may not respond as quickly or accurately on some occasions, but this is due to the sensitive nature of the sensor. For this reason, the light may turn on simultaneously with the device or the sensor may require few more taps before it turns off.

Timer option: The Raindrop 2.0 is programmed to run for only 2 hours at a time. During this time period, it diffuses essential oil intermittently, meaning it runs for 2 minutes followed by 1 minute of resting phase, repeating the cycle until it reaches 2 hours.

While other nebulizers provide an option to adjust the length of diffusing or to run the device continuously, we found that Raindrop 2.0 offers the ideal running time.

The two-hour intermittent cycle is enough to provide a strong scent covering a wide space while requiring a minimum of 20 drops of essential oil at a time.

Besides, nebulizers with unlimited or customizable operating time are mostly noisier and more expensive than Raindrop 2.0.

If you want to extend its running time, simply reset the device after 2 hours and turn it on again. But since it diffuses concentrated essential oil, 2 hours is more than enough to provide the strong scent you desire.

Warranty: 1 year free parts and service warranty.

Quality of customer reviews: According to Fakespot, 64% of the total customer reviews on the product’s Amazon page are low quality. To avoid being swayed by paid or fake reviews, only look for customer reviews marked with “Verified Purchase.”

SimpleTaste 3L Ultrasonic Cool Mist Humidifier and Essential Oil Diffuser.

Just when we thought no product can get any bigger than Exqline’s humidifier-diffuser, along came SimpleTaste.

Its 3-liter water capacity is the largest of its kind in the market, ensuring an uninterrupted running time of up to 20 hours at minimum mist flow or 10 hours on full blast.

In terms of aesthetics, SimpleTaste’s ultrasonic diffuser looks more elegant and intelligently designed. It blends well with any type of room and has a plastic layer on top which allows you to direct the vapor/mist flow away from moisture-sensitive furniture.

Unlike Exqline, this diffuser has a separate sponge in a small tray where you can drop the essential oil/s of your choice. This feature prevents oil build-up in the tank and also enables you to use both water-based or oil-soluble aromatherapy oils.

In Exqline, only water-based oils are allowed to be mixed with the water as insoluble oils only produce weak or very subtle scent.

Made from durable plastic, this diffuser-humidifier has almost the same features you’ll find in Exqline, except for the water filter which is replaceable after 50 hours of use.

Despite having a larger water capacity, it’s surprisingly almost as lightweight as Exqline’s, weighing 2.31 lbs. versus the latter’s 2.19 lbs.

Whether you’re looking for relief from extreme weather conditions or a nice source of stress-relieving scents, the combined powers of SimpleTaste’s humidifier and ultrasonic diffuser will never disappoint.

Type of essential oil diffuser: Ultrasonic. With the use of a high-frequency ultrasonic oscillation technology, it atomizes water into fine microparticles with whisper quietness.

Coverage: Its large water capacity enables it to humidify and deodorize the air in any large room or space. To see specific measurements, see Exqline’s coverage.

Water capacity: 3L or 0.79 gallons — enough to humidify and deodorize the air in your home or office continuously. At minimum mist, it can run up to 20 hours without the need to refill water.

Ease of use: The water level is very easy to see unlike in Exqline’s. It has a 360° nozzle which you can maneuver or rotate to adjust the mist flow and direction. The water tank can also be lifted off so you can easily take it to the sink for refilling without any spillage.

Noise level: The ultrasonic technology it uses to diffuse essential oils enable it to operate with whisper quietness. Ideally used at night to provide better, more peaceful sleep for babies and adults.

Ambient lighting: Switchable LED light with 7 colors to choose from: Red, Yellow, Orange, Green, Blue, Indigo, and Purple.

Although you can’t adjust the brightness, the colors are gentle enough to provide subtle illumination suitable for sleeping. You can adjust the LED light to stop at one color or switch to auto-cycling colors.

Timer option: N/A. It automatically shuts off once the water level is low for safety reasons and to protect the integrity of the motor.

Warranty: 1-year warranty plus 30-day money-back guarantee.

Quality of customer reviews: 81.3% of current reviews on Amazon are low quality according to Avoid unreliable feedback by filtering out reviews without a “Verified Purchase” tag.

Exqline 1500-mL Aroma Essential Oil Diffuser.

With half-gallon water capacity, this Exqline essential oil diffuser is larger than most products in the market–and for a good reason.

It can fill up your large living room or any space measuring 450 sq. ft. with the scent of your choice.

And thanks to its relatively larger water tank, it will continuously diffuse your favorite essential oils for hours on end without the need to refill it with water every 3 hours or so.

But the greatest selling point of this product–and the reason why we’ve chosen it over similar diffusers–is its versatility.

It’s an essential oil diffuser and humidifier rolled into one. In addition to providing therapeutic fragrance for your space, it also adds humidity especially during dry winter or cold/flu seasons.

Lightweight and minimalistic, it combines the goodness of multiple products so you can save both money and space. It may not be as attractive as Raindrop 2.0, but it compensates with its capacity to run all day without any interruption.

There are two minor issues worth noting. First, the water tends to splash out the moment you remove the lid. This is caused by condensation and won’t cause any inconvenience unless you put the diffuser near furniture or worse, a power outlet.

Essential oils, meanwhile, need to be water-soluble/pure if you want the scent to last. According to the manufacturer, the ideal ratio is 2-3 drops per 100 mL water or about 30-45 drops of essential oil per 1500 mL.

Type of essential oil diffuser: Ultrasonic. It doesn’t use heat so the integrity, as well as the therapeutic properties of the essential oils, will always remain intact.

Coverage: Provided that you use water-soluble pure essential oils, this diffuser can deodorize the air in an area as large as 450 sq. ft. Its humidifying function, on the other hand, can cover rooms of up to 325 sq. ft.

Water capacity: 1500 mL or almost half a gallon. It can continuously run overnight or throughout the day without refilling.

At minimum setting and with a full tank of water, it can operate for up to 20 hours, releasing approximately 30-70 mL of water in the form of mist every hour.

Ease of use: Works like any other humidifier. Simply pour distilled water into the tank and add a few drops of essential oils if you want to enjoy its aromatherapy feature.

It comes with a knob that rotates 270° to let you control the mist output.

The ambient lighting can be turned on/off but the brightness is not adjustable. However, the blue light is perhaps the least distracting color you can choose, should you want a cool light during nighttime.

If LED light is turned on, it’s hard to see the water level without looking at it up close.

The water also tend to condense inside so expect it to drip out once you remove the lid. To avoid hazards, don’t place the diffuser near a power outlet.

Noise level: Thanks to its advanced ultrasonic technology, this diffuser operates with whisper quietness, specifically less than 35 dB of noise which is ideal for sleeping for both adults and babies.

Ambient lighting: It has 7 light color options which can rotate, stay to one color, or no color at all.

Although it is advertised as switchable between bright and dim, we found that the latter doesn’t provide the brightness we think is suitable during nighttime.

Timer option: The mist button allows you to choose how long the diffuser will run. You can select 1 if you want it to work for 1 hour; 2 if you prefer 3 hours; or 3 if you want it to run continuously for 6 hours.

Otherwise, you can imply let the diffuser run without interruption. At minimum setting, it can last up to 20 hours, while maximum mist has a running time of 10 hours.

In case the water runs out, a light will turn red to signal the diffuser has stopped running, a safety feature for those who often forget to turn their diffusers off.

Warranty: 1 year.

Quality of customer reviews: Fakespot analysis reveals it has over 80% high-quality reviews which mean the majority of the customer reviews on its Amazon page are genuine and trustworthy.

The Bottom Line.

As much as we want to pick a single winner, the ultimate choice will always boil down to your preference and purpose of using the essential oil diffuser.

If you want to diffuse oil for a short period of time, perhaps for a few hours of meditation or event, the Raindrop 2.0 nebulizer can provide a strong scent that lasts.

On the other hand, if you’re looking for a diffuser that can run all day or overnight to provide humidity and aroma during dry winter months, we recommend SimpleTaste’s ultrasonic essential oil diffuser.

Remember, a large room or space doesn’t necessarily require an equally large essential oil diffuser.

The SimpleTaste and Exqline products we’ve reviewed, for instance, have large water tanks which perfectly meet the needs of families who want to diffuse relaxing aromas into their bedrooms overnight without waking up to refill water.

If you’re not planning to diffuse oils all day or overnight, using Raindrop 2.0 nebulizing diffuser for two hours can already provide the necessary scent that is both strong and long-lasting.

Alternatively, you can simply use one of those regular-sized essential oil diffusers and just add drops of essential oils every now and then to achieve the level of scent you desire.

Tips and Warnings.

*Some essential oils release compounds that have been shown to cause breathing difficulties in the past. Although the American Academy of Allergy Asthma & Immunology doesn’t directly link the use of essential oils to respiratory disorders, consumers are advised to take extra caution when introducing essential oil diffusers in households of patients with asthma.

*Between ultrasonic and nebulizer, the former is the diffuser of choice for asthmatic patients because it provides more control over the quantity of essential oil being diffused.

*Keep bottles of essential oils away from small children. In addition to their attractive smell, unsuspecting kids might mistake the essential oils for an edible snack.

*Put labels on the bottles to prevent accidental poisoning. Designate a specific storage area where you’ll put both the essential oils and the diffuser, ideally in an elevated cabinet that children will find hard to reach.

*When using a diffuser in your office, be aware of other people’s sensitivity or aversion to specific scents. Some of them may associate a scent with a negative experience. Others may just find it too strong or overwhelming.

Hence, it’s your responsibility to ensure everyone is fine with the specific blends you’re diffusing to avoid negative reactions. To do this, bring your favorite essential oils to your workplace and let your co-workers sniff and identify which ones will perfectly satisfy everyone.

*Clean your essential oil diffuser after each use. Instructions on how to properly clean it may vary depending on the type of diffuser and the manufacturer.

Giving it a quick rinse using water and wiping it with clean damp cloth can help remove the leftover oils. When not removed, the oils may build up and become corrosive. They may also mix with other essential oils you’ll use subsequently, negatively affecting your aromatherapy experience.