How to Find the Best Oil Diffuser for Large Rooms (2017 Version)

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Oil diffusers are the cornerstone of aromatherapy. Let us help you find the best oil diffuser for large rooms in our comprehensive guide – updated for 2020.

Why You Need an Oil Diffuser and How to Choose One

What to Know before You Buy

Oil diffusers allow you to enjoy aromatherapy in the comfort of your own home, and they also allow you to enjoy the beneficial properties of essential oils (more on that soon). But there are some important things you should know before you buy.

URPOWER 500ml Aromatherapy Essential Oil Diffuser Humidifier with 4 Timer Settings

Our favorite model for 2020 – large tank and 3-in-1 design

Square Aromatherapy Essential Oil Diffuser Humidifier

Largest tank and contemporary, attractive design

VicTsing 300ml Cool Mist Humidifier

A practical diffuser in a compact design that still covers large rooms

Essential Oils Need to be Used Safely

Essential oils are highly concentrated, and it’s easy to go overboard when adding droplets to your diffuser tank.

According to Wellness Mama, it takes:

  • 150 pounds of lavender flowers to produce a single pound of lavender essential oil
  • 256 pounds of peppermint leaves to produce a single pound of peppermint essential oil
  • Several thousand pounds of rose petals to produce a single pound of rose essential oil

Because they are so potent, essential oils should never be applied directly to the skin. Even when mixed with a carrier oil, certain oils can make your skin more sensitive to the sun.

The good news? One of the safest ways to use essential oils is with a diffuser.

The Benefits of Using an Oil Diffuser

Why should you even bother buying an oil diffuser? Why not just buy one of those plug-in air fresheners?

Oil Diffusers Fill Your Home with Natural Scent

As Quinessence Aromatherapy explains, essential oils are the fragrant, highly-concentrated, and naturally-occurring volatile compounds found in plants. A single essential oil can contain over 100 different chemical compounds. Quinessence also says that most oils have antiseptic properties and some have antifungal, antibacterial and antiviral properties.

When you diffuse essential oils, you fill your home with natural fragrance from plants – not synthetic chemicals.

The problem with scented candles and similar products, according to Woman’s Day, is that they contain paraffin. These candles produce chemicals, like alkenes and toluene – both of which can be harmful to humans.

So if you want your home to smell fresh, an oil diffuser is the more natural approach.

soothing oils

Essential Oils Can Have Therapeutic Effects

Essential oils have been shown to have some therapeutic properties.

  • This study found that some essential oils can fight superbugs.
  • Another study found tea tree oil is more effective than hand soap against germs.
  • This study found that lavender oil helps people sleep.
  • There is some evidence that eucalyptus oil can help with respiratory issues.

When diffused, essential oils may help provide you relax, fight off illness, or even keep your airways clear during cold season. Are these oils more effective than conventional medical treatments? Probably not. But they may help speed up recovery or enhance treatment.

Oil Diffuser Buying Guide – What to Look For

Just like with any other product, some oil diffusers are better than others. Here are a few things to look for when searching for a quality model.

Mist Control

Many modern oil diffusers have mist control functions that allow you to choose between high and low mist. Essentially, this controls the intensity of the mist.

While not absolutely essential, this is a feature you may want to seriously consider – particularly if you plan to use the diffuser at night. A less-intense mist may be better suited for night-time use when you may be exposed to the oils for a longer period of time.

It’s also nice to have the option of changing the mist intensity if you have guests who may be sensitive to the fragrance.


Timers are another nice function because they give you more control over the length of your sessions. Most offer timers for one hour, three hours and six hours.

If you set a timer, you don’t have to worry about using the diffuser for longer than the recommended time.


Some diffusers can cover larger areas than others. Typically, you can judge how much coverage you will get by checking the size of the water tank. The larger the tank, the larger the coverage area in most cases.

Check the product description to see if the unit you’re considering will provide you with enough coverage for the room it will be used in.


Does the unit have an automatic shut-off feature? Most modern diffusers will shut off automatically when the tank runs out of water. This safety feature prevents the unit from overheating or burning any essential oil residue left behind.

Automatic shut-off is another feature you may want to seriously consider when choosing a diffuser for your home.


Is the diffuser easy to maintain? Some units are easier to fill and clean than others. Others require special maintenance after a certain number of uses.

Make sure you understand how to care for the unit before buying it. Otherwise, you may wind up with a machine that’s more work to maintain than you bargained for.

The 5 Best Oil Diffusers for Large Rooms

Square Aromatherapy 700ml Ultrasonic Oil Diffuser

The Square Aromatherapy diffuser has one of the biggest tank sizes on the market – 700ml. Its modern square design and color-changing lights make this model a great option for use during sleep or episodes of anxiety.

The 700ml tank provides over 20 hours of use on low mist mode and over 10 hours of use on high mist mode. I’ve fallen asleep with a diffuser on high and have woken up with a headache. The low mist option would have been nice to have for those nights.

A large tank also means that you don’t have to get up in the middle of the night to refill.

Square’s diffuser has multiple functions that give you more control over your experience. There are two mist settings: high and low. You also have the option of setting a timer for your session: 1 hour, 3 hour and 6 hour.

The brightness of the light can also be controlled. In fact, you can turn off the light completely if you want to use this diffuser while you sleep.

If you’re health conscience, you’ll appreciate that this diffuser is made with BPA-free materials. And the modern cube design allows this diffuser to blend in nicely with just about any type of home decor.


  • Large tank allows you to diffuse for longer and in larger rooms
  • Mist settings and timers give you more control over your experience
  • Multiple LED color lights to choose from
  • Can run up to 20 hours on low, making it one of the longest-running diffusers around
  • Square design is modern and sleek


  • Makes some noise

The only minor issue with this diffuser is that isn’t silent. If you plan to use this diffuser while you’re awake, this shouldn’t be much of an issue, but if you want to sleep with it on, the sound may become a nuisance.

With that said, the Square’s large tank may make it a good choice for you if you want to treat large areas of your home.

URPOWER 500ml Oil Diffuser Humidifier

URPOWER’s 500ml diffuser is versatile, easy to use and gives you more control over your experience. The extra-large tank also allows you to treat large rooms and diffuse for longer.

Using just this one diffuser, you can treat up to 430 square feet of space.

The URPOWER diffuser is a 3-in-1 model: It works as an oil diffuser, humidifier and night light.

The 500ml tank gives you about 10 hours of use, and the unit will shut down automatically when the tank runs out of water.

While this model does not allow you to control the mist (high or low), it does have three timer settings: 60 minutes, 120 minutes and 180 minutes. You also have the option of just leaving the unit on and allowing it to run until the tank is empty.

If you don’t want to use essential oils, you can simply fill the tank with water and use it as a humidifier. The LED light function can also be used as a night light, and you have the option of changing the light color with the touch of a button.


  • Extra-large tank can treat large areas of your home and allow for longer diffusing
  • Can also be used as a humidifier and night light
  • Timer gives you more control and allows you to use the unit at night without worry
  • Can be used in spas and other large rooms


  • Unit must be cleaned regularly

The URPOWER unit needs to be cleaned at least once a week, but daily cleaning and refilling is required if you use the diffuser daily. This may be a minor inconvenience if you do not empty the tank during use and are forced to pour essential oils down the drain.

With that said, this unit can treat very large rooms and offers an easy-to-use design.

The URPOWER might be a good choice if you want a versatile diffuser and a night light.

Aroma Essential OliveTech 400ml Oil Diffuser

Aroma Essential’s OliveTech diffuser offers many of the same features as the Square and URPOWER, but has a smaller tank and unique design.

The vase shape gives the OliveTech a sleek look and turns it into a decorative piece for your home.

The 400ml tank treats large rooms and provides 8-12 hours of use. And when the water runs out, the unit shuts down automatically.

The OliveTech has a mist function and timers: 1-hour, 3-hour and 6-hour. There are also two mist settings: high and low.

The mood-enhancing lights allow you to choose from seven colors and to adjust the brightness of the LED light. The ultra-quiet design may also make this a good diffuser to use during sleep.


  • Ultra-quiet operation is great for use during sleep and relaxation
  • Large tank gives you up to 12 hours of use and can treat large rooms
  • 7-color LED light is soothing
  • Timer allows you to set-and-forget the unit


  • Aroma isn’t as strong as other diffusers

The only gripe with the OliveTech diffuser is that the aroma isn’t quite as strong as other units. Adding a few extra drops of oil may help resolve the issue.

Aroma Essential’s OliveTech diffuser may be a good option for you if you want a diffuser with a unique design and color-changing LED features.

VicTsing 300ml Oil Diffuser

VicTsing’s 300ml diffuser is more compact in size, but can still treat larger rooms. The wood grain design also gives this unit a contemporary look.

I have used diffuses with similar-sized tanks and had been disappointed by the mist output. The VicTsing produces up to 30ml of moisture per hour, which would have been great to have when I was doing aromatherapy sessions every day.

Even though this unit has a smaller tank than the other models we’ve reviewed, it still provides up to 10 hours of continuous use. And when the water runs out, the unit shuts down automatically.

Four timer settings are available: 1-hour, 3-hour, 6-hour and steady/on. The timer setting is great for use during sleep because you won’t have to worry about going over the recommended time limit.

Like most other diffusers, this model also has an LED light that changes colors. You can choose one specific color, or you can allow the unit to cycle through colors. The brightness of the light can also be adjusted to your liking, which is great for night-time use.


  • Compact size makes it easy to place this diffuser just about anywhere
  • Provides up to 10 hours of continuous mist
  • Timer setting allows you to set-and-forget the diffuser
  • The color-changing LED adds ambiance


  • Tank is smaller

The only complaint with the VicTsing is that the tank is smaller than the other units on our list. With that said, it still provides up to 10 hours of mist, which makes it great for night-time use.

If you are short on space or just want a compact diffuser, the VicTsing may be a good choice for you.

Anjou Naturals 300ml Oil Diffuser

Offering up to eight hours of continuous use, the Anjou Naturals oil diffuser is the smallest model on our list, but it still provides more than enough power to treat a large room.

The 300ml tank provides up to eight hours of use, or you can set a timer for one hour, three hours or six hours for a more controlled session.

If you fall asleep with the unit on, the unit will shut off automatically when the tank runs out of water.

The contemporary design of this unit allows it to blend in with just about any home décor, and the LED light is soothing. Like most other diffusers, this unit’s light has seven colors to choose from.

Anjou also includes mist control, so you can adjust the intensity of the aroma with the touch of a button. The unit is quiet, although not silent, so it can be used while sleeping.


  • Provides up to 8 hours of continuous use
  • Timers give you more control over the length of your session
  • LED lights are soothing, and the colors can be changed
  • Mist control allows you to choose between intense fragrance and a longer-lasting session


  • Mist is weak compared to other units

The Anjou Naturals diffuser produces a weaker mist compared to other units, and that’s because it has a smaller tank. Adding extra drops of essential oils can help combat the problem.

The Anjou Naturals diffuser may be a good fit for you if you want a unit with a smaller tank and a more soothing selection of light colors.

Which Oil Diffuser is Best for Large Rooms?

All five of these oil diffusers are great choices, but we prefer the URPOWER. The large tank gives you more than enough coverage for even the largest of rooms, and it can also function as a humidifier and nightlight. The versatility of this machine, we think, provides a little more value.


aroma oils

With that said, each unit has its own benefits and uses. We’ve done our best to explain the best uses and scenarios for each model in our reviews. Consider your own personal needs when choosing a unit for your home.