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You’ve seen a diffuser emit steam into the air, but you’ve also seen a humidifier do the exact same thing. So which one are you supposed to get and what are the differences?
These devices often look so similar, but there are some valid differences that will probably affect your purchasing decision.
You aren’t alone if you’re confused about the difference between humidifiers and diffusers, thinking they might be the same thing. And the confusion is understandable because they have nearly identical physical characteristics.
It’s difficult to tell the difference between the two without having a detailed understanding of how each works and the factors that set them apart.
In this article, we will compare both of these appliances so you can gain a better understanding of their similarities and differences and learn exactly which one is best for you.
Don't have time to read the entire article? Here are top picks for the best diffusers and humidifiers:
Top Choices for Diffusers:
- Best Option for Small Spaces: InnoGear Aromatherapy Essential Oil Diffuser
- Best Option for Large Spaces: URPOWER Essential Oil Diffuser
- Most Aesthetically- Pleasing: BZseed Aromatherapy Essential Oil Diffuser
Top Choices for Humidifiers:
- Best Warm Mist Humidifier: Proscenic 807C Humidifiers
- Best for Baby's Room: Vicks Warm Mist Humidifier
- Easy to Fill: Honeywell HWM-340B Easy-to-Care Warm Mist Humidifier
Now, let’s start by looking at what a diffuser is and some recommendations for specific diffusers that are on the market today.
What’s the Main Difference Between a Diffuser and Humidifier?
We will go into more detail, but if you’re looking for the primary difference between the basic purpose of these two devices, the answer is in their functions.
A humidifier increases the humidity in a room by dispersing water droplets through the air. It transforms water into vapor, which then diffuses into the air.
In contrast, the purpose of a diffuser is to disperse essential oils into the air. Diffusers may also increase the humidity around you, but this is not the main purpose they serve.
Both appliances carry out their function in similar ways, and by using the same physics.
Now let’s go into more detail.
What Is a Diffuser?
Diffusers are designed to be used with essential oils, so this is a main factor to consider. Diffusers are smaller than humidifiers and don’t hold nearly as much water, so they don’t add as much moisture into the air.
When considering whether to purchase a diffuser or humidifier, note that it’s typically not recommended to use essential oils with a humidifier, however, many humidifiers these days are made with a special cup to add in essential oils if you wish.
That said, there are a lot of diffusers on the market, ranging from ones that you can carry in your pocket to fan-based diffusers that diffuse their mist into only a few square feet of space.
Diffusers hold a maximum of 300-500mL of water, and there are some that don’t hold water at all. For diffusers that do use water (which is most of them), it’s required that you use distilled water (not tap water) to get the best results. This prevents mineral buildup, which can happen if you use tap water.
Diffusers are often favored by people who live alone or with others who enjoy the same essential oils, as a diffuser is typically used to enhance a room’s aroma and offer specific health benefits. There are essential oils for:
Diffusers can also be used to help eliminate bacteria and fungus in a room, which can help prevent health issues, as the antimicrobial properties of many essential oils can benefit your health.
For example, if you have respiratory issues, diffusers can be helpful when using oils such as tea tree oil, as it has antimicrobial properties; and peppermint and eucalyptus oils can help promote respiratory health as well, as they help you breathe by clearing out your airways.
Keep in mind that it’s important to do your research to find which essential oils are right for you.
There are four types of essential oil diffusers to choose from, including evaporative, heat, nebulizing, and ultrasonic.
- Evaporative diffusers
- Heat diffusers
- Nebulizer diffusers
- Ultrasonic diffusers
Evaporative diffusers: Simply add drops of essential oil to the diffuser filter. A fan then sends air through the filter to stimulate the oil’s evaporation in order to spread the aroma throughout the room.
Heat diffusers: These are similar to evaporative diffusers, but they use heat instead of a fan to disperse essential oils.
Nebulizer diffusers: These are often thought to be the most effective type of diffuser. Oil is added into a tube where a suction brings the oil to the tip of the tube and a small jet blows air across it. When air blows across the oil’s surface, small oil droplets are diffused through the room.
Ultrasonic diffusers: These are also humidifying diffusers. Essential oils are added into the water, which then remain on the surface. The device agitates the water using vibrations, which causes the oil to divide into small particles, which is then dispersed into the air in a fine mist.
Ultrasonic humidifiers use 2.4 million vibrations per second to disperse your essential oil into the air. Because this option doesn’t use heat, which can break down the properties of essential oils and make them less effective, ultrasonic vibrations are the best way to go if you want to get optimal benefits from your essential oils.
The only downsides that people note about diffusers are:
However, when used correctly, the cost is indeed worth the benefit. Also, while most diffusers are made with a built-in light that you can’t turn off while the diffuser is in use, some people appreciate the dual ability to act as a night light.
If you have children, you may find a lighted diffuser to be beneficial, and the lights are typically adjustable, so you can control the brightness. When it comes to noise, if you're using a diffuser to help you relax or concentrate, you will want to find one that emits little to no noise.
What Are the Best Diffusers on the Market?
Best Option For: Small Spaces
This small, portable diffuser is a quiet option that can be used in smaller areas where you want to enjoy your essential oils.
Along with providing the known benefits of essential oils, this diffuser can also be used as a night light. It comes with seven color options that you can either set to just one or allow the unit to cycle through the colors like a rainbow.
This dim illumination feature is great for children in addition to the diffuser’s ability to improve children’s breathing by adding moisture into the air.
There are convenient buttons on the front of the diffuser that allow you to adjust the settings for lights and mist.
The InnoGear essential oil diffusers give you up to three hours of continuous mist, but can also be set to disperse the oil in 30 second intervals, allowing it to work for up to six hours. The reservoir holds about 100 milliliters of water, to which you can directly add a few drops of essential oils.
This is a great option for an office, a small room, or your bedside table.
Best Option For: Large Rooms
This diffuser is designed for large rooms, as it holds 120 milliliters of water. In addition to being a diffuser, it can also be used as a night light and humidifier. This option is easy to use and only needs to be cleaned once a week.
To use the diffuser, fill the reservoir up with water to the fill line and add in a few drops of your favorite essential oil. There are buttons on the front of the diffuser that let you adjust the light and mist settings, allowing the unit to work as a nightlight as well.
This diffuser has an automatic shut-off feature once it runs out of water. It can provide around three hours of steady mist or about six hours of mist when it’s on its intermittent setting. This diffuser is affordable, easy to use, and easy to clean, so it’s a great option if you’re looking for simplicity.
Best Option For: Aesthetically Pleasing
This is a good option if you're looking for a diffuser that can run for a long time and provide fragrance for a large space. This attractive unit, which is available in a light or reddish-brown wood grain, can run for hours while putting out a continuous mist covering up to 82 square feet of space.
It produces 30 milliliters of moisture per hour. Along with being able to create a continuous stream of scented mist, you can also use a timer to set the unit to turn off after one, three, or six hours.
Like the others, this diffuser is easy to use and to clean. Simply remove the lid and add water and a few drops of essential oil to the reservoir. The lid comes off easily, so while you don't have to struggle with it, it may spill if you bump into it.
This essential oil diffuser can also work as a night light and a humidifier. You may find that the adjustable lights from the unit are soothing even when you’re not trying to sleep.
What Is a Humidifier?
A humidifier is a popular appliance used among people living in dry climates or those who can’t tolerate the dry air of winter. Humidifiers can help ameliorate health issues such as:
HVAC.com reports that your home’s humidity level should remain between 30% and 50%, which can be accomplished with the help of a humidifier, as it helps your rooms maintain this comfortable level of moisture.
Just like diffusers, there are four types of humidifiers, including warm mist, evaporative, impeller, and ultrasonic.
There are some downsides that people have reported about humidifiers, including:
What Are the Best Humidifiers on the Market?
Best For: Warm Mist Humidifier
This warm mist humidifier comes with an app so users can easily adjust the humidity levels in their homes.
You can also use the app to program scheduled humidification times and modes. It has a 5.5-liter water tank that will emit mist for up to 36 hours. This humidifier also comes with seven options for speed, so you can customize it to your needs.
The rotating nozzles have a full 360-degree range, ensuring the humidity is evenly dispersed throughout your room. Plus, unlike most humidifiers, this one features a dedicated container for essential oils if you want to enjoy aromatherapy.
The unit includes sensors that will automatically detect the amount of humidity in the air and adjust the amount of mist that is being emitted accordingly.
At nighttime, the unit switches to a night rest screen, allowing you to sleep easily if this humidifier is in your bedroom.
This product comes with a HEPA filter to make sure that the air you’re breathing is clean and healthy.
Finally, it comes with a memory function that keeps track of the last humidification mode that you used. This is convenient if you typically only use one mode because you don’t have to reset the humidifier every time you use it.
Best For: Using in a Baby’s Room
This is the best option if you’re looking for a warm mist humidifier for your baby’s room. It offers a whisper-quiet sound, mimicking white noise, which can help your baby sleep. It also has a soft glowing nightlight. This unit measures 12″ x 7.9″ x 14.2″ and is ideal for medium-sized rooms.
Whether you want some relief from a cough or cold or you need some comfort from the dry air of winter, this Vicks humidifier adds critical moisture into the air to help both you and your baby feel better.
The Vicks Warm Mist Humidifier boils water to a 96% bacteria-free steam vapor that is then released by the humidifier in a warm, visible mist. The unit has two settings that you can adjust to your preference and it also includes a medicine cup to use for liquid inhalant medicine or essential oils.
This humidifier is filter-free and the one-gallon tank can run for up to 12 hours before users have to refill it. The tank includes a handle, making it easy to lift and carry, and it has an auto shut-off feature that will turn the unit off once the water runs out. However, it’s easy to see when the water is running low through the transparent tank.
Best For: Easy to Fill
The Honeywell Warm Mist Humidifier comes with a top-fill design, making it easy to fill when you find you’re running low on water. You can add water to this humidifier just as you would add water to a plant by pouring it into the top of the unit.
This 1.3 gallon option also includes an adjustable humidistat that will turn your humidifier on automatically so you can maintain a preset humidity level. It also features a reset light that indicates when the tank needs to be refilled, and an auto shut-off feature for when it’s completely empty.
This humidifier includes a medicine cup that you can use for either vaporized medicines or essential oils. This is a great option for larger rooms and will run for 24 hours on the low setting while emitting a vapor that is 95% bacteria-free.
This product comes in black or white so you can pick the option that works best for your home’s decor.
How to Pick the Right Product Based on Your Needs
Your ultimate choice will depend on a few factors. The main things to consider are:
Do You Have a Dry Climate?
If the air in your home is noticeably dry, you’ll want to choose a humidifier. However, if your home is already humid and you simply want the benefits from aromatherapy, a diffuser is the better option.
What's Your Budget?
While you can find both products in a variety of price ranges, getting a higher quality product will end up paying for itself because it will last much longer than a lower-cost option. It may take some research to find either product that fits into your budget.
What's the Size of the Room?
The bigger the room, the larger the device you will need. Humidifiers are usually better for large rooms because they typically hold more water than a diffuser. Diffusers are better for small rooms or desks because they’re not designed to disperse liquid as far.
Are You Looking for Therapeutic Benefits?
A diffuser is your best bet if you’re looking to gain therapeutic benefits from essential oils. While humidifiers can help with this also, the oil gets so diluted that it fades much faster. Even if your diffuser requires you to add water, you’ll still get a more potent scent.
Final Thoughts on Diffusers vs Humidifiers
Ultimately, if your primary concern is maintaining an optimal level of humidity, it’s best to get a humidity reader and humidifier, as they’re specifically designed to fix this issue.
If you’re focused on distributing essential oils through the air, it’s best to get an essential oil diffuser that’s designed especially for this purpose.
Hopefully after reading this article, you’ve decided whether a humidifier or a diffuser is best for you. Both products certainly have their advantages.
Because of this, you may want to have a humidifier and a diffuser and use them at different times based on your need at that moment. You may want a diffuser in your bedroom for when you want to relax, but a humidifier in your child’s room to help maintain their respiratory health.
And if you're looking for more reviews to help you make a decision, check out these articles:
- 11 Best Rated Essential Oil Diffusers
- 25 Best Essential Oils for Energy, Focus, and Motivation
- 10 Best Warm Mist Humidifiers on the Market
Connie Mathers is a professional editor and freelance writer. She holds a Bachelor's Degree in Marketing and a Master’s Degree in Social Work. When she is not writing, Connie is either spending time with her daughter and two dogs, running, or working at her full-time job as a social worker in Richmond, VA.