Humidifiers vs. Diffusers

By: Evan Scoboria, Last updated: June 28, 2023

Navigating the world of air quality devices can often seem like a maze with various types of products, all promising to transform your indoor environment. Two such machines, humidifiers and diffusers, are often discussed together, leading to confusion about their specific uses and benefits. In this article, we aim to clear up any confusion by explaining the functions of these devices, outlining their differences, and providing guidance on when each might be most beneficial.

Humidifier and Diffuser

Understanding What a Humidifier Is

A humidifier is designed to increase the humidity levels in a room or house. These devices release water vapor or steam into the air, thus elevating the overall moisture content in the environment. The primary purpose of a humidifier is to alleviate dryness and create a more comfortable atmosphere, especially during winter or in arid climates when the air can become particularly dry.

Humidifiers come in various types, including warm mist, cool mist, ultrasonic, and evaporative humidifiers. While their designs vary, all humidifiers function by taking water from a reservoir and converting it into a mist or steam. Warm mist humidifiers do this by boiling water, while cool mist humidifiers create a mist without heat. Ultrasonic humidifiers use high-frequency vibrations to produce mist, and evaporative humidifiers utilize a fan to blow air through a wet wick filter.

The moisture that humidifiers add to the air can help alleviate symptoms associated with dry air, such as dry skin, itchy eyes, scratchy throats, and even problems with respiratory health. They're instrumental when indoor heating systems can significantly decrease home humidity during colder months.

Unlike diffusers, humidifiers are not designed to disperse essential oils. Some models may allow for this function, but their primary purpose is generally to increase humidity rather than diffuse fragrances.

Understanding What a Diffuser Is

A diffuser distributes essential oils into the surrounding air, creating a calming, fragrant atmosphere. These devices have become a favorite in the wellness community due to their role in aromatherapy. This holistic healing treatment uses natural plant extracts to promote health and well-being.

Diffusers come in several types, including ultrasonic, nebulizing, heat, and evaporative diffusers. Each of these operates differently to disperse essential oils into the air, but they all serve the same purpose: spreading a pleasant aroma around your space.

Ultrasonic and nebulizing diffusers create vibrations that disperse the essential oils into fine particles that the body can inhale and absorb. On the other hand, heat and evaporative diffusers use heat and a fan to evaporate the essential oils into the air.

Diffusers are typically smaller than humidifiers and are intended to cover a smaller area. Most models are perfect for personal spaces, like bedrooms, bathrooms, or home offices. Their compact size and ability to create a soothing ambiance make diffusers great additions to any relaxation or wellness routine.

However, one crucial thing to note about diffusers is that while they can emit a light mist, much like a humidifier, they are not designed to significantly increase the humidity in a room. They are mainly for spreading essential oils, and the small amount of moisture they may add to the air is just a byproduct.

If you're seeking a way to make your home smell great, create a soothing atmosphere, or reap the benefits of various essential oils, a diffuser might be the gadget for you. However, if adding moisture to your indoor air is your primary concern, a humidifier would be more suited to your needs.

Critical Differences Between Humidifiers and Diffusers

Humidifiers and diffusers, although they share some similarities, also exhibit key differences that make them suited to specific uses and environments. Let's break these down:

  1. Function: A humidifier's primary function is to add moisture to the air, thus helping alleviate symptoms of dry air like chapped lips, dry skin, sinus congestion, and even respiratory ailments. On the other hand, a diffuser is designed to spread essential oils in the air, often used for aromatherapy. It diffuses the oils into tiny particles that can be inhaled and absorbed by the body, promoting relaxation, focus, or other wellness benefits, depending on the oils used.

  2. Capacity: Depending on the model, Humidifiers generally have larger water tanks designed to cover a larger area, like a room or an entire house. Diffusers usually have a smaller water capacity and are ideal for smaller spaces.

  3. Running Time: Given their larger capacity, humidifiers can often run longer - some models can run up to 24 hours on a single fill. Diffusers tend to have shorter running times with smaller tanks, often between 3 to 6 hours.

  4. Effect on Air Quality: Humidifiers can help increase the relative humidity in a room or home, especially useful in dry climates or during winter when heating systems can dry out indoor air. On the other hand, by dispersing essential oils into the air, diffusers can create a pleasant aroma in your home. Still, they do not have a significant impact on humidity levels.

  5. Use of Essential Oils: While both devices can typically use essential oils, not all humidifiers are designed for this purpose. Using oils in a humidifier not intended for this use can cause damage or require more frequent cleaning. Always check the manufacturer's instructions before adding oils to a humidifier.

While both devices can enhance your home environment, your choice between a humidifier and a diffuser will largely depend on your needs, be it increasing indoor humidity, creating a fragrant atmosphere, or a bit of both.

When to Use a Humidifier vs. a Diffuser

The decision to use a humidifier vs. a diffuser largely depends on your specific needs and goals for the environment in your home.

A humidifier will be an excellent option for dealing with dry air in your home, particularly in the cooler months. This device adds moisture to the air, helping combat dryness that can cause dry skin, irritated throat and sinuses, cracked lips, and even difficulty sleeping. So if your primary goal is to add moisture to your indoor air, you'd want to lean towards a humidifier.

On the other hand, if you're interested in harnessing the benefits of aromatherapy, a diffuser would be more appropriate. Aromatherapy can provide various wellness benefits, including stress relief, mood enhancement, and improved sleep. Diffusers disperse essential oils into the air, creating a soothing, fragrant atmosphere in your home.

It's also important to note that combination units on the market function as both a humidifier and a diffuser. These can be a good option if you want to add moisture to your air and enjoy the benefits of aromatherapy. But remember, these devices may require more frequent cleaning and maintenance due to the use of essential oils.

Your choice between a humidifier and a diffuser will depend on whether your primary goal is to increase humidity in your home or enjoy aromatherapy's benefits. And, as always, proper maintenance of whichever device you choose is critical to ensuring its effectiveness and longevity.

Frequently Asked Questions

  1. 1. Can I use a humidifier as a diffuser? While some humidifiers have built-in diffusing capabilities, it's important to note that not all do. Always check the specific features of your device. Standard humidifiers are not designed to handle essential oils and can become damaged or even dangerous if oils are added.
  2. 2. Are there combination devices that work as humidifiers and diffusers? Yes, there are devices on the market that combine the capabilities of both a humidifier and a diffuser. These hybrid devices can humidify your space while diffusing your favorite essential oils.
  3. 3. Can I use a diffuser in a baby’s room? Yes, you can use a diffuser in a baby's room, but you should be cautious about the types of essential oils you use. Some oils may not be suitable for babies or young children. Always consult with a healthcare provider or aromatherapy specialist if you're unsure.
  4. 4. If I have dry skin, should I choose a humidifier over a diffuser? A humidifier could be a better choice for dry skin, as it works to add moisture back into the air, which can help keep your skin hydrated. On the other hand, a diffuser primarily disperses essential oils for fragrance and therapeutic purposes.
  5. 5. Can I add essential oils to the water in my humidifier to make it work like a diffuser? Adding essential oils to a standard humidifier is not recommended unless it's designed to handle them. Essential oils can damage the plastic in many humidifiers and potentially cause harmful particles to be released into the air. Always check the user manual or consult the manufacturer if you're unsure.


Choosing between a humidifier and a diffuser depends on your needs and circumstances. A diffuser could be your best friend if you're primarily concerned with creating a therapeutic, fragrant environment to promote relaxation and well-being. Its role in diffusing essential oils into the air, enhancing your mood, or supporting better sleep is undeniably remarkable.

Conversely, a humidifier might be the best fit for you if you're grappling with issues related to dry air in your environment—dry skin, irritated eyes, or respiratory discomfort. By adding moisture back into your living space, a humidifier ensures you and your loved ones enjoy a comfortable and healthier indoor environment, especially during those dry months.

Bear in mind that some modern devices combine the functionalities of humidifiers and diffusers, offering you the best of both worlds. However, paying attention to the features and specifications is crucial to ensure they meet your requirements. After all, the end goal is to create a comfortable and health-promoting environment in your home.