The Best Filter-Free Humidifiers You Can Get For Your Home


Humidifiers are a great way to help ease breathing problems, dry skin, and other respiratory issues. They also help in relieving cough and cold. While there are different types of humidifiers, the most popular ones today are the filter-free models. They offer a lot of conveniences and they are also more practical in the long run since there are no filters to replace every now and again.

But how effective are they as compared to filtered humidifier types?

In this guide, we will discuss how they generally work and the features that make them suitable for you.

Best Filter-Free Humidifiers Comparison Table 2018

Crane Drop EE-5301-FFP4$$Single room
Safety 1st Ultrasonic 3604$Single room
Air-O-Swiss AOS 71474$$$$Single room
Holmes HM2610-TUM4$$$Single room
Air-O-Swiss AOS 71464$Portable

How to Choose the Best Filter-Free Humidifiers

Here are some things that you need to consider when choosing a filter-free humidifier for your home:

  • Hard Water vs. Soft Water

    Since there are no filters to purify the water, it is important for you to know if you are using hard water or soft water in your home. Filtered humidifiers are best when you are using hard water as compared to filter-free units. If you really want to use a filter-free humidifier and have hard water at home, you can use distilled water for the unit.

  • Demineralization Cartridge

    Ultrasonic humidifiers may not require filters but they can be used with a special cartridge. If you are using hard water, it will be helpful if the humidifier comes with or has an available demineralization cartridge because hard water includes mineral contents which could affect the mist and also shorten the lifespan of your humidifier.

  • Cleaning and Maintenance

    Check how easy it is to clean both the tank and the base. Also, how often do you have to rigorously clean the unit? Some require you to use special cleaning solutions intended for specific brands. Most tanks need to be filled from an opening at the bottom. You need to make sure that this opening is wide enough to fit under your sink for easy filling and that you can reach inside when doing regular maintenance.

  • Variable Mist

    It will be very helpful if you can adjust the amount of mist that comes out of your humidifier. Most have a dial which lets you set the mist from low to heavy. Low cool mist is great for those who have breathing problems while high mist or heavy mist can help in dry skin.

  • Automatic Humidity Adjustment

    Some advanced models offer automatic adjustment which auto programs the humidity output depending on the humidity level inside the room. Check out our Aprilaire 700 Whole House Humidifier w/ Automatic Digital Control, .75 Gallons/hr Review. But manual control is also great so you can adjust it to your comfort and preferences.

  • Warm or Cool Mist

    Filter-free humidifiers as mentioned can be either cool or warm mist. It really depends on your preferences and perhaps, the climate and weather outside. Cool mist is best during the warmer seasons and warm mist are great during the winter or cold weather. It might also add extra comfort if you can add medicines to be infused in the mist like most of Vicks humidifiers.

  • Noise

    If you are most likely to use the humidifier at night, check the noise level that the humidifier makes. It usually creates a bit of white noise which is tolerable but some could be noisy when put in high mist setting. It will help to read customer reviews online to know what customers have to say about the noise and watch video demos to hear it for yourself.

How Filter-Free Humidifiers Work

Filter-free humidifiers basically use the same mechanism as traditional humidifiers, other than they don’t require filters. To give you just a brief overview, humidifiers create mist using water and release them to the air to increase the humidity in the room or the house. Traditional humidifiers require filters so that the air comes out fresh and clean. But for the filter-free models, the mist is produced by micro vibrations and that also purifies the water before the steam is produced.

That is why they are also called Ultrasonic Humidifiers. Most ultrasonic models produce cool mist. But there are also some that create warm mist. To know more about cool mist humidifiers, you can read our guide on the Best Cool Mist Humidifiers, and for warm mist models, you can also read our Best Warm Mist Humidifiers guide.


Filter-free or Ultrasonic humidifiers are absolutely very convenient and they do offer the same performance as that of filtered models. The only disadvantage that is really observable, at least to date, is its weakness when it comes to using hard water because the ultrasonic filter is not as strong.

Further Reading on Best Humidifiers