How to Properly Clean a Humidifier

When the weather gets colder, you might not notice that the air in your home is drier than usual. However, you could very well experience the effects: chapped lips, dry skin, itchy eyes, and a host of other respiratory symptoms. A humidifier can help combat the effects of dry air by producing water vapor and increasing the humidity in your home. Unfortunately, without proper cleaning and maintenance, a humidifier can also increase the airborne pollutants that you and your family members breathe in every day. Below, we take a look at the best ways to keep your humidifier working safely and properly so that you can enjoy the benefits without worrying about releasing mold and bacteria into the air.

Cleaning the different types of humidifiers

The U.S. Consumer Product Safety Commission (CPSC) and the Association of Home Appliance Manufacturers (AHAM) recommend cleaning any new humidifier before the first use and then cleaning it regularly during the life of the product. Even if you are unsure of what type of humidifier you have, most have similar cleaning instructions. Below, we’ll list the major types of humidifiers and what you should note when beginning the cleaning process. All humidifiers do the same thing: introduce moisture into the air. But the method in which they do this differs by product type. Though it may go without saying, make sure to unplug the unit before cleaning.

Different types of humidifiers

  1. Ultrasonic humidifier: Designed for use in a single room, these humidifiers use ultrasonic vibrations to create both cool and warm mist. Note that for ultrasonic types of humidifiers, mineral deposits can appear more frequently if you have hard water at home so you should check the reservoir before use.
  2. Warm mist humidifier: Probably the most well-known type of humidifier, warm mist models use a heating element to vaporize water. The resulting steam is then cooled down before it is introduced into the air. These humidifiers come in different sizes and can potentially be used for multiple rooms.
  3. Evaporator: These humidifiers involve a filter attached to a tank of water. A fan blows air through the filter to release water vapor into the air. Like warm mist humidifiers, evaporators can come in different sizes intended for use in a single room or multiple rooms. If you are using an evaporator, it may be easier to replace the filter than clean it. Your instruction manual will give you specific instructions for your type of filter.
  4. Impeller humidifier (also called a “cool mist” humidifier): Impeller humidifiers use rapidly rotating disks to produce a cool mist that is released into the air. Impeller humidifiers are typically for single-room use only. Note that you should use low-mineral content water or bottled water when using this type, to prevent buildup of “scale”, or crusty deposits, inside the humidifier. Most importantly, avoiding the use of tap water will ultimately help minimize the deposit of minerals into the air.

Though the inner workings of the above humidifiers can be very different, most contain a water tank and an operating base through which the water travels before being released into the air. Any additional components should be able to be detached and cleaned. Remember, your humidifier should always be turned off and unplugged before you start cleaning it. Never let any water or cleaning solution get into the humidifier’s electrical components.

General cleaning tips for all types of humidifiers

The CPSC recommends the following cleaning practices for humidifiers that hold less than five gallons of water:

  • Clean the unit daily. This includes emptying all leftover water, wiping all of the component’s surfaces with a towel, and refilling the humidifier with clean water.
  • Sanitize the unit once a week. First, empty any leftover water from the humidifier. Then, fill the water tank with a weak bleach solution (around one teaspoon of bleach for every gallon of water). Leave the bleach solution in the water tank for around 20 minutes, swirling it around every few minutes to make sure that the sides of the water tank are coated. Next, pour out the bleach solution and rinse the tank with water until you cannot smell the bleach anymore. (Note: The EPA states that you can also use a 3% solution of hydrogen peroxide in place of a bleach solution.)
  • Remove scale and mineral deposits after sanitizing. You can do this by creating a vinegar solution (one cup of vinegar per cup of water) and using it with a soft brush or towel to remove any visible mineral buildup.

Cleaning specific humidifier brands

Though the above guidelines provide a general idea of how to properly maintain your humidifier, you will usually get the best results by following the manufacturer’s instructions. Different brands of humidifiers may be composed of different materials that require specific cleaning protocols. If you no longer have your owner’s manual, you can typically find a copy of it on the manufacturer’s website. Below, we discuss the cleaning guidelines for popular units from three of the top humidifier brands (and note that although you may have a different model than those listed here, cleaning recommendations are likely very similar across humidifiers from the same brand).

  1. Vicks SweetDreams Cool Mist Humidifier: This humidifier should be cleaned weekly. First, in order to remove the scale, take out the water tank from the base and empty all water from both parts. Add two cups of undiluted, distilled white vinegar to the water tank and swish it around. Then, put the tank back on the base and allow the vinegar to drain into the water reservoir. Let the vinegar sit for 15–20 minutes before pouring it out. Wipe all of the components with a soft cloth to remove mineral deposits. Next, pour one cup of water into the reservoir and swish around before pouring out. Repeat the last step until you can no longer smell the vinegar. The manufacturer recommends disinfecting the humidifier once a week as well, by performing the above process using a solution of ½ teaspoon of bleach and ½ gallon of water. The two cleaning processes must be done completely separately.
  2. Honeywell HE360 Powered Flow-Through Humidifier: Every one to three months, depending on your water quality, take the humidifier apart for cleaning. After removing the humidifier pad and water nozzle, wipe away all visible mineral deposits on any of the humidifier’s components. Then, clean the drain hose with pressurized water before reassembling the unit.
  3. Crane DROP SHAPE Ultrasonic Cool Mist Humidifier: Empty water from the unit every day and let it air dry. Once a week, fill the tank halfway with water and add two teaspoons of white vinegar. Shake the solution around the tank, then let it sit for 30 minutes before rinsing it out with water. Then, fill the base with warm water and add one teaspoon of white vinegar. Let sit for thirty minutes before rinsing with water. Wipe off the nebulizer with a cloth or cotton swab after soaking. Lastly, leave the top off of the tank and let the components air dry until the next time that you use the unit.

As you can see, the cleaning guidelines can differ significantly depending on the humidifier’s brand. This is why we recommend checking the manufacturer’s instructions before using any cleaning solution on your humidifier.

General humidifier maintenance tips

Aside from cleaning your humidifier regularly, there are a few general use tips that can help ensure that you keep your unit working safely and effectively.

  • Never let the area around your humidifier become wet or damp. This is a sign that the humidifier output needs to be turned down.
  • Make sure that your humidifier does not make the relative humidity in your home over 50%. Too much moisture in the air can promote mold and mildew growth.
  • Try to use water with low mineral content. This can help reduce mineral buildup on your humidifier. Some manufacturers recommend using distilled water instead of tap water.
  • Clean and sanitize your humidifier thoroughly at the start and end of every humidifier season (if you only use your unit during the colder months).

Why cleaning your humidifier is essential for your health

A humidifier may improve the air quality in your home, but only if you care for it properly. Because of the water (and, typically, heat) present in home humidifiers, they can become a breeding ground for bacteria and fungi. The CPSC warns that these pollutants can be released in the mist produced by your humidifier. When inhaled, the contaminated mist can cause a wide range of health problems, from flu-like symptoms to dangerous infections.

Additionally, any minerals present in the mist can settle on the surfaces in your home as fine white dust. This dust can contain particulate matter small enough to be inhaled, which can cause health effects such as increased respiratory symptoms, as well as heart and lung damage. Individuals with asthma and allergies are more vulnerable to the dangers of a dirty humidifier.

Though an air purifier like Molekule can remove airborne mold spores and bacteria from your home, the best way to maintain your indoor air quality is to prevent your humidifier from releasing pollutants in the first place. Signs that your humidifier contains bacteria or fungi include:

  • A layer of film or scum on the water surface or interior surfaces of the tank.
  • A flaky scale on the tank or other humidifier components.

Like most people, you probably bought (or are thinking of purchasing) a humidifier for your home to find relief from the unpleasant effects of dry air. By taking care to clean your humidifier regularly, you can extend the life of your unit and protect the health of yourself and your family as well.