Here's how to clean your humidifier to keep the air in your home free from bacteria and mold.
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humidifier sitting on a wood surface with sparkles
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Your humidifier can be helpful for keeping your home moist and cozy during cooler winter months. However, unless you're regularly cleaning your humidifier, it can also be a breeding ground for germs and bacteria, which can put your health in danger.

Ryan Donovan, senior category manager of indoor air quality for Ferguson HVAC, says, "Because today's modern homes are so energy efficient, they allow for very little fresh air to get in or stale air to get out. A humidifier is one appliance that can quickly improve your indoor air quality by delivering moisture to the air and maintaining the proper humidity levels." However, a dirty humidifier can aerosolize bacteria or mold and then mist it into the air you breathe.

What Makes a Humidifier Dirty?

A humidifier can get dirty quickly, especially if you fill your humidifier with tap water. "The type and mineral levels in tap water vary based on where you live and your water source but, over time, mineral deposits build up and contaminate the humidifier, producing bacteria," Donovan says.

Additionally, minerals can form fine white dust inside your appliance, breeding more germs, which can accumulate inside the machine's reservoir. Donovan adds, "By design, the humidifier vaporizes the bacteria and fine white dust, and the germs find their way back into the home."

The humidifier's design makes it the perfect environment for bacteria, mold, mildew and other dangerous microbes to multiply and potentially cause harm. "Therefore, the problem from a cleaning perspective is that as you increase humidity indoors using this appliance, you're providing additional nourishment to mold and mildew and creating a breeding ground, where it can feel like an endless battle," he explains.

Plus, living in a home with a dirty humidifier can make you sick. "An excessively moist air environment provides no health benefits and, more importantly, not adequately cleaning and disinfecting a humidifier can create a source of bacterial infection," he says.

This can be especially bad for those with asthma, allergies or other respiratory conditions, since it can be damaging to your lungs. "Simply forgetting to clean your appliance can spread harmful fungi within the home and trigger respiratory problems, sore throats, nasal congestion and even fever," Donovan explains.

Plus, it can reduce your humidifier's lifespan. "The mineral buildup, dust and debris left in the humidifier can significantly affect its wear and tear," he explains. So, be sure to clean your humidifier regularly for better overall health.

How to Clean a Humidifier

You can clean your humidifier with some simple household items—and it only takes a few minutes. Donovan says, "These steps should enable you to maintain your home humidifier better and improve the indoor air quality of your residence."

Since there are many different types of humidifiers, first consult the owner's manual to see what's required, as each model has its own specific care and maintenance requirements. "Plus, a product's warranty is often extended when the appropriate cleaning instructions are followed," he says.

After reading the manual, unplug the humidifier from the wall and disassemble, following the manufacturer's instructions. Remove and empty the water tank and any other parts indicated in your manual.

Vinegar and Water

Donovan says to prepare a cleaning solution with vinegar and water. "Pour white vinegar into the base [of the tank], be sure to fill it with enough vinegar to cover the entire area where regular contact with water occurs, and if you have any smaller items that are dirty, put them inside the base container to soak in vinegar," he says. If they do not fit in the base, immerse them in a bowl of vinegar instead. Allow everything to soak for 30 minutes and then finish off by using a soft brush to scrub away any lingering residue. Then rinse everything off with tap water and reassemble your humidifier.

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Disinfect Your Humidifier

To get rid of any lingering bacteria, you may want to disinfect your humidifier. To do this, "Mix a teaspoon of bleach with a gallon of water and fill the tank halfway or more with the solution, swirling it around the tank until all sides are re-coated with the solution," Donovan says.

Afterward, rinse all the parts with water. "Using tap water, rinse entirely the base, parts and tank and gently shake all the pieces to remove any trapped moisture," he says. If the residue or odors aren't completely removed, gently scrub everything with a soft-bristled brush. Donovan adds, "If your unit has air filters, use this time to run the air filter under cool water until rinsed clean." Leave the air filter out to dry naturally once you're done rinsing it.

Lastly, reassemble the humidifier and piece it back together once all of the components are fully dry. "Don't forget to adjust the air filter if you had to have one of those replaced, and fill your tank with clean, mineral-free water before plugging it in to let it humidify your home," he says.

How Often to Clean Your Humidifier—and How to Maintain It

The Environmental Protection Agency recommends cleaning your humidifier every three days. While that may be hard to keep up with, it can make a real difference in your health and the lifespan of your humidifier.

Before each use, you should also rinse out the basin and replace the water. "This will lower the chance of mold and mildew building up," Donovan says. He recommends opting for distilled water, since it has a lower mineral content. "When minerals are present, they disperse into the air and vapors from the humidifier, which may increase the airborne dust in the rooms with the unit. These minerals can also promote a breeding ground for bacteria," he says.

You should also clean and drain your humidifier for storage during seasons when it's not in use. "After using your humidifier for the season, it's vital to wipe the moisture off of it and then allow it to dry before you pack it away. If there are any crevices within the device when you store it away, you may notice mold when you pull it out of it to use again," Donovan cautions.

Lastly, be wary with use of essential oils, no matter how nice they smell or make you feel. "Essential oils won't dissolve correctly in a humidifier, since humidifiers aren't designed to break down the water and oils into an absorbable solution," he says. So, you might want to reconsider using essential oils in your humidifier and find alternative ways to enjoy their pleasant aromas and qualities instead.