Humidifiers are incredibly beneficial, especially in dry cold weather. They add useful moisture to indoor air, which is vital in preventing many health issues. The additional humidity also helps moisten our sinuses and mucus membranes to prevent health infections further.
Unfortunately, humidifiers also present a few health hazards, with germs and mold being two key risks. Although these two issues are mostly associated with dirty, unmaintained humidifiers, some types of humidifiers are prone to the build-up of both mold and germs, even when regularly cleaned and properly maintained.
You want to steer off these types of humidifiers by picking a model that resists mold and germ growth. Better still, you must learn what needs to be done to prevent mold and germ growth (and spread) when using a humidifier. That’s what this guide is all about.
What Causes Germs and Mold in Humidifiers?
Now that we know about some of the best germ and mold-free humidifiers, let’s discuss what else you need to know about humidifier mold and germs.
There are a couple of factors, from sitting water to the germs in tap water and recirculation of moisture inside the house. Here’s what you need to know;
Tap Water Contains Minerals
The minerals can create deposits inside your humidifier that promote bacterial growth. These minerals include calcium, magnesium, sodium, and much more. They are added to tap water to make the water tasty and healthy, aiding in bodily functions.
However, when you use this water in a humidifier, the minerals are deposited in the tank and humidifier. Over time, this buildup can serve as a breeding ground for germs and mold.
Remember that tap water contains minor traces of certain bacteria. When you use the water in your humidifier, these bacteria will be transferred into the indoor air, creating various health issues, such as difficulty breathing, especially in children.
Sitting Water is Unhealthy Water
The other cause of germs and mold in humidifiers is that humidifier water sometimes sits too long. Sitting water is terrible, even for drinking. Many health organizations advise that you instead use running tap water. And, yes, it’s also bad for your humidifier.
The reason? Bacterial and other microorganisms. The type of stagnation that happens when you let water sit in a humidifier tank for long periods is called trapped water stagnation. Trapped water stagnation creates an excellent incubation ground for many kinds of bacteria.
The worst part is that it takes as little as a few days for bacteria to mature and multiple. The result is that when you next use the humidifier, you’ll be spraying lots of bacteria and other hazardous microorganisms into your home.
(Dirty) Filters are a Health Hazard
Most humidifiers contain filters. The filter plays a central role in ensuring that the moisture that eventually reaches your home is clean and healthy. By trapping any solid particles within the water and eliminating any bacteria and microorganisms in the moisture, they keep your indoor air in the best possible condition.
So, the next question is – where do the trapped particles go? Where do the bacteria and microorganisms from outbound moisture go?
They remain trapped within the filters! Until the filter is thoroughly cleaned or replaced, all the dirt and dangerous microorganisms will still be inside the humidifier. After some time, these filters may also turn into breeding grounds for bacteria and mold.
Can Humidifiers Spread Mold and Germs?
Unfortunately, the answer is – yes. Single room humidifiers and other portable models such as personal humidifiers are especially notorious for spreading germs and mold.
This happens in two ways;
First off, as the humidifier sits in the middle of the room, it can collect significant amounts of germs from the indoor air. This is especially true if you have pets and kids. Ideally, you want to avoid such germs as much as possible. But, the way humidification works is that the moist vapor is pumped at speed into the home to reach every corner of the room.
This action can stir up the dust and germs in your home and mix it with the vapor. So, as you breathe in the humidified air, you also end up inhaling the mold and germs.
The other method usually begins from the sitting water we mentioned above. The longer the water sits inside the humidifier, the greater the risk of mold growth. It could be just a little water left in the unit humidifier last time you drained the tank.
When you next fill up the tank, the mold gets absorbed into the new/freshwater. Some humidifiers have an incredibly reliable filtration system that can trap the mold, so it doesn’t go out together with the mist. But, in many cases, traces of mold will find a way out.
What’s a Germ-Free Humidifier?
Germ-free humidifiers are humidifying appliances designed to improve indoor humidity while minimizing the growth or spread of germs and mold.
They aren’t 100% free of germs. You’re still required to keep the humidifier unit clean and take a few precautions to repress the growth and spread of mold further. But, the humidifiers feature unique technologies to fight both germs and mold, which makes them a safer bet in an environment where these microorganisms aren’t wanted.
The best germ and mold-free humidifiers can be grouped into three categories – ultraviolet humidifiers, humidifiers with antimicrobial silver technology, and steam humidifiers.
- Ultraviolet humidifiers: Also known as just UV humidifiers, ultraviolet humidifiers use a special type of UV light known as germicidal UV. Germicidal UV works by damaging the genetic material of bacteria and viruses. Indeed, devices emitting UV light have been used by hospitals to kill pathogens on surfaces and in the air for years.
- Antimicrobial humidifiers: Antimicrobial silver humidifiers, meanwhile, use silver to attack microorganisms. Silver ions do their work by punching holes into the bacterial membranes and wreaking havoc once inside the organisms. They bind to DNA cells, making it impossible for the microorganisms to perform their most basic functions.
- Steam humidifiers: Finally, steam humidifiers don’t use any special technology. Instead, they rely on heating to kill any living organism within the water. The water is heated in a reservoir until it evaporates into steam and the steam released into the home. By the time water evaporates into vapor, most organisms are usually dead.
Benefits of Germ-Free Humidifier
There are several reasons you need to do everything you can to prevent the development or spread of mold and germs during the humidification process.
- Minimize allergies and asthma attacks: If you or someone in the family has allergy or asthma, regularly inhaling airborne germs and mold can aggravate the symptoms or cause a full-on attack.
- Prevent asthma: It may sound that we’re repeating the first point, but no, we’re not. Mold can not only aggravate an asthma attack; it may also cause it. According to a 2018 paper in the European Respiratory Review, people exposed to mold for extended periods are at a high risk of developing asthma.
- Prevent humidifier lung: Worse still, the germs and mold can cause what’s known as humidifier lung, a type of respiratory illness. Humidifier lungs is characterized by coughs, fever, chills, shortness of breath, and body aches.
- Prevent airway inflammation: Airborne mold can also cause throat inflammation. You’ll know you have an airway infection when you have an itchy throat. If left unchecked, airway inflammation can lead to more serious respiratory illnesses.
How to Prevent Germs and Mold in a Humidifier
As already mentioned, it’s impossible to 100% eliminate germs and mold in indoor air. Even the best humidifiers only promise 99.9% efficiency. However, there are steps you can take to drastically minimize the presence of these microorganisms as you humidify the home;
Buy a germ and mold-free humidifier
We’ve already looked at the three main categories of germ-free humidifiers – ultraviolet, antimicrobial, and steam. Any of these would prove very useful in minimizing the development and spread of germs and mold during the humidification process.
Follow best practices
The way you use your humidifier also matters a lot in whether you’re attacked by mold/germs or not. The following are a few safe-use tips to consider;
Use distilled or demineralized water
As we saw earlier in the guide, tap water contains several minerals usually added to the water to make it healthier and tastier. When used in humidifiers, the minerals in such water can cause buildup, providing an excellent building ground for germs and bacteria.
Therefore, you’re advised to avoid using tap water for humidification altogether. Instead, use distilled water. Alternatively, if you must use tap water, make sure to demineralize it first.
Change the humidifier water often
Something else that’s very important is changing the water regularly. Leaving water inside the humidifier tanks for long periods, say a few days, creates the perfect environment for the growth and replication of mold and bacteria.
To prevent this problem, change the water often. Most experts recommend that you pour out the old water and refill the unit with new water every day. Make sure to rinse the tank before adding fresh water.
Change the humidifier filter regularly
How often you need to change the filter will depend on the filter type and level of use. For standard filters, you’re advised to change the filter at least once every three (3) months, or every two months if you use the humidifier daily.
However, if your humidifier contains a mineral absorption pad, consider replacing the filter every two to three weeks to prevent mineral deposits from being emitted.
At the same time, a few special filters are designed to be washable and reusable. For this case, you need first to check to confirm that your filter is washable and reusable.
Once you’re sure that you can reuse it, make sure to wash the filter every month to prevent dirt buildup. Above all, remember that even washable filters need to be replaced at some point. Follow the manufacturer’s guidelines on both washing and replacement.
Change the wick regularly
Not all humidifiers use wicks. So, the first step here is to determine whether your model uses one. Mostly, you’ll find the wick in evaporative humidifiers. These wicks aren’t designed to serve you forever. Over time, they become packed with sediments extracted from the water, which can comprise their efficiency and function. At that point, replacement becomes necessary.
The good news is that you don’t need to replace the wick as often as the filter. Instead, you only need to change the wick once every humidification season or twice per humidification season if you use hard water in the humidifier.
Clean the humidifier regularly
Finally, to prevent or minimize mold, you also need to regularly clean the humidifier according to the manufacturers’ recommendations.
Why and How to Clean a Humidifier
There are several reasons why you need to clean your humidifier regularly. For one, cleaning the unit regularly increases the effectiveness and efficiency of the humidification process. Secondly, cleaning helps remove the mold, germs, and other microorganisms that we’ve discussed throughout this article. These microorganisms are a health risk. Also, regular cleaning extends the life of the unit.
For the cleaning process, you’ll need;
- White vinegar
- Bleach or hydrogen peroxide
- Plenty of water
- A soft-bristle brush
- Clean gloves and goggles
- Clean towels
Once you have the above items, proceed as follows;
- Turn off the humidifier and unplug it from the electrical supply
- Disassemble the humidifier completely. Remove the filter
- Remove and empty the water tank
- Pour white vinegar into the base and allow to sit for 30 minutes
- As you wait for the base to soak, half-fill the tank with water, add one teaspoonful of bleach, and swirl. Then let it settle for 30 minutes too.
- Use the soft brush to scrub the now-soaked base
- Use warm water to rinse the base, tank, and other components thoroughly.
- Lay all the parts out to dry
- Reassemble the unit without forgetting about the filter
- You’re now ready to fill the tank with water and use the humidifier again
Mistakes to Avoid When Using Humidifiers
As a final point, sometimes people make a few mistakes that may contribute to ineffective humidification. These mistakes may even compromise germ and mold prevention. You need to be observant enough to avoid these mistakes. They include;
- Ignoring humidity levels in the home
- Letting humidity levels rise too high
- Failing to clean the humidifier often enough
- Using tap water in your humidifier
- Letting water sit in the humidifier tank
Best Germ Free Humidifier Reviews
Let’s begin by rounding up some of the best germ and mold-free humidifiers. As already mentioned, all humidifiers are likely to develop mold and germs when they get dirty.
The models listed here are specifically designed to resist as much as possible the growth of these microorganisms for cleaner, healthier indoor air.
1. Honeywell HCM350W Germ-Free Cool Mist Humidifier
- CLEANER INVISIBLE MOISTURE – Honeywell Cool Moisture Humidifier effectively brings invisible moisture to your home. It utilizes UV technology and a wicking filter to help treat the water and capture minerals to keep them out of the air for a cleaner mist.
- EVERYDAY COMFORT – This humidifier for home features evaporative technology that increases and holds the targeted humidity level to optimize moisture in the room. It’s ideal for everyday comfort and year-round relief from dry throat and dry, itchy skin.
- EASY TO USE – Featuring a large 1.1 gallon, easy-fill, self-standing tank, this cool moisture humidifier provides up to 24 hours of run time. Plus, it’s easy to clean – all parts that touch water can be cleaned in the dishwasher.
- HUMIDIFIER FOR BEDROOM – As the ideal humidifier for baby, this device has a soft, fan-like sound to add restful noise to any room. Great for an adult or child’s bedroom, the large tank can run overnight, providing consistent soothing moisture.
- COMPATIBLE DOES NOT MEAN COMPARABLE – For best performance, use only a genuine Honeywell Replacement Wicking Filter A. Compatible humidifier filter replacements are not guaranteed to offer the same performance or efficiency.
The Honeywell HCM350W is an evaporative cool mist humidifier that uses a 1-gallon tank to add cool moisture to the indoor air gently.
The tank is enough to sustain you for 24 hours, while the humidifying rate is designed to keep your indoors in the 40-60% humidity levels for improved breathing and sleeping and to reduce nasal congestion.
Several features make the HCM350W the ideal germ-free humidifier. For one, it utilizes incredibly effective UV technology. When you fill the unit with water, the water flows through a UV water path where it’s exposed to ultraviolet light. UV light kills 99.9% of bacteria, mold, fungi, and viruses. Secondly, it uses a filter to trap any particles in the water, thus only sends clean, healthy air into your rooms.
The unit also comes with a Protec cleaning ball to keep your humidifier cleaner for longer and uses replacement filters specially treated with Protec antimicrobial chemicals.
- Inexpensive (at under $70)
- UV technology kills 99.9% of germs
- Easy to fill, carry, clean
- Comes with a Honeywell humidity monitor
- The small tank is best for smaller rooms
2. Levoit LV600HH Warm and Cool Mist Ultrasonic Humidifier
- 𝙃𝙄𝙂𝙃-𝙀𝙁𝙁𝙄𝘾𝙄𝙀𝙉𝘾𝙔, 𝙁𝙊𝙍 𝙒𝙃𝙊𝙇𝙀 𝙃𝙊𝙈𝙀: It provides humidification speeds 4× faster than others, which can quickly cover 753ft² of the area and last up to 50 hours. You can customize the target humidity you need, and feel hands-free with auto mode.
- 𝙋𝘼𝙏𝙀𝙉𝙏 𝙒𝘼𝙍𝙈 𝙈𝙄𝙎𝙏 𝙏𝙀𝘾𝙃 𝙁𝙊𝙍 𝘽𝙀𝘿𝙍𝙊𝙊𝙈: It raises RH 10% in 20mins, providing greater relief from symptoms caused by dir air. Near-silent noise levels and all lights off help you sleep undisturbed
- 𝙋𝙀𝙍𝙁𝙀𝘾𝙏 𝙁𝙊𝙍 𝙇𝘼𝙍𝙂𝙀 𝙍𝙊𝙊𝙈𝙎: With a mist output of up to 500 mL/hr, it can easily handle spaces as large as 753 ft² / 70 m². The large 6-liter tank allows you to humidify continuously for up to 50 hours, saving you the trouble of frequent refills
- 𝘼𝙐𝙏𝙊𝙈𝘼𝙏𝙄𝘾 𝙏𝙐𝙍𝙉 𝙊𝙉 & 𝙊𝙁𝙁: With a built-in sensor, Auto Mode adjusts mist levels according to your settings to maintain a healthy humidity level
- 𝙃𝙐𝙈𝙄𝘿𝙄𝙏𝙔 𝙐𝙋 𝙏𝙊 𝙔𝙊𝙐: You can customize the ideal humidity percentage for your house plant, baby, or beloved guitar
- 𝙍𝙀𝙇𝘼𝙓𝙄𝙉𝙂 𝘼𝙍𝙊𝙈𝘼𝙏𝙃𝙀𝙍𝘼𝙋𝙔: Add your favorite essential oils to the aroma box and enjoy wonderful, fresh-smelling air
- 𝘾𝙊𝙉𝙑𝙀𝙉𝙄𝙀𝙉𝙏 𝙍𝙀𝙈𝙊𝙏𝙀𝙍 𝘾𝙊𝙉𝙏𝙍𝙊𝙇: Already in bed and don't want to get up? The convenient remoter control lets you quickly turn on the humidifier from across the room whenever you need
- 𝘼𝘽𝙎𝙊𝙍𝙋𝙏𝙄𝙊𝙉 𝙋𝘼𝘿𝙎 𝙍𝙀𝙋𝙇𝘼𝘾𝙀𝙈𝙀𝙉𝙏: Please search Levoit absorption pads which can prevent stubborn mineral buildup on the heating plate of the humidifier
- 𝘼𝙍𝙊𝙈𝘼 𝙋𝘼𝘿𝙎 𝙍𝙀𝙋𝙇𝘼𝘾𝙀𝙈𝙀𝙉𝙏: Please search Levoit aroma pads for more information which can help emit a stronger fragrance and protect the fragrance box.
Many humidifiers are usually either warm mist or cool mist. If you want the flexibility to switch through the cool and warm options as you wish without breaking the bank, this Levoit hybrid unit would be a superb acquisition. For bacteria-free humidification, we recommend that you set it to the warm mist setting.
It’s also the largest humidifier on this list at six liters, making it ideal for large rooms. The manufacturer says it’s effective in rooms as large as 753 square feet.
In total, it allows for 60 continuous hours of use at the low mist level. You can set the mist levels on your own. Alternatively, you can set the unit to run on Auto Mode in which the in-built humidity sensor adjusts the mist level automatically.
The LV600HH is remote-controlled and even has a 1-12-hour timer. It’s also the quietest whole house humidifier and comes with aroma pads, absorption pads. And a cleaning brush.
- Warm/cool-mist hybrid
- Large capacity humidifier
- Ultra-quiet operation
- Convenient remote control
- Easy to clean
- No UV light protection
- No antimicrobial silver protection
3. Vicks V3900 Germ-Free Cool Mist Humidifier
- VICKS COOL MOISTURE HUMIDIFIER: This quiet, cool moisture humidifier for bedrooms & other large rooms
- VICKS HUMIDIFIERS FOR KIDS, ADULTS: This cool mist humidifier helps add moisture into the air. Many women & men find that a humidifier for the bedroom becomes an essential part of a good night's sleep when the air is dry, in season, or when sick.
- COUGH & CONGESTION RELIEF: When you or your kid has a cold, it can be difficult to sleep through the night. Humidifiers and vaporizers provide temporary relief from coughing and congestion, so your rest won't be as disturbed by coughing fits.Automatic Moisture Balance System
- VICKS VAPORIZERS, HUMIDIFIERS, & STEAM INHALERS: Steam & humidity offer temporary relief from cough & congestion. Vicks humidifiers & steam inhalers can help you breathe easier wherever you are, from the bedroom to office.
- HUMIDIFIERS FOR BEDROOMS, DESKS,TABLES: Our humidifiers & vaporizers help you breathe better wherever you are.
This is another cool mist humidifier. It uses special Vicks VapoPads to deliver soothing, aromatic vapors, each pad designed to last up to eight hours. It’s also an evaporative humidifier meaning that it utilizes a wick filter to break down water particles into tiny mist particles.
Several steps are taken to make the V3900 germ and mold-free. For one, the wicking filter is a Genuine Protec filter. The filters are antimicrobial treated to inhibit up to 99.9% of mold, algae, and bacterial growth. They also remove minerals and pollutants from the water. Secondly, it uses UV technology to kill the remaining traces of bacteria.
The one-gallon humidifier keeps indoor humidity levels between 40% and 60%, is ETL approved, and is backed by a 3-year warranty.
- UV protection
- Genuine Protec filters
- Filters are antimicrobial treated
- 3-year warranty
- Small, one-gallon tank
- Only runs for 24 hours
4. Health Smart Mist XP Model 40-685-000 Cool Ultrasonic Humidifier
- RELIEF FOR DRY SKIN, THROAT IRRITATION, COUGHS AND CONGESTION. The Mist XP humidifier will add much-needed moisture to the air on dry days, keeping your skin moisturized, helping you breathe easier and reducing static electricity. Don’t let low levels of humidity slow you down.
- RUNS UP TO 24 HOURS! It has a 0.66 gallon capacity, meaning you won’t have to spend time refilling it. No need to take time to monitor it.
- COOL, QUIET MIST. Safe ultrasonic cool mist technology means you do not have to monitor who touches it. Control the perfect amount of mist with the adjustable mist knob. It’s whisper quiet and will not disturb or distract you during your busy day or restful night. It also won’t distract you while you work!
- FILTER FREE You won’t have to purchase costly filters or wicks or spend time replacing them.
The Model 40-685-000 Mist XP humidifier from Health Mist is also a cool-mist humidifier. But it’s not evaporative. Instead, it’s ultrasonic, meaning that it breaks down water particles into fine mist using ultrasonic sound vibrations.
Two essential qualities that make the unit another excellent choice for germ and mold-free humidification include the filter-free humidifier design and antimicrobial tank.
Filters can form a breeding ground for mold and bacteria. The filter-free design removes this risk. The antimicrobial treatment further protects the tank from the growth of harmful germs.
Other key features of the Mist XP include the sleek, styling design and whisper-quiet operation. It also features adjustable mist dials and is backed by a 3-year manufacturer warranty.
- Sleek and stylish design
- Cool, quiet, mist
- Convenient, filter-free design
- Antimicrobial water tank
- 3-year warranty
- Small, 1-gallon tank
- Runs for only 24 hours
5. BONECO Digital Steam Humidifier S450
Finally, the BONECO S450 is the only steam humidifier on this list. Steam humidifiers are known to be healthiest because the heating process kills virtually all microorganisms in the water. Heating also helps to break down the minerals in tap water into harmless particles.
But, the S450 doesn’t stop there. It also features an auto-cleaning mode that automatically cleans and decalcifies the inside of the unit. Additionally, it utilizes safe anti-mineral pads to minimize calcification, EZCal cleaner and descaler to clean mineral buildup, and EZCal Pro cleaner for mid-season deep cleans.
Other key features of the unit include intelligent controls, such as the auto-mist technology and econ-mode for environment-friendly operation. An integrated hygrostat, an on/off timer, and maintenance reminders are also present.
- Healthy steam humidification
- Bacteria and mineral-free humidification
- Ideal for large rooms, up to 860 square feet
- Self-cleaning and auto descaling
- 3-year manufacturer warranty
- Most expensive on this list (at over $250)
Germ and mold-free humidification is possible. But you must be willing to work hard to achieve it. You need to buy the right (germ & mold-suppressing) humidifier, use it properly, clean it regularly, and change the wick and filter, as recommended by the manufacturer.
Most importantly, don’t forget to replace the humidifier when the time comes. An old, outdated humidifier is an unreliable, unhealthy humidifier.