Humidifiers are incredibly beneficial, especially in the 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.
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.
- Honeywell HCM350W Germ-Free Cool Mist Humidifier
- Inexpensive (at under $70)
- UV technology kills 99.9% of germs
- Easy to fill, carry, clean
- Comes with Honeywell humidity monitor
- The small tank is best for smaller rooms
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 the 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.
- Levoit LV600HH Warm and Cool Mist Ultrasonic Humidifier
- Warm/cool-mist hybrid
- Large capacity humidifier
- Ultra-quiet operation
- Convenient remote control
- Easy to clean
- No UV light protection
- No antimicrobial silver protection
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 a very quiet humidifier and comes with aroma pads, absorption pads. And a cleaning brush.
- Vicks V3900 Germ-Free Cool Mist Humidifier
- UV protection
- Genuine Protec filters
- Filters are antimicrobial treated
- 3-year warranty
- Small, one-gallon tank
- Only runs for 24 hours
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.
- Health Smart Mist XP Model 40-685-000 Cool Ultrasonic Humidifier
- 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
The Model 40-685-000 Mist XP humidifier form 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 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.
- BONECO Digital Steam Humidifier S450
- 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)
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.
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.
What Causes Germs and Mold in Humidifiers?
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 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 your 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/tap water.
- 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
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.