When your allergies flare up, you might want to be proactive to find ways to improve your indoor air quality. Maybe it is allergy season. Maybe indoor allergens are to blame. One way to ease allergies may be to use a humidifier, but humidifiers have their pros and cons. Could it help with your allergies? Let us find out:
Will a humidifier help my allergies?
Humidifiers increase the relative humidity in the air. This increase in moisture may help with your allergies. It may make them seem less severe if dry air has irritated your nasal passageways. However, excess humidity above 50% could make conditions worse. Indoor allergens like dust mites and mold thrive in moist conditions.
At an acceptable level, humidity may help in a number of ways:
- A humidity level above 30% can help keep your nose and throat from drying out, according to the National Asthma Council of Australia. The dry, cracked skin inside your nose or throat that results from dry air can make every breath feel raw and uncomfortable, even if you do not have allergies at all. The sneezing and sniffling of an allergy attack feels even worse in dry conditions. Humidified air (and drinking plenty of water so you stay hydrated) may help keep your nose and throat from drying out.
- It can help your body maintain its defense systems. Proper humidity levels (and, again, hydration) help your body create a healthy mucus layer in your nose and throat. Fisher & Paykel Healthcare describes it this way: That mucus layer traps contaminants as you inhale them, preventing them from getting into your respiratory system and triggering an allergic reaction or causing colds, sinus infections and the flu. The tiny hairs, called cilia, at the back of your nose and lining your airways are also part of this defense system, and they too work best if you are not too dried out (Bustamante-Marin & Ostrowski, 2017).
- It reduces the number of particles in the air. Studies have found that moderate humidity levels decrease the number of airborne pathogens, because water vapor tends to condense on particles in the air, and the resulting water droplet will settle out of the air if it is heavy enough, removing the pathogen from the air. More moisture means this happens more often. Hospitals kept between 40 and 60 percent humidity were found to have a lower rate or infectious disease than those with extremely low relative humidity (Taylor & Hugentobler). It is conceivable, although no studies have been conducted, that this same effect could reduce the number of allergens in the air.
Potential problems with humidifiers and allergies
Using a humidifier to relieve your allergy symptoms is not a perfect solution. There are some potential problems associated with humidifier use that you need to watch out for.
A humidifier that is used improperly can raise humidity levels too, creating damp air or even causing moisture to condense out of the air onto surfaces in the room. A damp rug or wet drywall will become moldy. Mold releases mold spores, which can trigger allergic reactions in many allergy sufferers.
To prevent this, make sure you use a humidifier with a humidistat that automatically shuts down at the desired humidity level. The consequences of excessive humidity far outweigh the benefits of a humidifier if you are not careful.
A humidifier that is not properly cleaned can grow mold or bacteria, essentially becoming a mold and bacteria sprayer that contaminates your air whenever it runs. Humidifiers should be emptied, wiped down, and allowed to dry every day, and cleaned with a 3 percent hydrogen peroxide solution every three days, according to the EPA. Ultrasonic humidifiers should only be used with distilled water, since they can contaminate the air with aerosolized mineral particles if they are used with tap water.
One of the most significant household allergen sources, dust mites, are known to die off at humidity levels below 40 percent (“Humidity and Dust Mite Allergies,” Indoor Environment Group of the Lawrence Berkeley National Laboratory). That means that if you primarily suffer from dust mite allergies, not humidifying your house when it gets dry could improve your allergies. Of course, there are other problems associated with excessively dry air, so it will depend on how severe your dust mite allergies are if it is worth it to trade allergies for dry, scratchy nose and throat.
Types of humidifiers
There are two main types of humidifiers, evaporative and ultrasonic.
Evaporative humidifiers turn water into water vapor by either blowing a fan across a wick that is saturated with water, or by simply boiling the water into steam. Steam humidifiers can be potentially dangerous, especially if used in a child’s room, since they do create boiling water.
Ultrasonic humidifiers use an impeller or diaphragm that vibrates at a very high (ultrasonic) frequency. This propels tiny water droplets into the air. Some of these droplets eventually evaporate, although some settle out onto nearby surfaces. The exact ratio depends on the air temperature and relative humidity in the room. If the water in an ultrasonic humidifier has minerals in it, as most tap water does, aerosolized mineral particles can contaminate the air, leaving a white powder on surfaces once it settles out, and potentially causing respiratory problems if inhaled.
You can also choose between portable single-room humidifiers and whole house humidifiers. A whole house humidifier is attached to your home’s HVAC system and introduces moisture to the HVAC airflow. This has the benefit of humidifying the air throughout your entire house. However, they are more complicated and expensive than portable humidifiers.
A portable humidifier allows you to humidify a single room, and no modifications to your HVAC system are required. They do require maintenance, since they must be kept clean to avoid fungal or bacterial contamination. If you only need to humidify a specific room in your house, rather than the entire house, this is usually a better option.
Which humidifier should you use?
If you are not sure which type of humidifier is right for you, a portable evaporative humidifier is a good place to start. They are relatively inexpensive, and you can run it in your living room during the day and in the bedroom at night. A few weeks of use will let you observe the effect it has on the humidity in your house and on any respiratory problems you might be having.
Be sure you are comfortable with the drying and cleaning required of a portable humidifier, however. Avoiding contamination by fungus or bacteria is extremely important.
How to improve air quality and reduce allergy symptoms
Taking a few basic steps can improve the indoor air quality in your home and reduce the frequency and severity of allergy flare-ups.
- Keep it clean. Vacuum carpets, rugs and upholstery. Wipe down hard surfaces with a damp cloth. Allergens in the air eventually settle, and cleaning removes them from your house. If you do not clean, eventually they will get kicked back up into the air again. A vacuum cleaner with a HEPA filter will do a better job of trapping allergens and other particles.
- Keep the windows closed. If you suffer from seasonal allergies, keep your windows closed and turn on the air-conditioning when your allergies are at their worst. We usually suggest opening windows, because fresh outdoor air is almost always cleaner than indoor air, but in this case you want to keep pollen outside.
- Use an air purification system. This could include a filter on your HVAC system or a portable air purifier.
Using a humidifier in the dry winter months is a good idea, as it will keep your skin, nose and throat from becoming dry and cracked. It will also ease some of your allergy symptoms. It is very important to use the humidifier correctly, however, keeping humidity levels between 40 and 60 percent, and cleaning the humidifier regularly to avoid contamination.
