Benefits of Humidification in the Home

Dry air can lead to a host of problems, especially for allergy and asthma sufferers. Dry climates, winter air, and artificial heat all contribute to the discomfort caused by dry skin, dry throats, and irritated noses (which can lead to sinusitis). Winter is an especially bad time for dry air: home heating systems, especially forced-air systems, often reduce the amount of moisture in the air, leading to a home environment that is dry. The Mayo Clinic suggests several steps for combating the effects of dry air:

• Drink more fluids. Water, juice, low-fat milk, and other caffeine-free drinks all help your body to counteract the effect of dry surroundings. Soups and broths are also a good choice, and will also help keep you warm.
• Shorter showers and baths in warm rather than hot water are easier on your skin. Mild soap is best. Showering less frequently will also help guard against excessively dry skin.
• Moisturizing after showers or baths also goes a long way to help prevent dry skin. Apply hypoallergenic lotion while your skin is still slightly damp to help your body absorb the moisturizer and increase its effectiveness. Use lip balm to prevent or soothe chapped lips.
• Saline sprays, which are safe to use regularly, help to combat dry nasal passages.
• Humidifiers provide a great environmental solution to the problem of dry air.

Dry air doesn't only affect the people who live in it, though. Dry air can also damage furniture, wood floors, and paint in your home. A humidifier not only helps those in your home breathe better, but it also helps maintain the air in your home at a comfortable level for everything inside it. Furthermore, air that's too dry makes the temperature feel colder than it actually is; humidification works in conjunction with heating devices to keep you snug and warm during the winter (and save you money on your heating bills).

How Humidifiers Work

There are so many types of humidifiers out there that a decision about which humidifier to purchase can be overwhelming. As when purchasing any appliance, it's helpful to learn how a humidifier works and what's involved in the differences between them.

Humidifiers do what their name suggests – they add moisture to the air. Some homes are equipped with humidifiers that are connected to their overall HVAC systems, but portable humidifiers are quite popular and extremely effective. Following is a breakdown of the overall types of humidifiers, along with their benefits and disadvantages:

• Steam or Warm Mist Humidifiers: These humidifiers boil water and then release the steam into the air of the room. The technology is simple, and steam humidifiers are the least expensive types. Inhalant medications may also be added to this type of humidifier for those suffering from coughing. The drawbacks of steam humidifiers, however, are that they incur higher energy costs than other types of humidifiers, and that the steam could be a hazard to young children.
• Ultrasonic Humidifiers: A vibrating disk operating at an ultrasonic frequency creates water droplets that are then released into the air. The fog that an ultrasonic humidifier produces is cool. Although energy costs for running ultrasonic humidifiers is low, there are still two possible disadvantages related to them – mineral dust caused by using water with a lot of minerals in it and the presence of stagnant water that can breed bacteria. There are ways to counteract these disadvantages, however. (See suggestions in the next section.)
• Impeller Humidifiers: Like ultrasonic humidifiers, impeller humidifiers create a cool fog. A rotating disc throws water into a diffuser, which breaks the water into tiny droplets that then float into the air. Like the ultrasonic variety, impeller humidifiers are subject to the same concerns of mineral dust and bacteria.
• Wick/Evaporative Humidifiers: In this humidifier, some type of wick (made of paper, cloth, or foam) draws water from a reservoir filled with water. A fan that blows above the wick helps the surrounding air absorb the moisture from the wick. Hence, this system is self-regulating because a higher humidity means less absorption and vice versa. The fan in these humidifiers can be loud, however, and, again, stagnant water poses a bacterial threat.

See the Humidifier Buying Guide for more information about different types of humidifiers.

Hygienic Humidification

As demonstrated above, choosing the right humidifier can be a tricky business. The good news is that the potential concerns raised by some types of humidifiers can be easily addressed. For instance, although humidifiers with water reservoirs can breed bacteria and then release it into the air in airborne form, adequate knowledge about your humidifying unit coupled with proper maintenance prevents this from happening.

To guard against both bacteria and mold, some units boil their water before they release it into the air (as in steam humidifiers and warm mist humidifiers). Other humidifying units have added features such as a UV light or an ionic silver stick (ISS). The Slant / Fin GF-220 Humidifier with UV Light and the Enviracaire Germ Free Humidifier both feature a dual germicidal process that has a UV component and a second water chamber that boils the water just before mist is released into the air. The Air-O-Swiss 2055 Air Washer and Humidifier uses an ISS to eliminate bacteria and viruses. The Air-O-Swiss AOS7135 Ultrasonic Antimicrobial Humidifier also uses an ISS, as well as heated water to destroy microbes. In addition, the ultrasonic vibrations themselves destroy much of the bacteria. Germ Guardian Ultrasonic Humidifiers use Silver Clean technology to fight bacteria and mold from forming in the water tank.

Mineral dust is another possible concern. When water with a high mineral content is used in a humidifier, the minerals are released into the air and settle on surrounding surfaces, forming a white dust, or they are inhaled. Using distilled water in your humidifier prevents this. In addition, some humidifiers, like the Air-O-Swiss AOS7135 Ultrasonic Humidifier, have demineralization cartridges to help against white dust.

No matter what type of humidifier you choose, even if it has several built-in microbial features in place, it is very important that the unit be cleaned regularly. Be sure to read the cleaning instructions that come with your humidifier and follow them diligently.

Save Money on Heating Bills with Humidification

Keeping your home's humidity at ideal levels will also help you feel warmer. Low humidity makes the air feel colder because the warmer the air is, the more water it can hold; put another way, the more water in the air, the warmer the air feels. This phenomenon can be understood by considering how high levels of humidity in the summer make it feel hotter than it actually is: when the air is saturated with moisture, the sweat on our bodies does not evaporate, making us sticky and uncomfortable. But winter's low humidity has the opposite effect – dry air causes moisture to evaporate from our skin and we feel cooler.

By making sure that humidity levels are high enough we slow down our bodies' cooling mechanism, which we obviously don't need in the cold winter time. The upshot of all this is that a humidifier can save you a lot on your heating bills. Naturally, if you feel warmer even if the temperature remains the same, you won't be tempted to turn up the heat.

How Much Humidification Is Too Much?

Besides making sure that the moisture from your humidifier is pure and clean, it's also important to maintain a proper level of humidity in your home. While dry air is definitely uncomfortable and can lead to discomfort, too much moisture in the air leads to another set of problems: mold and dust mites thrive in overly moist environments, so improperly maintained levels of humidity could cause further irritation to allergy and asthma sufferers.

To keep your home environment comfortably humid without encouraging dust mite and mold growth, experts recommend indoor humidity levels between 40% and 50% for allergy sufferers. Some humidifiers, like the Air-O-Swiss AOS7135 Ultrasonic Antimicrobial Humidifier, come with a built-in hygrometer (humidity gauge). If you have another type of unit, a humidity gauge like the Acu-Rite Digital Humidity Gauge helps keep humidity levels within range. This humidity gauge also features a clock, light, and digital thermometer, and is useful in determining which areas of the home need humidification during dry seasons and dehumidification during wet seasons. The Germ Guardian Ultrasonic Digital Humidifier has a digitally adjustable spray function and timer, allowing you to adjust the percentage of vapor.

Humidity levels in the home are an important component of relieving allergy and asthma systems through environmental control. Especially during the winter, when dry air tends to be more of a problem, asthma and allergy sufferers can greatly benefit from environmental control of indoor humidity levels. Humidifiers make this possible.

Originally published in the January 2008 issue of Allergy Consumer Report.

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