Room air humidifiers help to improve air quality and alleviate symptoms of dry air, such as sinus headaches, dry skin, sneezing and coughing. During the dry winter months, when forced air heating systems can severely dry out the air, humidifiers are an excellent way for you to add back essential moisture into the air. Dry air is often the source of many ailments, such as dry skin, itchy eyes, and cracked lips. It affects everyone equally, regardless of allergies or asthma. It can even damage wood furniture, causing it to crack. Low humidity levels in your air can also dry out the mucous lining inside your nose and throat, causing sore scratchy throats, nose bleeds, and sinus infections. Adding a room air humidifier to your nursery can help your baby sleep comfortably at night, and is also a great way to help prevent colds and the spread of germs during the flu season.

Humidity Levels:

The optimal humidity level for overall healthy air ranges from between 30% to 50% relative humidity. An inexpensive humidity/temperature gauge (hygrometer) allows you to easily monitor the relative humidity level in your room. While low humidity levels below 30% are unhealthy, you also want to make sure not to have too much moisture in the air. Room air humidity levels higher than 50% can actually encourage the growth of mold, bacteria, fungi and dust mites. You can often tell if you have too much humidity by looking at your windows. Condensation buildup on windows is a telltale sign of too much humidification. Most humidifiers have built-in humidistats which you can adjust to your liking, thereby varying the amount of humidity you add to the room. More expensive models also have hygrometers built-in, with readouts or gauges telling you the humidity level in the room, and allowing you to specify the exact level of humidity you prefer.

Types of Humidifiers:

There are many different types of humidifiers from which to choose. They vary in both size (or gallon output per day), and method of humidification (cool mist, evaporative, warm mist, and ultrasonic). The largest sizes of humidifiers are called console humidifiers, which are capable of humidifying multiple rooms and very large areas. Room humidifiers are smaller units better suited to single small, medium or large sized room in your home and office. Here is a brief overview of the different types of humidifiers:

Cool Mist Evaporative Humidifiers
The most common type of humidifier, a cool mist evaporative humidifier adds moisture into the air using the principles of natural evaporation, which is the cleanest method of humidification. A wick filter (sometimes also called a wicking filter) sits in the base of the humidifier and absorbs water. A fan then blows dry room air through the saturated wick filter, causing the water in the filter to evaporate into the room, thereby adding moisture into the air. The wick filter also traps any impurities, such as minerals, that may be present in the water, ensuring that the moisturized air is completely pure, clean, and free of any minerals or impurities.

• Pros: Wick filter ensures a pure and clean mineral-free moisture output. Very low power consumption. Fans can be powerful enough to cover large areas with a single humidifier.
• Cons: Fans make more noise than other types of humidifiers (noise level depends on fan speed). Wick filter needs to be replaced approximately every 2 months. Bacteria and mold can grow on wick filter.

Warm Mist Humidifiers
Warm mist humidifiers use a heating element to boil the water in the humidifier and release it into the air in the form of a warm steam. If you live in a cold climate, using a warm mist humidifier will help make the room feel warmer than it actually is (as opposed to a cool mist humidifier, which can have the opposite effect). Warm mist steam humidifiers are quieter than cool mist evaporative humidifiers, because they do not use a fan. Instead, the heating element simply boils the water into a pure steam, which rises into the air free of all minerals and impurities. Any mineral content that was present in the water is left behind in the humidifier, and will not enter the room air. Mineral deposits left behind in the humidifier can be removed using vinegar. Some models also use optional mineral absorption pads, which help to absorb the mineral deposits before they can stick to the humidifier.

• Pros: Quiet operation, no wick filters to replace, pure clean mineral-free moisture output.
• Cons: Higher power consumption (heating element uses more electricity than other humidifiers), most units are limited to small rooms only, may pose a burn risk for small children if the humidifier is accidentally tipped over.

Ultrasonic Humidifiers (cool or warm mist)
Ultrasonic humidifiers are the quietest humidifiers around. They are so quiet, they are often described as being nearly silent. An ultrasonic humidifier uses the power of high frequency sound waves to vibrate a metal diaphragm at an "ultrasonic" frequency, thereby breaking the water in the humidifier down into an ultra-fine vapor mist. This vapor mist, which looks like a fog, is released into the air using a very small and quiet fan. Any minerals or impurities that are present in the water are released into the air with the mist. Many ultrasonic humidifiers use demineralization cartridges, which serve to trap these minerals before they are released into the air, although the demineralization cartridges are usually not 100% effective. You may want to use distilled water if you experience a problem with "white dust" settling on surfaces near the humidifier. Some ultrasonic humidifiers have a heating option as well, which heats up the water before releasing it into the air. This helps eliminate bacteria growth in the water, and also keeps the room from feeling too cold.

• Pros: Ultra quiet, near silent operation, no wick filters to replace, low power consumption.
• Cons: Unless using distilled water, impurities will enter the air in the form of "white dust" (this can sometimes be controlled with a demineralization cartridge), most ultrasonic humidifiers are limited to small rooms only.

Warm Mist Vaporizers
A vaporizer is basically a simpler, less expensive and less powerful version of a warm mist humidifier. They are typically made in smaller sizes and can be used as an inexpensive, basic humidifier for a small room. Most vaporizers just have an on/off switch, and do not have any moisture output controls. There are no filters to replace with a warm mist vaporizer.

• Pros: Quiet operation, no filters to replace, pure clean mineral-free moisture output.
• Cons: Higher power consumption (heating element uses more electricity than other humidifiers), limited to small rooms only, no humidity adjustment controls.

Cool Mist Impeller Humidifiers
In a cool mist impeller humidifier, a high speed rotating disc spins water towards a diffuser, which then breaks the water down into tiny droplets, which are then released into the air as a visible fine mist. Impeller humidifiers are typically very quiet, and do not require any replacement filters. However, minerals or other impurities that are present in the water will be released into the room in the form of a fine water mist. These minerals tend to settle on surfaces such as furniture, and can result in what is called "white dust", which may look like a ultra-fine layer of dust on surfaces surrounding the humidifier. Therefore, it is advisable to use only distilled water with an impeller humidifier, as distilled water has no mineral content.

• Pros: Quiet operation, no filters to replace, low power consumption.
• Cons: Unless using distilled water, impurities will enter the air in the form of "white dust".

How do I choose?

The two most important factors to consider when choosing a room air humidifier are the size of your room, and the type of humidifier you prefer. You can learn more about the differences between warm mist and cool mist humidifiers by clicking on the "Warm Moisture or Cool Moisture?" link below, or you can start shopping by room size or by price by clicking on one of the below links: