Do you suffer from dry/itchy eyes, throat or skin?  Do your asthma symptoms get worse during the winter?   If you've answered yes to any of these questions, your air may be too dry.  In addition to health benefits, a quality humidifier can also reduce static electricity, peeling wallpaper, and cracks in paint and furniture.  Learn more about humidifiers and see a comparison chart of some of most popular models below. 

Do You Need a Humidifier?

There are two basic types of moisture problems that can exist in your home: excess or insufficient moisture.  Excess moisture causes damage to furnishings and promotes mold growth.  Dehumidifiers can solve this problem by drawing out moisture from your air.  Insufficient moisture in the air can cause dry nasal passages, increased respiratory problems and excessive static electricity in clothing and carpets. Humidifiers will add moisture to the air when it's too dry.  The chart below illustrates how humidity levels can affect your home and overall health:

About Humidity Levels

Humidity is expressed in ways such as absolute humidity and relative humidity. Absolute humidity refers to the mass of water vapor divided by the mass of dry air in a volume of air at a given temperature. So the hotter the air, the more water it contains.

According to the American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE) Standard Environmental Conditions for Human Occupancy, it's recommended that relative humidity be kept between 30% to 50% in the summer and 30% to 40% in the winter. To get an idea of the human perception of humidity, look to the chart below:

What is a Humidifier?

Humidifiers are household appliances that increase humidity. They emit water vapor or mist to increase moisture levels. Humidifiers come in a range of sizes. Room humidifiers are commonly used in individual rooms while whole house humidifiers cover large areas - sometimes up to 2,500 square feet. Humidifiers will usually fall into one of these two categories: cool mist or warm mist. 

Cool Mist Humidifiers

Cool mist humidifiers are some of the most popular variety of humidifiers. Because they don't actually heat the water in the tank, there's no risk of burn, making them great in a child's bedroom. Cool mist humidifiers are usually more energy efficient because there's no heating element, but they're generally noisier and require frequent filter changes due to bacteria growth. There are three different types of cool mist humidifiers: evaporative/wick units, impeller models, and ultrasonic humidifiers.

Evaporative Humidifiers

Evaporative humidifiers usually have a wick or filter that's used to absorb water. This water is evaporated by a fan and pushed out of the unit. Evaporative humidifiers offer a more natural form of humidification. As your moisture levels increase, the evaporation rate will gradually decrease. While these work great, many people dislike the noise created by the unit's fan.

Impeller Humidifiers

These humidifier units have a spinning disk that's submerged in the water tank. This disk is what actually creates the mist. Humidifiers with impellers tend to be quieter to evaporative, fan-based models.

Ultrasonic Humidifiers

These are some of the most modern humidifiers you'll find on the market. An ultrasonic humidifier has a small metal diaphragm that vibrates at an ultrasonic frequency. This vibration creates water droplets without creating noise, and the mist can be described as a cool fog. Many ultrasonic humidifiers will also have antibacterial features to prevent stagnant water.

Humidifier Tip:

Consider your climate when shopping for a humidifier.  Cool mist humidifiers are recommended for warm, dry aress while warm mist humidifiers are better for cool, dry areas.

Warm mist humidifiers aren't as popular cool mist humidifiers, but the warm mist produced by these units can be extremely soothing during the cold or flu season.  All warm mist humidifiers have some sort of heating element that heats the water in the tank.  As a result, they use more electricity than cool mist humidifiers and can be a burn risk.  However, because these humidifiers heat water before dispersing it into the air, so there's significantly less room for bacteria growth, meaning less filter changes are required.  Almost all warm mist humidifiers use steam to add moisture to your air. 

Steam

These are the simplest and least expensive.  Water is boiled and sent out as steam, which then kills any mold or bacteria.  Many offer the benefit of dispensing medications for inhalation, but they're not suitable for use with children because of the burn risk. 

Cool Mist Versus Warm Mist Humidifiers - Which Should You Choose? 

Both types are equally effective at adding humidity to the air, but each has pros and cons.  The one you choose will really depends on personal preference.  Look at the charts below for a quick overview of the two: