Dehumidifier

If you live close to the equator or near a coastal region, you probably hear your local weatherman say the word "humidity" all too often. But no matter where you are, you've surely experienced it -- that muggy, heavy feeling that fills the air, often when it's rainy, foggy or hot outside. It can make your hair frizzy and may seem to dampen everything, including your mood.

When people complain about humidity, for the most part they're talking about relative humidity. Depending on temperature, air can hold a fixed amount of water vapor; relative humidity is the ratio of actual vapor in the air to this fixed amount. For example, at a temperature of 68 degrees Fahrenheit (20 degrees Celsius), one cubic meter (35 cubic feet) of air can hold about 18 grams (.6 ounces) of water. This would be a state of saturation, otherwise known as 100 percent relative humidity.