A dehumidifier is used to remove moisture from the air inside your home. Too much humidity can weaken your home's structure, attract pests and even make you sick.

An obvious sign of too much moisture is condensation on the windows. Cracks in wood furniture may be a sign of dry air.

The fixed amount of water vapor that air can hold varies according to the air temperature; relative humidity is the ratio of actual vapor in the air to this fixed amount.

The relative humidity is 100 percent at the state of saturation.

For a home with a temperature of 68 degrees Fahrenheit (20 degrees Celsius), the ideal relative humidity should be between 30 and 50 percent.

Just like a soda can, a dehumidifier cools warm air, which causes condensation. Condensation is moisture that has been removed from the air.

The reservoir collects moisture that the dehumidifier removes from the air. Make sure to empty the reservoir regularly, or you may have a sopping wet mess.

A dehumidifier can help decrease the amount of time you use your air conditioner because air feels cooler as excess moisture is removed, and the water collected in the dehumidifier can be recycled.

Moist air promotes the growth of allergens such as fungus and mold. For those without allergies, preventing mold in your home is still good advice to follow.

Dehumidifiers start at about $150. Although not cheap, a dehumidifier can more than pay for itself in the health benefits it brings to you and your family.

A humidistat measures relative humidity. Some dehumidifiers have programmable humidistats that allow you to set the desired level of relative humidity.

The condensation collected by a dehumidifier is referred to as gray water. Gray water isn't suitable for drinking or cooking but is great for watering plants.

Some types of dehumidifiers use desiccants to absorb moisture; to get an idea of desiccants, think of the little paper packets that come in the box of a new pair of shoes. Desiccant dehumidifiers do not cool the air, so they are used mostly in very cold climates.

Creepy crawlers like a moist environment. Dehumidifiers remove excess moisture to make your home unattractively dry for them.

Creaky stairs may be a sign of excess moisture in your home, since wood swells as it absorbs moisture.

Promptly repairing leaks will prevent excess moisture from accumulating in your home. Even if you choose not to buy a dehumidifier, you should still take steps to remove excess moisture.

The most common dehumidifier is known as the refrigerative dehumidifier, since a refrigerator and this type of humidifier both have a compressor and cooling coils.

A dehumidifier's fan pulls in air and blows it across cooling coils or a desiccant to draw out moisture.

The final stage of the dehumidifying process is to warm the air and exhaust it. An air conditioner operates similarly, but it does not heat the air.

A portable dehumidifier should be placed away from walls and furniture so the air can circulate.