Dehumidifiers Vs. Humidifiers

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A home's comfort level relates to several factors, including the humidity., which is the amount of moisture in the air. Humidifiers and dehumidifiers are machines that help control the humidity of either an individual room or an entire home, depending on the type and size. An understanding of humidity levels and the functioning of each type of machine helps you make the best selection.

Humidity Levels

Humidity levels that are either too high or too low affect your health and your home. During the warmer months, high humidity can encourage mold growth. Low humidity dries out the skin and sinuses, which can make you more susceptible to respiratory illnesses, according to North Dakota State University. The dry air also negatively affects wood in the home, causing it to shrink.

An electronic humidity gauge allows you to determine a general humidity level in the home. A range between 30 and 40 percent is ideal during winter. Summer humidity levels are best below 65 percent. Without a humidity gauge, look for condensation on the windows as a sign of high humidity. Dry skin or dry sinuses alert you to a potential lack of humidity.


Dehumidifiers draw water from the air to lower the overall humidity. They draw air into the unit, where the excess water is removed. The drier air circulates back into the room. Dehumidifiers work more efficiently in warmer temperatures with high humidity.

Humidifiers serve the opposite function in a home. They add moisture to the air of the home through a mist or vapor, depending on the type.


Depending on your home's humidity situation, either a humidifier or dehumidifier allows you to raise or lower the moisture level in the air. A humidifier corrects overly dry air, helping your skin and sinuses to feel better while avoiding damage to wood furniture. A dehumidifier prevents mold growth, reduces window condensation and prevents water-related stains and other damage associated with excessive humidity levels.


Dehumidifiers come in three main types: heat pump, chemical absorbent and dehumidifying ventilators. They all remove moisture from the air, but each has a slightly different method. The heat pump method draws in air with a fan and runs it across a cold coil to condense the moisture. Air is warmed by a heat pump and returned to the room. Chemical absorbent dehumidifiers send damp air outside after a chemical drying agent absorbs moisture from room air. Dehumidifying ventilators use a sensor and exhaust fan to determine when humidity levels are high.

Humidifiers also come in different varieties. Central humidifiers connect to the heating and cooling system. Ultrasonic units employ ultrasonic vibrations to create the mist. A rotating disk distributes the mist in an impeller model. Evaporating humidifiers use a wick, belt or filter to absorb water, which is dispersed by a fan. Vaporizers heat the water to create steam.


Your home's humidity level determines whether you need a humidifier or a dehumidifier. You might need both machines at different times of the year. For example, the drier air of winter might cause you to need a humidifier, but when summer arrives the humidity levels might necessitate the use of a dehumidifier.