Dehumidifiers remove moisture from the air. How long your dehumidifier lasts depends on several factors, including your climate and local weather conditions. Dehumidifiers work less effectively in colder temperatures. Owners of well-sealed, energy efficient homes have a greater need for their dehumidifiers as water vapor-filled air remains trapped indoors, while draftier homes experience greater ventilation, which can lower the humidity naturally.

Life Expectancy

The National Association of Home Builders estimates eight years as the average lifespan of a dehumidifier and three to five years as the typical lifespan of consistently-used residential units under normal operating conditions. The Association's study based the estimate on surveys of manufacturers, trade associations and researchers.

Influencing Factors

The amount of use your unit sees is one of the major determining factors affecting how long your dehumidifier will last. Units in constant use and those improperly matched to the size of the area you're trying to treat will experience greater wear, potentially shortening their lives. In addition to defects and mechanical failures, reasons you may choose to replace your unit include the desire for a quieter, more efficient model, or to upgrade to dehumidifier with more or better features.

Sizing

Select a dehumidifier sized to fit the space you want to treat. Dehumidifiers come in a range of capacities. Small units remove 25 to 30 pints of water from the air per 24-hour period, medium-sized units remove up to 45 pints and perform well in areas such as kitchens, and large units remove 50 to 75 pints, making them good for areas with wet conditions, such as garages. Whole house units are also available.

Life Extension

To extend the life of your machine, the Repair Clinic website recommends you wait at least 10 minutes before turning your dehumidifier on again after turning it off to allow the pressure in the refrigeration system to equalize. Locate the dehumidifier in a spot that allows good airflow around the unit. Understand and maintain the proper relative humidity indoors for the temperature and conditions. Attempting to remove all of the moisture from the air can damage wood, make people and pets uncomfortable and leads to undue wear on your dehumidifier. Units that run constantly may have a defect, need maintenance or may be on the wrong setting.

Reducing Moisture

Take some of the burden off of the machine by reducing indoor moisture in other ways. Use ventilation fans in areas where greater water use causes moisture to build in the air, such as bathrooms, kitchens and laundry rooms. Open windows during good weather. Consider installing a central heating or air conditioning unit, which will treat the air in the entire living area. Attend to any plumbing and drainage issues that may lead to moisture in and around your home.