Why Is a Home Dehumidifier Important?

A dehumidifier matters when your home holds more moisture than it should, because it pulls that water out of the air before it can feed mustiness, mold and damage to wood and finishes. In a dry region like ours it is not something every house needs, but for basements, crawl spaces and tightly sealed homes it can make a real difference.

It is worth understanding what the machine does and what it does not do, so you buy the right thing and put it in the right place.

What a dehumidifier actually does

A dehumidifier draws air across a cold coil, so water vapor condenses into droplets that collect in a bucket or drain away through a hose. The drier air is then returned to the room. Portable models treat a room or a floor, while whole-house equipment connects to the ductwork and treats the entire home. The right size depends on the space, how damp it starts and how tightly the house is sealed.

Your air conditioner also removes some moisture as it cools, which is one reason a system sized correctly matters. An oversized air conditioner cools fast and shuts off before it has done much drying, leaving the air cool but clammy.

Where it helps most

• Basements and crawl spaces where ground moisture works its way up.
• Bathrooms and laundry areas that stay damp after use.
• Newer, tightly built houses that hold indoor moisture in.
• Rooms where stored items, books or wood furniture are at risk.
• Homes that stay shut up during the long humid stretches after a wet spell.

Keeping humidity in a moderate band also helps the rest of the house last. Wood floors, cabinets and trim move less, paint holds up better and stored belongings are less likely to pick up that musty smell.

Signs you may need one

Look for windows that fog or drip inside, a musty smell that returns after cleaning, dark spotting on walls or ceilings, damp or clammy feel in the air, and water stains that show up without any leak you can find. A cheap hygrometer will show a number instead of a hunch, and readings that stay well above the 50 percent mark are a common signal to act.

A dehumidifier treats the symptom, so it pays to look for the cause as well. Check that bathroom and kitchen fans vent outdoors, that the dryer vent is intact, that the ground slopes away from the foundation and that the crawl space is not open to damp soil. Sometimes the fix is simpler and cheaper than more equipment.

Keep it running properly

Empty the bucket or clear the drain line as directed, clean the filter and keep the machine away from walls so air moves freely. A unit that is never emptied or whose coil ices over is not doing its job. Whole-house equipment should be part of regular maintenance visits along with the rest of the system.

Portable or whole-house

A portable unit is the easy first step for one damp room. It plugs into a wall, needs emptying unless it drains by hose, and it is not built to treat a whole floor plan. Whole-house equipment costs more effort to install but works quietly in the background, drains itself and evens out humidity from room to room.

Whichever you pick, place it away from walls and furniture, keep doors to the treated space closed so it is not fighting the rest of the house, and set the humidity target moderately. Pulling the air too dry brings its own problems, from static shocks to shrinking wood.

If you suspect humidity is a problem in your house, the Air-Tech office in Pasco is at (509) 392-2021, open Monday to Friday, 8 to 5.