Control moisture in your home

Reducing excessive moisture in your home can help combat unpleasant musty smells and allergies caused by the growth of bacteria and mold. Many people choose to use dehumidifiers to help control moisture and improve the air quality in their homes.

For fresh air and energy savings, purchase an energy-efficient dehumidifier. The average ENERGY STAR® certified dehumidifier can save up to $175 over the life of the unit. Look for the blue ENERGY STAR label when you shop—and take advantage of the $25 rebate on ENERGY STAR certified dehumidifiers.

Moisture can enter your home from many places and many homes have more than one source of moisture. Reducing the amount of moisture entering your home is the best way to solve moisture problems. Read tips on how to reduce moisture in your home.

A dehumidifier can help maintain the humidity in your home at optimal levels to improve the quality of air, but it should be properly sized for the needs of your home. A dehumidifier that is too large will waste energy and lead to higher electricity bills. Read our step-by-step guide to help you choose the right dehumidifier size for your home.

How to choose the right size dehumidifier

Bigger isn’t always better. The size you'll need depends on the size of the area to be conditioned and the amount of moisture present in the air.

  Size in pints per 24 hours
Dampness 500 sq. ft. area 1000 sq. ft. area 1500 sq. ft. area 2000 sq. ft. area
Moderately Damp - space feels damp and smells musty only in warm, humid weather. 10 pints 14 pints 18 pints 22 pints
Very Damp - space always feels damp and smells musty. 12 pints 17 pints 22 pints 27 pints
Wet - feels and smells wet. Seepage occurs. Mold and mildew growing on surface. 14 pints 20 pints 26 pints 32 pints

Source: Association of Home Appliance Manufacturers

Tips to reduce moisture in your home

Common indications of excess moisture:

  • Wet stains on walls and ceilings
  • Stuffy feeling in room
  • Rotting wood
  • Condensation on windows
  • Musty smells
  • Allergies (if the air in your home is too moist, it will encourage the growth of bacteria and mold, common allergens)
Moisture can enter your home from many places and many homes have more than one source of moisture. Cooking, bathing and even our own breath put moisture to the air. Also, sources outside your home can increase the moisture inside. Too much indoor humidity can promote the growth of mold, mildew, and bacteria.

Try these simple actions to avoid excessive moisture:

  • Keep basement and crawl spaces sealed off from the outdoors.
  • Install gutters and divert roof runoff away from the foundation.
  • Improve grades around the foundation to drain water away.
  • Cover dirt floors in crawl spaces and basements with heavy duty plastic.
  • Ensure that clothes dryers are properly vented to the outdoors.
  • Wrap cold water pipes with pipe insulation to eliminate sweating.
  • Use exhaust ventilation to remove moisture generated by showering, bathing and cooking.
  • Reduce the number of plants in humid areas.
  • Do not store wet firewood in the basement.
  • Do not open basement windows and doors in the summer to dry out the basement. This can make the problem worse by allowing moist outdoor air into your cool basement, causing increased condensation.

Other factors to consider in properly sizing a dehumidifier

  • ENERGY STAR® qualified models remove the same amount of moisture as similarly sized standard units, but use at least 10% less energy and in some cases up to 23% less.
  • Check the EnergyGuide (a yellow form attached to the appliance) to check the overall yearly energy consumption for that model. Even ENERGY STAR models can vary in energy use.
  • Check the energy factor information of any dehumidifier you intend to purchase. The energy efficiency of dehumidifiers is measured by its energy factor, in liters of water removed per kilowatt-hour (kWh) of energy consumed or L/kWh. In general, a higher energy factor means a more efficient dehumidifier. Energy factors can be found on the ENERGY STAR product list.

Tips for operating your dehumidifier

  • Basements are typically damp, and a dehumidifier can effectively reduce humidity levels once the moisture source is under control. You can use a hygrometer, an inexpensive humidity gauge, to measure your humidity level. Hygrometers can be purchased at most local hardware and electronics stores.
  • During summer months, humidity generally runs between 60 and 80 percent. An indoor relative humidity of up to 70 percent is generally comfortable for most people and acceptable for basements or long-term storage.
  • During winter months indoor relative humidity will naturally be lower than in summer months - relative humidity of 30 percent to 40 percent in winter will reduce moisture problems. It is unlikely that a dehumidifier is needed in Vermont during the winter. If a dehumidifier is needed, see the tips to reduce moisture in your home.
  • Keep an eye on the relative humidity. Contain the area to be dehumidified by closing windows and doors. Once the desired level of humidity is achieved, continuing to remove moisture will increase energy consumption and over-dry the space. Do not use a dehumidifier when the temperature is less than 60 degrees Fahrenheit in the area in which you are conditioning.

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