Dehumidification

Whole-Home Dehumidification Systems

Whole-home dehumidification systems tie into your existing ductwork and remove humidity without running a full air conditioner. Since they do not need to cool the air, they use significantly less energy than an air conditioner. However, portable dehumidifiers take care of most residential home needs, while whole-home dehumidification systems could be a solution for controlling persistent humidity issues.

Dehumidifiers

ENERGY STAR® certified model possess more efficient refrigeration coils, compressors, and fans than conventional models. They also use less energy to remove moisture, with 13 percent more efficiency. An ENERGY STAR® certified model removes the same amount of moisture as a similarly sized standard unit. In fact, the energy saved by an ENERGY STAR® certified dehumidifier could power your refrigerator for two months.

Other Ways to Reduce Humidity

• Improve the drainage around the foundation of your home or business.
• Properly vent clothes dryers to the outdoors.
• Use vent fans in bathrooms and kitchens to remove humidity at the source.
• If your home or business uses a cold-climate heat pump or central air conditioning, consider installing a vent in the humid space and take advantage of the dehumidifying capabilities of these systems. In colder months, high-efficiency heat pumps remove moisture from inside the home as warm air is circulated. Many heat pump models include a “dry mode” that’s specifically designed to dehumidify a room.
• Upgrade to a heat pump water heater , which provides dehumidification in addition to greater efficiency and better indoor air quality. Heat pump water heaters draw both air and moisture from their surroundings, and if installed in a humid location (e.g., basement), reduce the need to run a dehumidifier.

Buyer's Guide to Dehumidifiers

• Ask for an ENERGY STAR® model: When purchasing a dehumidifier from a retailer, requesting an ENERGY STAR® certified model ensures you reap the greatest savings.
• Check the yellow EnergyGuide Label: Use the yellow EnergyGuide Label to determine the model's energy use, compare the energy use of similar models, and estimate annual operating costs.
• Water Removal Options and Drainage: Most portable dehumidifiers use a removable plastic bucket and warning lights to indicate when you need to empty the bucket. There's typically an automatic shut off mechanism to prevent any bucket overflow. Most dehumidifiers come with a fitting that allows you to hook a hose directly to the bucket, which can be directed into a floor drain or sump pump.
• Placement: For optimal performance, locate dehumidifiers with top-mounted air discharge against walls and dehumidifiers without top-mount discharge away from walls and furniture so air circulates freely around the unit.  
• Operating Temperature: If the temperature for the dehumidified space falls below 65ºF, consider purchasing a dehumidifier specifically designed for use at lower temperatures.
• Relative Humidity (RH) and Humidistats: Humidity, the amount of moisture or water vapor in the air, typically refers to Relative Humidity (RH). The optimum RH level for a building resides between 30% and 50%. Anything above this range promotes bacteria growth. (In colder climates, during the heating season, humidity levels should be in the range of 30% to 40% RH to prevent window condensation.)
• Energy Factor: A dehumidifier's energy factor measures its energy efficiency 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.
• Capacity: When determining a dehumidifier's capacity, usually measured in pints per 24 hours, consider the size of the dehumidified space and the conditions that exist within the space before dehumidification.

Energy Saving Tips for Dehumidifiers

• Shop for an ENERGY STAR® certified dehumidifier with a humidistat. Humidistats allow you to set the desired relative humidity level for a room or area in your home or business.
• When operating a dehumidifier, closing all doors and windows to the space your dehumidifying ensures the dehumidifier runs as efficiently as possible.
• Locate away from sources of dust and dirt (like woodworking equipment), which can clog coils and grills.