Energy Efficient Dehumidifiers

Choosing an Energy Efficient Dehumidifier

When shopping for a dehumidifier there are a number of important factors to consider:

• Capacity: The capacity of a dehumidifier, measured in pints per 24 hours (typically between 10 and 44) is determined by considering the size (ranging between 500 and 2,500 square feet) and condition (moderately damp, very damp, wet, or extremely wet) of the space to be dehumidified. It is important to pick a dehumidifier properly sized for the conditioned space.
• Energy Factor: Measured in liters of water removed per kWh of energy consumed, a higher energy factor signifies a more efficient dehumidifier.
• Water Removal Options: A removable plastic bucket (with warning lights and automatic shutoff to indicate and avoid overflowing when the bucket is full) is typically used, which coupled to a hose, directs the water into a floor drain or sump.
• Placement: If configured with a top-mounted air discharge, the dehumidifier can be placed against a wall. Otherwise, care should be taken to ensure that the dehumidifier is located away from walls and large furniture to allow for free circulation of air. The dehumidifier should  be placed away from areas where there is a lot of dust and dirt to avoid clogging the coils and grills  and from electrical circuits/devices/cords/connections where water drainage would be a concern.  The dehumidifier should also be connected to a properly grounded outlet and in close proximity to a floor drain or sump to avoid long hose runs.
• Operating Temperature: In spaces where the ambient temperature typically falls below 65 degrees, residential customers should buy a product with specifications calling for lower temperatures. Units are available that are rated for use at temperatures as low as 42 degrees. Otherwise, frost will form on condensing coils causing the compressor to cycle without removing moisture from the air. In this case, the recommended action is to switch off the equipment and allow the unit to defrost.
• Relative Humidity: Relative humidity (RH) is the amount of water vapor in the air compared to the amount that could be held at the particular temperature. The optimum level for a building will range between 30 and 50 percent; anything above that level will typically stimulate bacteria growth. Most dehumidifiers are equipped with built-in devices that cycle the dehumidifier on and off relative to a present RH level.

Energy Efficient Dehumidifiers have Lower Life Cycle Costs

Qualified dehumidifiers have more efficient refrigeration coils, compressors, and fans than standard models and they use less energy to remove the same amount of moisture. These better dehumidifiers are usually 10 to 20 percent more energy efficient and will result in an annual average savings in the range of $20 or over $230 in savings over the typical lifespan of a unit.