May 2023 EnergyWise SM Tip: Dehumidifiers

By: Energy Efficiency Program Manager Cory Fuehrer

If you live in Nebraska, you know it can get hot in the summer. But if you live in the eastern half of the state, you probably know with heat usually comes humidity, which can make things sticky!
The amount of moisture or water vapor in the air is most often talked about in terms of Relative Humidity (RH). RH is the amount of water vapor actually present in the air compared to the greatest amount of water vapor the air can hold at that temperature. Depending who you talk to, recommended RH levels for a home are generally between 30 and 55 percent. Anything above this range may promote bacteria growth. During winter, humidity levels should be in the range of 30 to 40 percent RH to prevent window condensation. Summertime comfort is usually achieved between 45 and 55 percent RH.

To reduce indoor humidity levels in the summer, many people use a dehumidifier. These units work by drawing moist air over a refrigerated coil with a fan. The evaporator coil is kept cold by a compressor. As moist air passes through this coil, it cools and condenses water vapor. The air is then reheated by the condenser coil and blown into the room. A dehumidifier’s operating capacity is usually measured in pints of water removed every 24 hours. Two main factors impact its operation: the size of the space that needs to be dehumidified and conditions that exist in the space before dehumidification. What many people do not realize is running a dehumidifier can use the same amount of energy as a small air-conditioner. Unfortunately, when they receive their first summertime electric bill, the extra kilowatt-hours and dollars charged become a cold reality check!

What can you do to manage a dehumidifier’s impact on your budget? If you choose to use a dehumidifier, do so in the most efficient way possible. Most dehumidifiers have top-mounted air discharge and can be placed against walls. If you do not have top-mounted air discharge, make sure the dehumidifier is located away from walls and furniture so air can circulate freely around the unit. Operate your unit away from sources of dust and dirt, which can clog coils and grills. Finally, be sure all exterior doors and windows to the space being dehumidified are closed while the unit is running so you are not continually bringing in outside air with a higher humidity level.

Note that dehumidifiers receiving ENERGYSTAR® recognition have more efficient refrigeration coils, compressors and fans than conventional models. They remove the same amount of moisture, but use nearly 30 percent less energy compared to less efficient models.

There are other ways to control home humidity levels, too. If you’re already cooling your home with a central air-conditioning system, your indoor unit is also dehumidifying while bringing the air temperature down. Consider having an additional air register installed in the humid space in your home, and take advantage of the air conditioner’s dehumidifying capabilities. This will also help improve airflow between humid and drier parts of your home.

How about keeping moisture out of your home in the first place? Extend downspouts from your gutters, and direct them away from your home’s foundation. Ensure soil slopes away from your
foundation to avoid water pooling around your home. Avoid over-watering grass and other plants right next to your house. Repair leaking outdoor faucets attached to the side of your home.
Ensure clothes dryers are properly vented to the outdoors and not dumping their moist air inside. Use vent fans in bathrooms and kitchens to remove humidity at the source. Do not forget to turn
fans off when you are done creating additional humidity, or you will continue venting your nicely air-conditioned air!

Your local utility and Nebraska Public Power District want to help you keep cool this summer!
This includes helping you manage indoor humidity levels. For more ideas on how you can make
your home or business EnergyWiseSM, as well as financial incentives to help with the cost of
your energy-saving upgrades, contact your local utility or visit www.energywisenebraska.com.