New dehumidifier standards will help dry up excess energy use

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Joanna Mauer

On Friday, the US Department of Energy (DOE) finalized new efficiency standards for dehumidifiers. In addition to reducing the power consumption of a major energy hog, the new standards will also ensure that dehumidifiers perform efficiently in the basements where they are most commonly used.

About 13% of US homes and 25% of homes in the Northeast and Midwest (where basements are common) use a dehumidifier. Dehumidifiers just meeting the current standards can consume as much as 1,000 kilowatt-hours (kWh) per year, or more than twice as much as an average new refrigerator. The new standards will improve dehumidifier efficiency by 60-70% relative to the least-efficient products on the market.

DOE estimates that with the new standards consumers will save $100-140 on average over the lifetime of a dehumidifier. On a national level, the standards will save 30 billion kWh over 30 years of sales, an amount equal to the annual electricity consumption of about 3 million US households, and save consumers $1.3-2.7 billion.

The new standards cover both portable dehumidifiers and whole-home dehumidifiers. Portable dehumidifiers make up more than 95% of sales and can be easily moved from one room to another. Some portable dehumidifiers collect water in a bucket, while others can be connected to a drain. Whole-home dehumidifiers are often used in conjunction with a home’s HVAC system and are designed to be connected to ductwork that supplies conditioned air to a whole house.

Dehumidifiers work by using a refrigeration system to cool air to the point where moisture in the air condenses. The new standards can be met by using more-efficient compressors and larger heat exchangers.

The new standards are based on an improved test procedure that will better reflect the actual energy consumption of dehumidifiers in homes. Currently, dehumidifiers are tested at an ambient temperature of 80o F. However, most dehumidifiers are used in basements, where temperatures are typically significantly lower than 80o F. With the new standards, dehumidifiers will be tested at 65o F, which will encourage the development of products that perform efficiently at typical basement temperatures.

The new standards will also help reduce energy waste that’s not captured by the current standards. On some dehumidifiers, the fan runs continuously, even when the compressor is off, wasting a significant amount of energy. The new test procedure captures power consumption when the compressor is not running including standby power and any fan power.

DOE’s analysis showed that higher efficiency levels than those adopted in the final rule would achieve greater savings for consumers, but the agency chose not to select those higher levels because of concerns about impacts on manufacturers. A new ENERGY STAR specification for dehumidifiers, which will take effect in October and is stronger than the levels adopted in the DOE final rule, will help drive the market towards even higher-efficiency products. The new ENERGY STAR specification will also help lay the groundwork for a future stronger minimum standard.

The new standards for dehumidifiers will take effect in 2019.