How Much Energy Does a Dehumidifier Use? | Rated in Watts & kWh

If you’re shopping for a dehumidifier, the first question is usually “how much energy does a dehumidifier use?” The answer depends on two things you control—capacity and efficiency—and one you don’t: how damp your space is. A unit running eight hours a day in a musty basement draws far more power than the same model cycling on twice daily in a dry bedroom.

What Determines a Dehumidifier’s Energy Use?

Three factors decide electricity draw: capacity (pints per day), efficiency rating, and runtime. Capacity tells you how much moisture the unit removes, not how much power it draws—a common mix-up that overestimates energy use.

Efficiency is where differences show. The U.S. Department of Energy measures dehumidifier efficiency in liters of water removed per kilowatt-hour (L/kWh) under test conditions. A higher number means more moisture wrung out per dollar. The ENERGY STAR program certifies portable models with an Integrated Energy Factor of at least:

• 1.70 L/kWh for units up to 25 pints/day
• 2.01 L/kWh for 25.01 to 50 pints/day
• 3.30 L/kWh for units over 50 pints/day

Whole-home dehumidifiers use a different metric based on case volume, so don’t compare portable numbers to ducted systems—they’re not on the same scale.

Estimating Your Actual Electricity Cost

Estimate energy cost with a simple federal formula: annual kWh = operating watts ÷ 1,000 × hours run per year. Multiply by your electricity rate for a realistic yearly cost.

*Based on a national average of 16.5 cents per kWh, running 8 hours daily year-round. Your actual runtime—and cost—depends on your home’s humidity.

That’s the upper bound. In practice, a dehumidifier cycles on and off to hold a target humidity level, so a moderately damp space runs far less than eight hours a day.

ENERGY STAR Units: Worth the Extra Few Dollars?

ENERGY STAR-certified models use more efficient coils, compressors, and fans to remove the same moisture with less energy. That 20% reduction translates directly into lower operating costs—and the label offers a reliable way to compare models without decoding spec sheets.

One caveat: Larger commercial-style units don’t qualify, so the label won’t help for warehouse-sized machines.

When ready to buy, efficiency matters more than bucket size. A smaller, higher-rated unit running more often can beat a larger, inefficient one on energy and performance. If weighing options, check our roundup of the most energy-efficient dehumidifiers for models that clear the ENERGY STAR bar without emptying your wallet.

For official efficiency thresholds and current certification criteria, ENERGY STAR’s key efficiency criteria page is the clearest benchmark.

Three Mistakes That Inflate Your Energy Bill

Most people overspend on dehumidifier electricity without realizing it. Fix these first:

• Oversizing the unit. A dehumidifier too big for the room cycles constantly, wasting energy and failing to stabilize humidity. Match capacity to the space, not the biggest sale.
• Running it colder than needed. Dehumidifiers work best at normal room temperatures. In a cold basement, the unit works harder and less efficiently—a small space heater or whole-home unit designed for cooler spaces fixes this.
• Blocking airflow. Units need clearance around intake and exhaust. Tucked behind boxes, a dehumidifier runs longer to do the same job.

Set target humidity between 40% and 50%, keep the filter clean, and let the built-in humidistat run rather than a manual timer. Those habits cut runtime—and your bill—more than any brand upgrade.

FAQs

Is it cheaper to run a dehumidifier or an air conditioner?

For removing moisture specifically, a dehumidifier is usually cheaper because it’s designed only for that job, drawing 300–700 watts versus 2,000+ for a window AC. Air conditioners remove some humidity but cool as a side effect, which you may not want in a storage space.

Should I run my dehumidifier all day?

Not necessarily. Continuous running wastes electricity once you hit your target humidity. Most units have a built-in humidistat that cycles the compressor to hold 40–50% relative humidity, naturally limiting runtime and energy use.

Can a dehumidifier increase my electric bill noticeably?

A large unit running daily can add $60–90 a year at average rates—noticeable but modest next to heating and cooling. The bigger risk is a poorly sized or malfunctioning unit running constantly, which can double that estimate. Choosing an ENERGY STAR model and letting the humidistat work keeps impact minimal.