Electricity cost of running a basement dehumidifier

A basement dehumidifier’s electricity cost depends mainly on its power draw, how many hours it runs, and your utility rate. For a useful estimate, find the unit’s wattage, multiply it by the hours it operates, then multiply that energy use by the price per kilowatt-hour (kWh) on your electric bill.

The basic electricity-cost formula

Use this formula for a daily estimate:

Daily cost = (watts ÷ 1,000) × hours of operation × electricity rate

For a monthly estimate:

Monthly cost = (watts ÷ 1,000) × hours per day × days per month × electricity rate

Your electricity rate is usually listed on your utility bill as dollars per kWh. Use the total energy charge when possible, not just a fixed monthly service fee that would apply whether the dehumidifier runs or not.

Example calculation

Suppose a dehumidifier draws 500 watts, runs for an average of 8 hours per day, and your electricity rate is $0.18 per kWh:

(500 ÷ 1,000) × 8 × $0.18 = $0.72 per day

Over 30 days, that is approximately:

$0.72 × 30 = $21.60 per month

This is an example, not a universal cost. The actual result can be much lower if the compressor cycles off frequently or much higher if the unit runs nearly continuously.

How much does a basement dehumidifier cost per month?

The following examples show how runtime affects cost. They assume an electricity rate of $0.18 per kWh and are intended for comparison only.

A unit that runs continuously is not necessarily defective, especially during a humid period or when the basement has a moisture problem. However, continuous operation can make the electricity cost substantial and may indicate that the space needs better air sealing, drainage, ventilation, or a larger dehumidifier.

How to find your dehumidifier’s wattage

Check the rating label, owner’s manual, or manufacturer’s specifications for one of these values:

• Watts (W): Use this number directly in the formula.
• Amps (A): If only amps are listed, watts can be roughly estimated as amps multiplied by volts. Household equipment in the United States commonly uses approximately 120 volts, but the rating label or manual should take priority.
• Energy factor or integrated energy factor: This helps compare efficiency, but it does not directly tell you the exact cost in your basement because runtime and moisture load vary.

The rated wattage is usually the running draw, not a guarantee that the appliance consumes that amount every minute. A compressor dehumidifier may cycle on and off after reaching the humidity setting, so its average consumption can be lower than its listed running wattage.

What determines the actual cost?

Humidity level and moisture load

A damp basement, water intrusion, wet concrete, poor drainage, or humid air entering through cracks can keep the dehumidifier running for long periods. Once the moisture source is addressed, runtime may fall significantly.

Temperature

Most compressor-style dehumidifiers remove moisture less effectively in cold basements. Some may run for a long time while collecting relatively little water, and frost can form on the coils. Follow the manufacturer’s specified operating-temperature range. A low-temperature or desiccant model may be more appropriate for a consistently cold space, but its energy use and performance should be compared using the manufacturer’s specifications.

Humidity setting

A very low target humidity makes the unit run more often. For many basements, a setting around 45% to 55% relative humidity is a practical starting range, but use a separate hygrometer if you need to verify the actual room humidity. Avoid setting the machine lower than necessary unless you have a specific moisture-control reason.

Air leaks and basement conditions

Open windows, unsealed rim joists, exposed soil, plumbing leaks, and water entering through walls or floors can overwhelm a dehumidifier. The appliance may remove the symptom while using increasing amounts of electricity.

Filter condition and airflow

A dirty filter restricts airflow and can reduce moisture removal. The unit may run longer, frost up, or collect less water. Clean or replace the filter according to the manual, and keep the air intake and exhaust clear.

Drainage setup

A hose connected to a floor drain or a condensate pump does not usually change the dehumidifier’s electrical consumption much. It does, however, prevent the unit from stopping when its bucket fills. If the unit previously stopped because of a full bucket, continuous drainage can increase total operating hours and therefore increase the bill.

How to reduce a basement dehumidifier’s electricity cost

1. Set a reasonable humidity target. Start near 50% relative humidity and adjust based on condensation, odors, and stored materials.
2. Clean the air filter. Restricted airflow can make the unit run longer and may cause icing.
3. Keep doors and windows closed while it operates. Bringing in humid outdoor air increases the moisture load.
4. Address water entry. Check gutters, downspouts, grading, plumbing, foundation seepage, and condensation on cold pipes.
5. Seal obvious air leaks. Weatherstripping, door sweeps, and appropriate basement air sealing can reduce humid-air infiltration.
6. Leave clearance around the appliance. Follow the manual’s clearance requirements so air can circulate properly.
7. Use a drain hose when practical. This avoids bucket interruptions, although it will not reduce the dehumidifier’s power draw by itself.
8. Compare actual energy use. A plug-in energy monitor rated for the appliance’s electrical load can show how many kWh the unit consumes over a day or week. Follow the monitor instructions and do not use a device that is unsuitable for the dehumidifier’s plug or load.

How to tell whether replacement is worthwhile

Replacing a dehumidifier may make sense when an older unit runs almost constantly, removes little water, repeatedly freezes, leaks refrigerant, or needs an expensive repair. Before replacing it, clean the filter, check for blocked airflow, confirm the room temperature is within the operating range, and verify that the humidity control is working correctly.

If the basement has a continuing water problem, a more efficient dehumidifier alone may not solve the cost issue. Correcting the moisture source is often more effective than buying a larger unit. For electrical faults, refrigerant leaks, damaged wiring, or compressor problems, unplug the appliance and follow the manufacturer’s service guidance or contact a qualified appliance technician.

A quick way to estimate your own cost

Gather these three numbers:

• Dehumidifier wattage
• Average hours of operation per day
• Electricity rate per kWh

Then calculate:

(watts ÷ 1,000) × hours per day × 30 × dollars per kWh

For the most accurate estimate, measure the unit’s actual kWh consumption over several days with a suitable energy monitor. Measure during a typical weather period, since summer humidity and unusually wet conditions can produce very different results from a dry winter month.

Related guides

• Dehumidifier for a 1000 sq ft basement
• 50 pint dehumidifier for a damp garage