What will running a dehumidifier actually cost?
Anyone who’s dealt with a damp basement knows the routine: the bucket fills, the machine hums along, and you start wondering what this is doing to the electric bill.
I’ve always enjoyed helping people figure out everyday problems. Teaching was my job for 24 years. These days I build small tools like this one, hopefully saving somebody a headache.
Let’s estimate the running cost, then figure out how you’ll get the water out without emptying a bucket twice a day.
Estimate your cost and drainage needs
If you already own a unit, look for its watt rating. If you’re shopping, enter the running watts from a model’s published specifications. No need to guess an Amazon price.
The surprisingly important question: where will the water go?
Two dehumidifiers can have similar moisture-removal ratings, yet be completely different to live with. If you’re emptying the bucket by hand, the size of the tank matters almost as much as how well the machine dries the air. A unit that switches off when the bucket is full won’t keep drying the room while you’re away.
Gravity drain: If there’s a suitable floor drain below the outlet, a maker-approved hose may carry water away without an electric pump. You still need to follow the unit’s directions for hose slope, secure drainage and preventing backflow. Don’t assume every model has a continuous-drain port.
Pump: If water must travel upward to a sink or elevated drain, look for a model with a built-in pump, or a compatible condensate pump with appropriate safety features. Follow the manufacturer’s limits for lift height and hose routing. Never improvise an electrical pump near standing water.
Crawlspace: Temperature, ducting, access, drainage and moisture sources matter more than this simple electric bill tool can decide. Use equipment designed for that environment and qualified installation when needed.
How to calculate dehumidifier electricity cost
Multiply running watts by compressor-hours per day, divide by 1,000 to get kilowatt-hours, then multiply by your electric rate. I use 30.4 days for an average month. An estimated active-season cost is the average monthly cost times the number of months you’ll use it.
Example: 500 watts for 10 hours each day uses about 5 kWh a day. At an entered rate of $0.18 per kWh, that works out to about $0.90 per day. That’s your example energy estimate, not the price of a machine or a guarantee of actual use.
Here’s the catch: dehumidifiers cycle, temperatures change, filters get dirty, and humidity loads change. Entering the wattage from a label and saying it runs all day can overstate the actual compressor use. A plug-in energy meter can give you a more realistic average where it’s safe and approved for the unit’s load.
When buying a bigger dehumidifier isn’t the answer
If water is coming through the basement wall or pooling on the floor, first deal with the leak and drainage. A larger portable machine can’t solve a structural moisture problem. EPA recommends keeping indoor relative humidity below 60% and, where possible, around 30%–50%. Very dry air can also be uncomfortable.
Check the temperature of the space. ENERGY STAR notes that some conventional units lose effectiveness in spaces below 65°F as frost can form on coils. Cold basements may call for a unit specified for lower operating temperatures.
This calculator does not claim to tell you an exact pint-per-day size for your room. Moisture entry, construction, temperature and ventilation can change the load dramatically. For a persistent damp crawlspace or large basement, check qualified sizing guidance and the exact manufacturer specifications.
What kind of unit should you shop for?
If you have a low floor drain, I’d look for continuous drainage. If you must send water upward, search for the pump feature by name. The links below browse Amazon categories, not verified individual matches.
As an Amazon Associate I earn from qualifying purchases. The calculator is free. Optional affiliate links may help support this retirement project.
Common dehumidifier buying questions
How much does a dehumidifier cost to run 24 hours a day?
You need its actual average power draw and your utility rate. A unit that’s plugged in for 24 hours may run its compressor only part of that time. Use the wattage × hours × electric-rate calculation to estimate cost, then measure real consumption when possible.
Can I drain a dehumidifier into a sink?
Possibly, but only with equipment designed for the height and route. A simple gravity hose cannot push water uphill. A compatible condensate pump or built-in pump may be needed, with proper installation and overflow protection.
Do I need a dehumidifier with a pump?
Only if your drainage route needs one. If you can safely direct water into a lower drain using the maker’s approved hose, gravity may be simpler and involve fewer moving parts.
Is a 50-pint unit always better than a 35-pint unit?
No. Compare ratings under the same current test conditions, temperature limits, integrated energy factor, noise, tank capacity and drainage setup. Bigger isn’t automatically better for the room.
Sources: EPA moisture guidance and ENERGY STAR dehumidifier buying guidance.