How much does it cost to run a dehumidifier?
A dehumidifier actively removes moisture from the air by pulling in humid air, cooling it to extract condensation, and releasing the dried air back into the room. This process runs continuously during damp seasons and consumes significant energy because the compressor and fan operate simultaneously for many hours at a stretch.
Dehumidifier running cost calculator
- Per day
- $0.85
- Per month
- $10.63
- Per year
- $127.50
- CO₂ / year
- 300 kg
Based on 750 kWh per year. Adjust the price per kWh to match your latest electricity bill for an exact figure.
At 500 watts used 10 hours a day, a dehumidifier costs about $0.85 per day, $10.63 per month and $127.50 per year on an average rate of 17¢ per kWh — roughly 750 kWh and 300 kg of CO₂ over a year. Enter your own electricity rate and usage in the calculator above for a figure matched to your bill.
Dehumidifiers differ fundamentally from passive drying methods because they force air through a cold evaporator coil, which requires the compressor to run constantly. The bigger the unit and the lower the target humidity, the longer that compressor stays on. Many people underestimate how long dehumidifiers actually run—you might leave one on for 10 or 12 hours a day without thinking about it, especially in basements or bathrooms where moisture feels endless. The seasonal nature of dehumidifier use (spring through fall, or year-round in very humid climates) means the cumulative hours add up faster than occasional appliances.
Room size and target humidity level drive energy consumption more than any other factors. A dehumidifier sized for a small closet will cycle on and off frequently in a large basement, using less energy overall but failing to control humidity. Conversely, oversizing a unit for a small space wastes energy because it reaches the target humidity quickly and sits idle. The sweet spot is matching capacity to room volume and accepting a reasonable humidity level—aiming for 30 percent relative humidity in a 2,000-square-foot basement is far more expensive than targeting 50 percent. Older units and those without automatic humidity sensors waste energy by running continuously even after moisture levels drop.
The compressor itself accounts for the bulk of energy draw, but the fan that circulates air through the evaporator coil also runs whenever the unit is powered. Some dehumidifiers have a continuous drain option (plumbing to a floor drain or condensate pump) that lets them run unattended, while others require manual bucket emptying, which often leads to shutdown and repeated cycling. Condensate pumps add a small parasitic load, but the time saved by avoiding constant bucket monitoring usually justifies that cost over a season. Placement matters: positioning the dehumidifier where it pulls in the most humid air (near the moisture source) and has clear airflow reduces the hours needed to reach your target humidity.
When shopping for an efficient model, look for units with built-in humidistats that automatically cycle the compressor off once target humidity is reached, rather than running 24/7. Energy Star certified dehumidifiers are independently tested for energy efficiency across standard conditions and deliver measurable savings. Larger capacity units (measured in pints per day) are often more efficient per unit of moisture removed, so a 50-pint model running half the time beats two 25-pint units running full-time. Also check whether the fan continues to run after the compressor shuts off, which can help with air circulation and actually improve efficiency in some cases. Warranty length and component availability matter too, since a unit that fails midseason will be replaced by an even larger energy draw while you're without dehumidification.
Frequently asked questions
- Why does my dehumidifier cost more to run than I expected?
- Dehumidifiers run for extended periods during humid seasons—often 10 or more hours daily—and the compressor draws significant power whenever it cycles on. Many people also run units larger than necessary for their space, or they don't adjust the target humidity setting, so the compressor stays engaged longer than needed. If the unit lacks a humidistat, it may run continuously without stopping, even after the air is dry enough.
- Does the size of the dehumidifier matter for energy use?
- Yes, significantly. A unit that is oversized for your room will reach the target humidity quickly and then sit idle, wasting energy on startup and continuous fan operation. An undersized unit will run almost constantly and still fail to control moisture. The most efficient approach is to match the dehumidifier's capacity to your room size and moisture load. Larger-capacity units tend to be more efficient per pint of moisture extracted, but only if you actually need that capacity.
- Should I run my dehumidifier 24 hours a day during humid months?
- Running continuously wastes energy unless your space is extremely damp. A dehumidifier with an automatic humidistat will cycle the compressor on and off as needed to maintain your target humidity level, using far less energy than constant operation. Set a reasonable target—around 45 to 55 percent relative humidity is comfortable and healthy for most spaces—and let the unit manage itself rather than forcing it to run all day and night.
- What is the difference between Energy Star and standard dehumidifiers in terms of energy use?
- Energy Star certified dehumidifiers are tested under standardized conditions and must meet efficiency thresholds set by the EPA. They typically use 15 to 25 percent less energy than non-certified models to remove the same amount of moisture. The difference compounds over a season; a more efficient unit running for 150 days can save significantly compared to a standard model, especially if you plan to use the dehumidifier for many years.
- Does a continuous drain or condensate pump change how much energy the dehumidifier uses?
- A continuous drain option itself does not increase energy use, but a condensate pump adds a small parasitic load. The real benefit of automatic drainage is that you're not stopping and restarting the dehumidifier to empty buckets, which avoids repeated cycling and lets the unit maintain consistent operation toward your humidity target. Over a season, avoiding frequent manual emptying and the interruptions it causes usually results in less total energy consumption despite the pump's minor draw.
- Where should I place my dehumidifier to minimize how long it needs to run?
- Position the dehumidifier where the air is most humid and where it has unobstructed airflow—typically near the source of moisture (a damp corner, bathroom, or basement wall) and away from walls, furniture, or doors that block circulation. Proper placement allows the unit to pull in the wettest air directly, dry it efficiently, and distribute the dried air throughout the room, reducing the overall runtime needed to reach your target humidity.