About the Dehumidifier Energy Cost
Dehumidifiers often run for months at a stretch during humid seasons, and their electricity draw is easy to underestimate since it is not obvious from the appliance's capacity rating alone. This calculator estimates the annual electricity cost of running a dehumidifier based on its moisture-removal capacity, daily runtime, and how many days per year it actually operates.
How It Works
You enter the dehumidifier's capacity in pints removed per day, hours run per day, days run per year, and your electricity rate. The calculator estimates power draw using a rule-of-thumb figure of 6 watts per pint-per-day of rated capacity, converts that wattage into kWh based on your entered runtime, and multiplies by your electricity rate to produce an annual cost figure alongside the estimated annual energy use and power draw.
Examples
Basement dehumidifier, seasonal use
At 50 pints per day capacity, 10 hours per day, 120 days per year, and $0.16 per kWh, estimated wattage is 50 x 6 = 300 watts, giving 0.3 x 10 x 120 = 360 kWh and about $58 per year.
Smaller unit, near-continuous use
At 30 pints per day capacity, 16 hours per day, 200 days per year, and $0.18 per kWh, estimated wattage is 30 x 6 = 180 watts, giving 0.18 x 16 x 200 = 576 kWh and about $104 per year.
Advantages
- It translates a capacity rating that is hard to connect to an electricity bill into an actual estimated annual cost figure in dollars.
- It lets you compare different runtime scenarios, such as seasonal basement use against near year-round operation, using the same capacity input as a starting point.
- It is useful for evaluating whether a larger, faster-running unit or a smaller, longer-running unit ends up costing less overall for a given space and humidity load.
Common Mistakes
- Using the dehumidifier's maximum rated capacity when the unit actually runs at a lower setting most of the time, which overstates the estimated wattage.
- Entering hours-per-day as if the unit runs continuously at full power, when most dehumidifiers cycle off automatically once the target humidity level is reached.
- Comparing two different units by capacity alone without factoring in how many hours or days each would actually need to run to keep a given space at its target humidity.
Edge Cases to Watch For
- The 6 watts per pint-per-day figure is calibrated to ENERGY STAR certified units, and older or non-certified dehumidifiers can draw meaningfully more power for the same rated capacity, which would understate the actual cost.
- A dehumidifier's real-world runtime often is not constant, since most units cycle on and off once they reach a target humidity level, so entering hours-run-per-day as if it were continuous full-power operation may overstate energy use compared to how the unit actually behaves.
- A correctly sized unit for the space may also run fewer hours per day than an undersized unit working to dehumidify the same room, so capacity and hours-per-day are best considered together rather than as independent choices.
Common Use Cases
- Homeowners with a damp basement or crawlspace deciding whether a dehumidifier's ongoing running cost fits their household budget.
- Renters or landlords estimating the added electricity cost before installing a dehumidifier in a rental unit.
- Buyers comparing the total cost of ownership between differently sized dehumidifier models being considered for the same space.