What a Crawl Space Dehumidifier Costs to Run Per Year

Most running-cost figures you’ll find are estimates wearing a lab coat

A crawl space dehumidifier runs for months at a time, so its electricity cost matters more than its sticker price over any reasonable ownership period. That makes it the number people search for, and the number the fewest sources can actually support.

Of the seventeen products in our catalog, three have a running cost we can verify: the AprilAire E080, E100 and E130. For the rest, the manufacturer has not published the figure a cost calculation requires, and we would rather leave a gap than fill it convincingly.

Where a verifiable number comes from

The AprilAire E-series is ENERGY STAR certified, and the EPA’s certified dehumidifiers registry publishes a DOE-measured annual energy consumption for each certified model. That measurement comes from a standardized test procedure, not from a manufacturer’s marketing sheet, and it is expressed as kilowatt-hours per year — exactly the unit an electricity bill is denominated in.

That makes the arithmetic trivial and, more importantly, honest:

annual cost = measured kWh/year × your electricity rate

No duty cycle to assume, no run-hours to guess, no seasonal adjustment to argue about. The test already accounts for cycling, because it measures a year of operation rather than a moment of it.

The three numbers we can stand behind

At our default rate of $0.16/kWh, using the registry’s measured figures:

All three carry an Integrated Energy Factor of 2.35 L/kWh and DOE capacities of 65, 85 and 105 pints/day respectively. Note that the DOE capacity is lower than the AHAM capacity in each unit’s name — different test conditions, both published, neither wrong.

Set those three against the commercial units we also cover, and the shape of the problem is clearer than any paragraph makes it:

The blank rows are the honest part. They are not zeros and they are not small numbers — they are units for which no measured figure exists to publish.

The pattern worth noticing is that the E130 removes roughly 60% more water per day than the E080 for about 46% more energy per year. Within one product line, the larger unit is not proportionally more expensive to run, because a unit with headroom spends more of the year cycled off.

Why the commercial units carry no figure at all

The AlorAir Sentinel HD55, HDi90 and HDi100, the AlorAir Storm LGR Extreme, and the BaseAire AirWerx units are not ENERGY STAR listed. The programme doesn’t cover commercial equipment, so the registry has no measured energy figure for any of them, and neither do we.

Only one of them publishes rated wattage: the Sentinel HDi90 at 293 W. For that single unit we can produce a wattage-based estimate, using a stated method — rated watts, twelve assumed active hours a day to reflect compressor cycling, across the months the unit runs, times your rate. That is an estimate with its assumptions on the table, and we label it as one wherever it appears.

For the others, the spec sheets give amperage and stop: 4.1 A for the HD55, 6.82 A for the HDi100, 5.62 A for the Storm LGR Extreme.

Volts × amps is not watts, and this is where cost pages go wrong

It is tempting to turn amperage into wattage by multiplying by 115 or 120 volts. The result looks like a wattage, sits neatly in a table, and is wrong.

That product is apparent power, measured in volt-amperes. A dehumidifier’s compressor is an inductive load, so its real power draw — the thing your meter bills you for — is lower than its apparent power by a power factor the manufacturer doesn’t publish. Multiplying amps by volts and calling the answer watts overstates consumption by an unknown margin, in a direction that always flatters the arithmetic.

We were offered exactly these figures for the AlorAir and BaseAire units during research and declined to enter them. A cost table with a fabricated number in it is worse than a cost table with a blank, because the blank tells you the truth about what is known.

Comparing a measured figure to an estimated one

One caution that applies directly to the numbers above. The AprilAire costs are full-year measured figures. The HDi90 estimate is a seasonal wattage-based estimate over the months you choose to run it. They are computed on different bases, so setting them side by side and declaring one unit cheaper is not a comparison — it is two different questions with a dollar sign in front of each.

Compare measured to measured, or estimate to estimate, and treat cross-basis comparisons as unreliable.

Your electricity rate moves the answer more than your unit does

Take the E100’s measured 821 kWh/year and change nothing but geography:

The state rates and the national average come from Electric Choice’s 2026 state-level reporting derived from EIA data, which also records that U.S. residential rates rose roughly 17% over four years, from 15.04¢/kWh in 2022 to 18.83¢/kWh in 2026.

The same dehumidifier costs nearly four times as much to run in Hawaii as in North Dakota. Any article quoting a single national running cost for a dehumidifier is telling you about its own assumptions rather than about your bill. Our operating cost calculator takes your state’s rate instead of averaging it away.

What published cost guides report, and how to place it

Aggregated cost guides report monthly running costs for residential-scale dehumidifiers commonly falling in the $10–$30/month range, with one cited example of a 30-pint unit at roughly $17–18/month against a 120-pint unit at over $36/month. The same sources report homeowners seeing an estimated $300–$500 annual electricity bill increase from running a dehumidifier, and note that ENERGY STAR-certified units cost more upfront while reducing long-run operating cost.

Those are third-party aggregate estimates across unspecified units, climates and rates — not measurements of any product in this catalog. They are a useful sanity check on the order of magnitude, and the E080’s measured $101/year at $0.16/kWh sits comfortably inside the low end of that range. They are not a substitute for a figure tied to a specific model.

Working out your own number

If your unit is ENERGY STAR certified, look up its measured annual kWh in the EPA registry and multiply by the rate on your own bill — not a national average, since the spread above shows what that costs you in accuracy.

If it isn’t certified, check whether the manufacturer publishes rated wattage. If it does, a wattage-and-run-hours estimate is defensible as long as you state the duty-cycle assumption. If it publishes only amperage, you cannot get to a real cost from published data, and no amount of arithmetic will change that.

The last variable is one no spec sheet controls: a correctly sized unit in a sealed crawl space cycles off for much of the year, while an undersized one in a vented space runs closer to continuously. Sizing and running cost are the same decision approached from two directions.