Cost to Run a Dehumidifier: Watts, Hours and Real Examples
The cost to run a dehumidifier typically falls somewhere around $5 to $40 a month for a portable unit, depending on its wattage, how many hours the compressor actually runs and your electricity rate, while a large whole-home or crawl space unit running hard in a damp space can cost more. The quick formula is watts multiplied by hours of run time, divided by 1,000 to get kilowatt-hours, multiplied by your price per kilowatt-hour. Those monthly figures are typical illustrative ranges, not measurements of any particular model, and your own bill can be calculated in a few minutes using the steps below. This guide walks through the calculation with worked examples, shows how the efficiency rating ENERGY STAR uses changes the answer, explains why a humidistat matters more than the sticker wattage, covers upfront equipment and installation costs, and lays out when a portable unit is enough and when to call a professional. Front Range details such as cool basements and a short damp season are included where they change the numbers.
Part of our Humidity Control guide — start there for the full picture →
Cost to Run a Dehumidifier at a Glance
The table below uses an example electricity rate of $0.15 per kWh and example wattages typical of each size class. Both are illustrative. Check the label on your unit and the rate on your utility bill for your own numbers.
| Unit type (example wattage) | Hours running per day (example) | Example kWh per day | Example cost per day | Example cost per 30 days |
|---|---|---|---|---|
| Small portable (300 W) | 8 | 2.4 | $0.36 | About $11 |
| Mid-size portable (450 W) | 10 | 4.5 | $0.68 | About $20 |
| Large portable (600 W) | 12 | 7.2 | $1.08 | About $32 |
| Whole-home or crawl space unit (700 W) | 12 | 8.4 | $1.26 | About $38 |
| Large portable in a very wet space (600 W) | 24 | 14.4 | $2.16 | About $65 |
The last row shows why run time matters so much. A dehumidifier left to run around the clock in a space with an unsolved water problem can cost several times more than the same unit cycling on a humidistat in a basement that is only mildly damp. The wattage on the label sets the ceiling; the hours determine the bill.
If you are shopping for a new unit, our roundup of the best dehumidifiers compares current models by capacity and features.
How to Calculate Your Own Running Cost
The method is the same for any electrical appliance. It takes four numbers.
- Find the wattage. Look on the nameplate or in the manual. If only amps and volts are listed, multiply them (amps × volts = watts) for an approximate maximum draw. The actual running draw is often somewhat lower than the nameplate maximum.
- Estimate run hours. Count the hours the compressor actually runs, not the hours the unit is switched on. With a humidistat, the unit cycles off once the target humidity is reached, so run hours are often well below 24 even when the machine is “on” all day.
- Convert to kilowatt-hours. Multiply watts by hours, then divide by 1,000.
- Multiply by your rate. Use the price per kWh on your electric bill, including delivery charges if your utility bills them per kWh.
Worked example
This is an example to show the arithmetic, not a measurement of any specific model or utility rate.
- Example unit draw: 500 watts
- Example compressor run time: 10 hours per day
- 500 W × 10 h = 5,000 watt-hours = 5.0 kWh per day
- Example rate: $0.15 per kWh
- 5.0 kWh × $0.15 = $0.75 per day
- $0.75 × 30 days = $22.50 per month
- Over a four-month damp season, about $90
Change any input and the result scales directly. Doubling the run time doubles the cost; cutting the rate in half halves it. If your utility uses time-of-use pricing, run hours during off-peak periods cost less, and some units have timers that make this easy.
For context on how a dehumidifier compares with the rest of your household’s electricity use, our guide to how many watts a house uses covers typical appliance loads.
Measuring instead of estimating
For the most accurate number, plug the unit into an inexpensive plug-in energy meter for a week. The meter records actual kilowatt-hours, which captures cycling, fan-only time and defrost periods that estimates miss. Divide the weekly reading by seven and multiply by your rate for a daily cost. This works for portable units on a standard outlet; hardwired whole-home units need a different approach, such as reading a circuit-level energy monitor if the home has one.
Annual cost by use pattern
Monthly figures are useful, but the yearly total is what most budgets care about, and it depends heavily on how many months the unit actually works. The examples below keep the same illustrative 500-watt unit and $0.15 per kWh rate and change only the use pattern.
| Use pattern (example) | Run hours per day | Months per year | Example annual cost |
|---|---|---|---|
| Mildly damp basement, summer only | 6 | 3 | About $40 |
| Damp basement, spring through early fall | 10 | 5 | About $113 |
| Wet crawl space or basement with an unresolved leak | 20 | 8 | About $360 |
The arithmetic for the middle row is 500 W × 10 hours = 5 kWh per day, × $0.15 = $0.75 per day, × roughly 150 days = about $113. The gap between the first and last rows has little to do with the machine and almost everything to do with the space. That is why fixing a drainage or leak problem is usually the most effective way to lower a dehumidifier bill.
Two smaller loads are worth knowing about. Many units keep the fan running after the compressor stops, and some draw a little standby power while idle. Both are modest compared with compressor run time, but an energy meter will capture them if you want the full picture.
Efficiency: Why ENERGY STAR Models Cost Less to Run
Two units with the same capacity can use noticeably different amounts of electricity. ENERGY STAR states that a certified dehumidifier uses more efficient refrigeration coils, compressors and fans to remove the same amount of moisture as a similarly sized conventional unit while using 20 percent less energy. Certified models are available as both portable and whole-home units.
Integrated Energy Factor (IEF)
ENERGY STAR explains that dehumidifier efficiency is measured by the integrated energy factor, expressed in liters of water removed per kilowatt-hour of energy consumed (L/kWh). A higher integrated energy factor generally means a more efficient dehumidifier. This rating offers a second way to estimate running cost, based on how much water you are actually removing.
Worked example using IEF (figures are illustrative):
- Water removed per day: 25 pints, which is about 11.8 liters (1 pint ≈ 0.473 liters)
- Unit A, example IEF 1.6 L/kWh: 11.8 ÷ 1.6 ≈ 7.4 kWh per day
- Unit B, example IEF 2.0 L/kWh: 11.8 ÷ 2.0 ≈ 5.9 kWh per day
- At an example $0.15 per kWh, that is roughly $1.11 versus $0.89 per day
Over a 120-day season in that example, the more efficient unit would save roughly $26. The gap grows in damper spaces and with longer seasons. Compare IEF on the yellow EnergyGuide label or product specifications when shopping, and use the ENERGY STAR product finder to check whether a model is certified. ENERGY STAR also recognizes a “Most Efficient” tier for the top-performing models each year.
Capacity and sizing affect cost too
An undersized dehumidifier runs constantly and may never reach the target humidity, which wastes energy. ENERGY STAR notes it is better to oversize than undersize, and provides a sizing chart based on room size and conditions. For a small-to-medium space that is slightly to moderately damp at 50 to 75 percent relative humidity, its chart suggests roughly 20 to 30 pints per day; very damp spaces at 75 to 90 percent call for 25 to 40 pints; wet spaces with sweating walls or seepage call for 30 to 50 pints. Larger spaces need more. Our guide on how to choose a dehumidifier walks through sizing in more detail.
The Humidistat: The Biggest Lever on Your Bill
The setting you choose matters more than almost anything else. ENERGY STAR notes that all certified dehumidifiers include a built-in humidistat, which lets you set a target relative humidity; once the room reaches that level, the unit cycles on and off to maintain it.
What target to use? ENERGY STAR states the optimum relative humidity for a building is generally considered to be between 30 and 50 percent, and that levels above that may promote mold growth. The EPA advises keeping indoor humidity below 60 percent, ideally between 30 and 50 percent. The CDC advises keeping humidity no higher than 50 percent. Setting the humidistat far below what you need, such as 30 percent in a summer basement, makes the unit run much longer for little benefit.
Practical settings that keep running costs down:
- Set the humidistat around 45 to 50 percent for most basements and living spaces, and adjust based on a separate hygrometer reading.
- Close doors and windows to the space while the unit runs, as ENERGY STAR advises, so it is not drying the outdoors.
- Keep the unit away from walls and furniture unless it has top-mounted discharge, so air circulates freely.
- Clean the filter regularly. A clogged filter reduces airflow and efficiency.
- Use continuous drainage to a floor drain or sump where possible, so the unit does not stop when the bucket fills and then work harder to catch up.
How quickly a space dries also affects how many hours you pay for. Our guide to how long a dehumidifier takes to work covers what to expect in the first days of running a unit.
Upfront Costs: Equipment and Installation
Running cost is only part of the picture. The table shows typical upfront ranges by unit type. These are typical national ranges for budgeting, not quotes.
| Unit type | Typical equipment range | Typical installation | Typical upkeep |
|---|---|---|---|
| Portable (20–50 pint) | $150–$400 | None; plug in | Filter cleaning; occasional replacement unit every several years |
| Portable with built-in pump | $250–$500 | None; route the hose | Pump and hose checks |
| Crawl space or basement standalone (high capacity) | $1,000–$2,500 | $300–$1,500+ | Filter changes, drain checks, periodic service |
| Whole-home, ducted into HVAC | $1,200–$2,500 | Often similar to equipment cost; varies with ductwork | Filter changes; service with HVAC visits |
Crawl space units often come bundled with encapsulation work, which raises the total. Our guide to crawl space dehumidifier cost breaks down those projects.
ENERGY STAR describes whole-home dehumidifiers as potentially expensive but beneficial for relatively well-sealed homes with central air systems that see humidity readings consistently above 55 percent throughout the house. It also notes that home sealing and duct sealing improve performance and reduce energy use, and that regular heating and cooling maintenance helps keep the system working.
Front Range Considerations
Much of the Colorado Front Range is dry for most of the year, which changes the running-cost picture compared with humid regions.
- Shorter damp season. Many Front Range homes need a dehumidifier only in specific spaces and seasons, such as a basement during late spring rains or summer thunderstorm periods. Fewer months of operation means a lower annual cost than national averages suggest.
- Winter humidity is usually low. ENERGY STAR notes that in colder climates during the heating season, humidity should be in the range of 30 to 40 percent to prevent window condensation. Most Front Range homes are already that dry or drier in winter, so a dehumidifier typically has little to do then. Turn it off or let the humidistat keep it idle.
- Cool basements. ENERGY STAR notes that frost can form on the coils if air temperature drops below 65 degrees F, causing the compressor to cycle without removing moisture. In a cool basement, look for a model rated for low-temperature operation or with an anti-frost sensor, or the unit may run longer and accomplish less.
- Source control first. When a Front Range basement is damp, the cause is often drainage: downspouts, grading or a sump issue. ENERGY STAR lists extending downspouts, keeping gutters clear and sloping soil away from the foundation among ways to reduce the need for dehumidification. Fixing the source can cut run hours more than any efficiency upgrade.
For basement-specific advice, see our guide to choosing a dehumidifier for the basement. The heating and cooling hub gathers related HVAC and ventilation guides.
DIY vs Hiring a Pro
Portable dehumidifiers are a simple homeowner purchase. Choose the right capacity, plug the unit into a properly grounded outlet as ENERGY STAR advises, set the humidistat and arrange drainage. ENERGY STAR also advises keeping drain hoses away from electrical cords and connections, and never setting up drainage near electrical circuits or devices.
A professional makes sense when:
- You are considering a whole-home unit tied into ductwork. ENERGY STAR notes most whole-home units are equipped only with a drain that should be routed to a floor drain or condensate pump by an HVAC professional during installation.
- A crawl space needs a dehumidifier along with vapor barrier or encapsulation work.
- Humidity stays high despite a correctly sized unit, which suggests a water intrusion problem.
- You see signs of mold, water staining or persistent musty odors.
How to Get Fair Quotes for Installed Systems
For portable units, comparing price, capacity and IEF online is usually enough. For installed whole-home or crawl space systems, quotes vary widely, so a few steps help.
- Measure first. Record humidity readings with a hygrometer over a week or two so you know the actual problem and can tell whether quotes are sized sensibly.
- Get at least three written quotes. Ask for the make and model, rated capacity, efficiency rating, drainage plan and any electrical work.
- Ask about the cause. A good contractor should ask where the moisture comes from, not just sell a larger unit. Ask what drainage or sealing work would reduce the load.
- Separate bundled work. Encapsulation, sump pumps and dehumidifiers are often sold together. Ask for line-item pricing so you can compare.
- Confirm warranty and service. Get equipment and labor warranty terms in writing, and the cost of filters or annual service.
When to Call a Pro or an Inspector
If a dehumidifier runs constantly and humidity stays above about 60 percent, the space likely has a moisture source that needs attention. The EPA’s guidance on mold and moisture stresses fixing water problems promptly and drying wet materials quickly. Signs such as efflorescence on foundation walls, water stains, condensation on cold pipes or a persistent musty smell are worth a professional look.
If you are buying a Front Range home with a damp basement or crawl space, contact our team to connect with a qualified local inspector who can look for moisture sources before you commit.
References
- Dehumidifiers: Buying Guidance and Saving Tips — ENERGY STAR
- A Brief Guide to Mold, Moisture and Your Home — U.S. Environmental Protection Agency
- About Mold and Your Health — Centers for Disease Control and Prevention
- ENERGY STAR Most Efficient — ENERGY STAR
Frequently asked questions
How much does it cost to run a dehumidifier per month?
A portable unit typically costs around $5 to $40 a month, depending on wattage, run hours and electricity rate. For example, a 500-watt unit running 10 hours a day at $0.15 per kWh costs about $22.50 a month. Check your unit's label and your utility rate for your own figure.
How do you calculate dehumidifier electricity cost?
Multiply the unit's watts by the hours the compressor runs, divide by 1,000 to get kWh, then multiply by your price per kWh. A plug-in energy meter gives a more accurate reading because it captures cycling and fan-only time.
Do ENERGY STAR dehumidifiers really save money?
ENERGY STAR states certified dehumidifiers remove the same amount of moisture as similar conventional units while using 20 percent less energy. Savings grow with longer seasons and damper spaces.
Is it expensive to run a dehumidifier all day?
It can be if the compressor runs continuously, which may happen in a very wet space or with an undersized unit. With a humidistat set around 45 to 50 percent, most units cycle off once the target is reached, so actual run hours are lower.
What humidity should a dehumidifier be set to?
ENERGY STAR describes 30 to 50 percent relative humidity as generally optimal, and the EPA advises staying below 60 percent, ideally 30 to 50 percent. Setting it far lower than needed raises running cost with little benefit.
Seeing persistent dampness in a basement or crawl space of a home you are buying on the Front Range? Reach out through our contact page to connect with a vetted local inspector.
Dehumidifiers for damp basements
Holding relative humidity under ~50% is the single most effective way to keep mold from taking hold in a basement or crawlspace.
| Product | Why | Buy |
|---|---|---|
 hOmeLabs 50-Pint (7,000 sq ft) | Popular large-basement unit. | Amazon — $269.99 |
 Frigidaire High-Humidity | Continuous-drain option. | Amazon — $303.16 |