How much does it cost to operate a dehumidifier and energy consumption
Why it pays to know the operating costs of a dehumidifier
When choosing an air dehumidifier, customers usually focus on the purchase price and the dehumidification performance expressed in liters per 24 hours. Operating costs, i.e., how much the device actually costs in electricity during weeks, months or years of use, are often overlooked. Yet it is precisely this figure that determines whether an investment in a higher quality and more efficient device will pay off, or whether a cheaper model will end up being more expensive. From our experience in sales and service, we know that differences between various types and models of dehumidifiers in energy consumption can be several times higher at the same declared dehumidification performance. In this article, we will in detail examine what the consumption consists of, how to calculate it, what the real monthly and annual costs are in typical usage scenarios (apartment, basement, pool, building drying), and how to reduce operating costs without sacrificing comfort or dehumidification efficiency.
What determines the energy consumption of a dehumidifier
The electricity consumption of a dehumidifier does not depend only on the number stated on the energy label or in the technical specifications. Real consumption is a product of several factors - the nominal power of the compressor and fan, the actual running time of the compressor during the day, external conditions (temperature and relative air humidity in the room), and not least, the construction type of the device.
Power vs. actual consumption
The power stated by the manufacturer (e.g., 200 W, 350 W or 550 W) is the value drawn from the grid at the moment when the compressor and fan are running at full power. Most condensation-type dehumidifiers, however, do not run continuously - they are controlled by a built-in hygrostat, which turns off the compressor once the set target humidity is reached and turns it on again only when the humidity rises above the threshold. This means that the actual daily consumption is always lower than the theoretical maximum calculated as power multiplied by 24 hours. When calculating costs, it is therefore crucial to estimate the real share of compressor running time, not just multiply the nominal power by the whole day.
Condensation vs. adsorption principle and consumption
Condensation dehumidifiers (including those from the Secco range) work on the principle of a cooling circuit - air is cooled below the dew point on a cold heat exchanger, water vapor condenses into droplets and drains into a tank or through a hose, and the air is then slightly heated on the condenser and returned to the room. This principle is very energy efficient at room temperatures of approximately 15 to 32 °C, where it can extract up to 2 to 4 liters of water from one kilowatt-hour.
Adsorption (sorption) dehumidifiers work differently - air passes through a rotor impregnated with a hygroscopic material (silica gel), which absorbs moisture, and the moisture is then released using electric heating into a smaller air stream, which is either vented outside or condensed on a smaller heat exchanger. Heating is energy-intensive, so adsorption devices have a lower dehumidification factor (fewer liters of water per kilowatt-hour) at normal room temperatures than condensation devices. Their advantage becomes apparent only at low temperatures (below 10-12 °C), where condensation devices lose performance and efficiency, while adsorption devices operate almost independently of temperature. More detailed differences between the two principles are discussed in a separate article: Condensation vs. adsorption dehumidifier - differences and comparison.
Dehumidification factor - a better indicator than power alone
When comparing the operating costs of different models, it is more appropriate to track the so-called dehumidification factor, i.e., the ratio of liters of water removed per kilowatt-hour of energy consumed (l/kWh). This data can be found in the technical documentation of higher quality models. The higher the number, the more efficient the device operates. Common domestic condensation dehumidifiers achieve a factor of approximately 1.5 to 2.5 l/kWh, while more powerful and modern models with more efficient compressors can reach 3 to 4 l/kWh. Adsorption devices operate in the range of 0.5 to 1.5 l/kWh at room temperature, which in practice means significantly higher consumption to remove the same amount of water compared to condensation solutions - unless we are talking about cold rooms, where the ratio is the opposite.
How to calculate operating costs - formula and procedure
Calculating the operating costs of a dehumidifier is not complicated, provided we know four basic inputs: the nominal power of the device in watts, the estimated average number of hours of actual compressor operation per day, the current electricity price per kilowatt-hour, and the number of days the device will be in operation.
The formula looks like this: daily consumption (kWh) = power (W) / 1000 × hours of actual operation. Then daily costs (EUR) = daily consumption (kWh) × electricity price (EUR/kWh). Monthly costs are obtained by multiplying by the number of operating days in a given month, and annual costs by multiplying by the number of days the device actually operates during the year (e.g., only during the heating season, or on the contrary, year-round for a swimming pool).
In the calculations in this article, we use an average electricity price in Slovakia in the range of 0.15 to 0.25 EUR/kWh, which corresponds to typical household tariffs in 2024. If you have your own tariff, simply substitute your value - the calculation principle remains the same.
Concrete examples from practice
The following scenarios are based on common customer orders and inquiries that we encounter most frequently in practice. These are approximate values - the exact power consumption of a specific model is always found in its technical specifications.
Example 1 - 60 m² apartment, normal humidity increase
A smaller home dehumidifier such as SECCO 11l/24h or SECCOASCIUTTO EL 12l/24h has a typical power consumption of around 150-190 W. With normal use in an apartment, where humidity fluctuates and the hygrostat regularly turns off the compressor, the actual running time of the compressor is around 5 to 7 hours per day. At 170 W and 6 hours of operation, the daily consumption is 1.02 kWh. At a price of 0.20 EUR/kWh, this amounts to 0.20 EUR per day, approximately 6.1 EUR per month (30 days), and around 30 EUR per season with seasonal use during approximately 5 months (autumn to spring, about 150 days).
Example 2 - cellar or garage with year-round operation
With a larger device such as SECCOPROF 28l/24h, with a power consumption of around 350-400 W, which operates more intensively in a cellar due to constantly higher humidity (average compressor running time of 9-10 hours per day), the daily consumption is approximately 3.5-4 kWh. At a price of 0.20 EUR/kWh, this means 0.7-0.8 EUR per day, 21-24 EUR per month, and approximately 255-290 EUR per year with year-round operation (365 days). This is a typical scenario where it is worth considering a more efficient model with a higher dehumidification factor, as the difference in annual costs between an average and an efficient device can reach up to 60-80 EUR.
Example 3 - swimming pool hall or covered pool
Swimming pools represent the most demanding scenario, as humidity is constantly high and the dehumidifier runs almost continuously for most of the day. With a high-performance model such as SECCOULTRA 38l/24h, with a power consumption of around 480-550 W and an average running time of 14-16 hours per day, the daily consumption is 7-8.8 kWh. At a price of 0.20 EUR/kWh, the costs amount to 1.4-1.76 EUR per day, approximately 42-53 EUR per month, and around 500-640 EUR per year with year-round operation at a swimming pool. For swimming pools, it is even more important to correctly dimension the capacity according to the surface area - an undersized device runs continuously and, despite this, cannot manage the humidity, which increases costs without the corresponding effect. The topic of dimensioning is covered in the article "What dehumidifier capacity do I need according to room size," and the differences in usage are discussed in the article "Dehumidifier for an apartment, cellar, or swimming pool - what is the difference."
Example 4 - drying a building or flooded area
During intensive drying of a new building after wet processes (floor screed, plastering) or after flooding, the dehumidifier is practically running non-stop, 20-24 hours per day, during a short but intensive period of 2-4 weeks. With a model SECCOULTRA 38l/24h with a power consumption of 500 W and a running time of 20 hours per day, the daily consumption is 10 kWh, which at 0.20 EUR/kWh amounts to 2 EUR per day. For three weeks of intensive drying (21 days), this is approximately 42 EUR - an amount that is negligible compared to the value of the saved time and the risk represented by moisture trapped in the building structure (mold, floor damage, delays in further work).
Comparison of operating costs of condensation and adsorption dehumidifiers
The following table summarizes an approximate comparison of both principles in terms of operating costs under different temperature conditions. The values are average and serve to illustrate the differences, not as precise data for a specific model.
| Parameter | Condensation dehumidifier | Adsorption dehumidifier |
|---|---|---|
| Dehumidification factor at 20 °C | 2-4 l/kWh | 0.5-1.2 l/kWh |
| Dehumidification factor at 5-10 °C | 0.5-1 l/kWh (performance decreases) | 0.8-1.3 l/kWh (stable) |
| Typical power consumption for a household | 150-400 W | 250-650 W |
| Recommended use | apartment, cellar above 10 °C, swimming pool | cold cellar, garage, cabin without heating |
| Effect of low temperature on costs | increase significantly, performance decreases | remain relatively stable |
Impact of temperature, humidity, and room size on actual consumption
The power consumption stated on the energy label assumes so-called reference measurement conditions (usually 20-27 °C and 60-80 % relative humidity). In real operation, the conditions change and so does the consumption. The higher the input air humidity, the more water needs to be condensed and the longer the compressor runs at full power - this means higher consumption, but also a faster effect. Conversely, at low humidity, the compressor cycles for shorter periods and consumption decreases, even though the device is connected to the grid for the same amount of time.
Air temperature has a significant impact on condensation dehumidifiers. When the temperature drops below 15 °C, the efficiency of the cooling circuit decreases, the evaporator may be covered with frost (which triggers defrosting cycles, during which air is not dehumidified, but energy is consumed), and the dehumidification factor decreases by up to half compared to room temperature. This is why in cold cellars or non-insulated garages, a condensation dehumidifier may still work, but its operating costs increase and the actual dehumidification performance is lower than stated in the catalog (which is usually given at 30 °C and 80 % humidity according to the standard, or at milder 20-27 °C).
The size and characteristics of the room affect consumption indirectly - a larger air volume and higher humidity production (clothes drying, showering, swimming pool, damp walls) means a longer time needed to reach the target humidity, thus a longer compressor running time and higher consumption. This is precisely why correct capacity sizing in relation to the size and load of the room is key - an undersized device runs almost continuously and still cannot keep up, which increases costs without an adequate result, while an overly oversized device has lower operating hours but a higher purchase price. Optimal sizing is discussed in detail in the article "What dehumidifier capacity do I need according to room size."
Estimated consumption of specific models in the range
In practice, customers often ask us for specific figures for the models we offer. The following overview is indicative and is based on typical values for the respective performance segment - for precise parameters, we always recommend checking the technical specifications of the specific product.
- SECCO 11l/24h - entry-level home model, power consumption approx. 150-180 W, suitable for smaller apartments and rooms. At normal usage (5-6 hours of compressor operation per day), the costs amount to roughly 5-7 EUR per month during the seasonal operation.
- SECCOREALE EL 11l/24h - similar performance segment as the previous model, power consumption approx. 160-190 W, electronic control allows for more precise setting of target humidity and thus more efficient compressor cycling.
- SECCOASCIUTTO EL 12l/24h - compact model with slightly higher dehumidification capacity at similar power consumption (approx. 170-200 W), suitable for apartments, cottages or small cellars.
- SECCOPROF 28l/24h - mid-range performance for larger spaces, cellars, workshops or small businesses, power consumption approx. 350-400 W. At year-round operation in a cellar, annual costs amount to roughly 200-290 EUR depending on the intensity of operation.
- SECCOULTRA 38l/24h - the most powerful model in the range, power consumption approx. 480-550 W, intended for swimming pool halls, larger warehouses, building drying or spaces with permanently high humidity. At intensive operation at a swimming pool, annual costs amount to roughly 500-650 EUR, while at short-term intensive building drying, the costs are only tens of euros for the entire operation.
Note that when comparing models, it is not sufficient to look only at the stated power consumption - equally important is the ratio of power consumption to actual dehumidification capacity (litres per 24 hours), i.e. the mentioned dehumidification factor. A model with slightly higher power consumption that, however, dehumidifies significantly more air in the same time, may be cheaper to operate in the end, because it needs to run for a shorter period of time.
How to reduce the operating costs of a dehumidifier
There are several proven practical measures that can reduce energy consumption without reducing comfort or the efficiency of dehumidification.
- Set a realistic target humidity - most models allow you to set the hygrostat to the desired relative humidity (usually 40-60 % for living). Setting the target value too low (e.g. 30 %) forces the compressor to run much longer, while it is not necessary for healthy living or furniture protection.
- Close the doors and windows of the room where the dehumidifier is operating - a constant inflow of moist air from outside prolongs the time needed to reach the target humidity and increases consumption.
- Place the device correctly - free space around the air intake and exhaust, away from direct sunlight and corners with limited air circulation, improves the efficiency of air exchange and shortens the required operation time. A detailed guide can be found in the article Installation and placement of a dehumidifier in a room.
- Clean the filter and heat exchanger regularly - a dirty filter or dusty evaporator reduce air flow, prolong the time needed for dehumidification and increase consumption by even tens of percent. The recommended cleaning procedure can be found in the article Maintenance and cleaning of a dehumidifier.
- Address the cause of moisture, not just the effect - if the source of moisture is poor waterproofing, insufficient ventilation or a thermal bridge, the dehumidifier will have to work continuously at full capacity and the operating costs will be disproportionately high. In such a case, it is more effective to address the cause (renovation, ventilation) and use the dehumidifier only as a supplementary or temporary solution.
- Choose the right type of condensate drainage according to the mode of use - for continuous operation, a direct drain via a hose into the waste is more suitable than emptying the tank, because a forgotten full tank will switch off the device and interrupt the process, thus prolonging the total time needed to reach the desired humidity. More information can be found in the article Condensate drainage - hose vs. tank.
Seasonal and year-round operation - when is it worth investing in a more powerful model
When deciding between a cheaper model with lower performance and a more expensive, but more powerful and efficient device, it is useful to calculate the total costs over the entire lifetime (purchase price plus operating costs for the expected period of use), not just the initial investment.
For seasonal use in an apartment (autumn-spring, approx. 4-5 months per year), the differences in operating costs between models are in the range of single to low double-digit euros per year, so the decisive criterion should be the appropriate performance for the given room and the reliability of the device.
For year-round operation in a cellar, garage or at a swimming pool, the differences in efficiency become much more pronounced - here, the difference between an average and an efficient model can amount to 50-150 EUR per year, which quickly balances out the difference in purchase price over several years of operation. In such cases, we recommend choosing a more powerful model (e.g. rather than borderline dimensioning, choose a step higher performance device from the SECCOPROF or SECCOULTRA range), because the device will operate at a lower percentage of compressor utilization, which reduces wear and costs per kilogram of dehumidified air.
For short-term, but intensive use (building drying, renovation after flooding), it is, on the contrary, worth renting or buying a powerful model that can complete the task in a shorter time - higher immediate power consumption is compensated by significantly shorter operation time, so total energy costs can be lower than when using an underdimensioned device that would require several times longer to achieve the same result.
Common questions about the operating costs of a dehumidifier
How much electricity does a dehumidifier consume per month during normal use in an apartment?
For a small home model with a power consumption of around 150-200 W and an average compressor operation of 5-7 hours per day, the monthly consumption ranges roughly between 25-45 kWh, which at a price of 0.20 EUR/kWh amounts to approximately 5-9 EUR per month. The exact value depends on the target humidity, room size and the source of moisture.
Is it cheaper to let the dehumidifier run continuously or to turn it on only occasionally?
We recommend leaving the device on in automatic mode with the hygrostat set to the desired humidity, rather than manually turning it off and on. The compressor itself controls the operation according to the current humidity and works most efficiently in this way. Frequent manual switching on and off also puts more strain on the compressor than smooth cycling controlled by the electronics.
Why does my dehumidifier consume more energy in winter than in summer?
In condensation dehumidifiers, the efficiency of the cooling circuit decreases with lower air temperatures and the device needs more time (and thus also energy) to remove the same amount of water. At temperatures below 15 °C, defrosting cycles of the evaporator may also be triggered, during which air is not dehumidified, but energy is still consumed. In cold spaces, therefore, a desiccant type or a condensation model with a quality automatic defrosting is more suitable.
Is it worth buying a more powerful model even if I need fewer liters per day?
Yes, for year-round or intensive use - a more powerful model reaches the target humidity faster and then runs for a shorter time, thus reducing wear and total energy consumption. For occasional seasonal use in an apartment, the difference in costs is not significant enough, so there a model dimensioned exactly for the room size is sufficient.
Does the placement of the dehumidifier affect its consumption?
Yes, significantly. A device placed in a corner of the room, behind furniture or close to the wall has limited air circulation, which prolongs the time needed to reach the target humidity and increases consumption. We recommend at least 20-30 cm of free space around the air intake and exhaust and placing the device as close as possible to the source of moisture (e.g. near drying laundry or a damp wall).
How can I determine the actual consumption of my dehumidifier at home?
The most reliable method is to use a power meter connected between the socket and the device's power cable (commonly available socket meters with a display). The meter will record the actual consumption including all compressor cycles during a given period and will provide a more accurate reading than a theoretical calculation based on the rated power.
Summary
Operating costs of a dehumidifier depend on a combination of the rated power, the actual running time of the compressor, the temperature and humidity in the room, and the type of the device. Condensation models are clearly more cost-effective at normal room temperatures, while absorption models are suitable for colder spaces. For regular seasonal use in a home, we are talking about single-digit euros per month. For year-round operation in a pool area or basement, the costs can reach hundreds of euros annually, so it is worth investing in a more powerful and efficient model in such cases. When choosing a specific device, we recommend considering the dehumidification capacity (l/24h), the dehumidification factor (l/kWh), and the actual conditions of the space where the device will operate - if you have any doubts, we are happy to help you choose the right model from our range of dehumidifiers specifically according to your particular space and usage.
Do you have a question about this topic?
Having trouble deciding or dealing with a specific situation in your home? Write to us - we are happy to advise you.