How Much Does a Dehumidifier Cost to Run in the UK?

A modern compressor dehumidifier typically costs around 3p–11p per hour to run in the UK, depending on its power consumption. An efficient 10–12L model may cost around 3.5p–5p per hour, while a larger 20–25L machine might cost roughly 5p–11p per hour. Desiccant dehumidifiers usually use more electricity and can cost around 8p–16p per hour.

Those figures assume an electricity price of 26.32p per kWh, which is Ofgem’s average electricity unit rate for Direct Debit customers on standard variable tariffs in Great Britain between 1 October and 31 December 2026. Your actual tariff may be different.

The good news is that a properly used dehumidifier doesn’t necessarily consume its full rated power continuously.

Once your chosen humidity level has been reached, a machine with a good humidistat can switch off its compressor and only restart when humidity rises again.

So although it’s useful to calculate the theoretical hourly cost, your actual monthly electricity bill will depend on how long the dehumidifier is actively removing moisture.

In this guide we’ll calculate exactly how much different dehumidifiers cost to run, explain how to work out the cost of your own machine, and look at whether leaving a dehumidifier switched on all day is as expensive as it sounds.

Quick answer: how much does a dehumidifier cost per hour?

The easiest way to estimate running cost is by looking at the machine’s wattage.

Using an electricity price of 26.32p/kWh, the theoretical cost while the appliance is drawing the stated amount of power is approximately:

This means a fairly efficient 200W compressor dehumidifier costs just over 5p per hour while actively consuming 200W.

Run it at that power for eight hours and the theoretical electricity cost would be around 42p.

Use it at that power for eight hours every day for 30 days and that would be approximately £12.63 per month.

However, this calculation assumes the machine draws 200W for every minute of those eight hours.

In normal humidity-control use, that often won’t happen.

What electricity price are we using?

For the calculations in this article we’re using 26.32p per kilowatt hour.

That is Ofgem’s average electricity unit rate for a Direct Debit customer on a standard variable tariff under the energy price cap from 1 October to 31 December 2026.

There are a few important caveats.

Your actual electricity rate can vary according to:

• where you live

• your electricity supplier

• whether you’re on a fixed or variable tariff

• how you pay

• whether you have a time-of-use tariff

• your meter and tariff type

The Ofgem figure is an average across England, Scotland and Wales.

Northern Ireland has a separate energy market and regulatory system, so households there should use the unit rate shown on their own electricity tariff instead.

We also don’t include the electricity standing charge when calculating the cost of running a dehumidifier.

That’s because you pay your standing charge regardless of whether the dehumidifier is switched on.

How to calculate the running cost of your own dehumidifier

You only need two numbers:

1. The wattage of your dehumidifier

2. Your electricity unit rate

The formula is:

Watts ÷ 1,000 × electricity price per kWh = cost per hour

For example, imagine your dehumidifier uses 200W.

First convert watts into kilowatts:

200 ÷ 1,000 = 0.2kW

Then multiply that by the electricity price:

0.2 × 26.32p = 5.264p

So the dehumidifier costs approximately:

5.3p per hour

If it actively runs for eight hours:

5.264p × 8 = 42.1p

And if that happened every day for 30 days:

42.1p × 30 = £12.63

You can substitute the wattage and electricity rate with the figures for your own machine and tariff.

How much do 10L, 12L, 20L and 25L dehumidifiers cost to run?

The litre rating alone does not tell you how much electricity a dehumidifier uses.

Two different 20L machines can have considerably different power requirements.

However, we can use one current product family to demonstrate how running costs generally increase with capacity.

At 20°C and 60% relative humidity, Meaco lists the following consumption figures for its current Arete Two compressor range:

• 10L: 136W

• 12L: 136W

• 20L: 207W

• 25L: 250W

Using our 26.32p/kWh electricity rate gives us:

These are examples from one particular range rather than universal figures for every dehumidifier of that capacity.

That’s important.

A different 12L compressor machine currently sold in the UK, for example, is listed at around 190–200W, while a current Pro Breeze 20L model is listed at considerably higher consumption than the 207W example above.

So when comparing dehumidifiers:

Check the watts, not just the litres.

Does a dehumidifier really cost that much all day?

Not necessarily.

This is where many running-cost calculations become misleading.

Imagine you have a 20L machine drawing 207W.

If you simply calculate:

207W × 24 hours × 30 days

you get an electricity cost of roughly:

£39.23 per month

That sounds quite expensive.

But that calculation assumes the compressor is running continuously at 207W, 24 hours a day, every day of the month.

A good automatic dehumidifier doesn’t normally need to do that once the home is under control.

For example, Meaco’s humidity control system stops active dehumidification when the target humidity is achieved, periodically checks the air, and restarts when humidity has risen sufficiently.

Other brands use similar humidistat-based systems.

So there is an important difference between:

Leaving a dehumidifier switched on for 24 hours

and:

Having the compressor actively running for 24 hours.

They aren’t necessarily the same thing.

How much does it cost to leave a dehumidifier on 24/7?

If your dehumidifier has an automatic humidistat, leaving it available to operate 24 hours a day doesn’t necessarily mean it continuously consumes its maximum rated wattage.

Once humidity reaches the chosen level, many machines stop dehumidifying and periodically monitor the room instead.

This means the actual cost depends on how often the compressor has to restart.

When you first install a dehumidifier in a damp property, it may run almost continuously.

That’s because it isn’t just removing moisture from the air.

Moisture stored within:

• plaster

• walls

• furniture

• fabrics

• carpets

• timber

can gradually be released back into the room.

Once the home reaches a more stable humidity level, the machine may need to run far less frequently.

This explains why the first few days or weeks of dehumidifier use can consume noticeably more electricity than maintaining the same home afterwards.

The theoretical cost of running continuously

It can still be useful to calculate the absolute maximum-style scenario.

At 26.32p/kWh:

Again, this is what you’d pay if the appliance actually drew that amount of power continuously for every hour of the month.

It shouldn’t automatically be treated as your expected electricity bill.

Why does my dehumidifier’s power consumption change?

Another detail that isn’t always obvious is that a compressor dehumidifier’s electricity consumption isn’t necessarily fixed.

Temperature and relative humidity can affect both power consumption and water extraction.

For example, Meaco publishes the following data for its current 20L Arete Two:

So the same machine can use different amounts of electricity depending on the conditions in which it’s operating.

This also shows why simply comparing watts isn’t enough when choosing a machine.

A dehumidifier that consumes slightly more power but removes considerably more water can potentially be more efficient per litre of moisture removed.

Which? takes this approach in its own testing, measuring energy consumption alongside the amount of water extracted rather than looking at wattage in isolation.

Is a bigger dehumidifier more expensive to run?

Usually while operating, yes — but not necessarily overall.

A 25L dehumidifier will commonly draw more power than a 10L machine.

However, that doesn’t automatically mean the smaller machine will cost less to achieve the same result.

Imagine a small dehumidifier has to run almost continuously because it is struggling to control humidity across an entire family home.

A larger and more efficient machine might remove the required moisture much faster, reach the target humidity and then spend longer switched off.

This is why buying the smallest available model purely because it has the lowest wattage isn’t always economical.

The important measure is closer to:

How much electricity does it take to achieve the humidity level I want?

rather than:

Which machine uses the fewest watts while switched on?

Correct sizing matters.

Compressor vs desiccant: which costs more to run?

There are two main kinds of household dehumidifier:

• compressor/refrigerant

• desiccant

For a normally heated British home, compressor dehumidifiers are generally more economical to run.

Which? says refrigerant machines are typically more energy efficient at normal room temperatures, while desiccant models become more appropriate in cold, unheated spaces.

The difference in wattage can be substantial.

For example, the EcoAir DD1 Classic desiccant dehumidifier is currently rated at:

• 300W in low mode

• 580W in high mode

At 26.32p/kWh that works out at approximately:

300W: 7.9p/hour

580W: 15.3p/hour

Compare that with our earlier compressor examples:

136W: 3.6p/hour

207W: 5.4p/hour

250W: 6.6p/hour

So why would anyone buy a desiccant model?

Because compressor dehumidifiers become progressively less effective as temperatures fall.

In an unheated:

• garage

• workshop

• cellar

• caravan

• boat

• conservatory

a desiccant dehumidifier may remove considerably more moisture despite consuming more electricity per hour.

At very low temperatures, the cost per litre of water removed can therefore be more important than the cost per hour.

For normal heated rooms, though, we’d generally favour an efficient compressor model if running cost is a priority.

How much does a dehumidifier cost when drying clothes?

Laundry is one of the best uses for a dehumidifier, but it also tends to keep the machine working harder than everyday humidity maintenance.

Many laundry modes run the fan at high speed and lower the target humidity so that moisture continues to be removed from wet clothes.

As a rough example, suppose your laundry session lasts six hours.

Using the consumption figures from our earlier compressor examples:

Actual consumption can be lower if the compressor switches off during the session.

Which?’s testing provides another useful benchmark. Its current laundry comparison says that the Best Buy dehumidifiers it has tested average around 6p per hour, with tested running costs ranging from approximately 2p to 13p per hour. It also reports that desiccant machines generally cost more to operate than refrigerant models.

Is a dehumidifier cheaper than a tumble dryer?

This isn’t quite as simple as comparing the cost per hour.

A dehumidifier can cost considerably less per hour, but it will normally take longer to dry clothes.

A tumble dryer directly heats and tumbles the load, whereas a dehumidifier gradually removes moisture from the room while the clothes remain on an airer.

The economics also vary enormously depending on the type of tumble dryer.

Modern heat-pump dryers consume much less electricity than older vented or condenser machines.

Which?’s 2026 comparison found that tumble dryers remain the fastest option for substantial laundry loads, and efficient heat-pump models can be surprisingly economical when drying several large loads each week. Dehumidifiers become particularly attractive when you also need them to control condensation or damp in the room.

So we’d view a dehumidifier primarily as:

A humidity-control appliance that can also be extremely useful for drying washing.

If you’re already fighting condensation every winter, that makes the running cost easier to justify because the machine is performing two jobs simultaneously.

What affects the running cost of a dehumidifier?

Several factors determine what you actually pay.

1. Wattage

This is the simplest one.

All else being equal, a 150W machine costs less per hour than a 400W machine.

But don’t consider wattage without also looking at water extraction and suitability for the room.

2. How humid your home is

A room at 75% relative humidity gives the machine plenty of work to do.

A room sitting close to its 55% target may require the compressor to operate only occasionally.

The wetter the home, the longer you can expect the machine to run initially.

3. Your target humidity

Setting a machine to 40% RH will usually require considerably more work than maintaining 55–60%.

For most normal household humidity control, trying to make the home unnecessarily dry simply wastes electricity.

A sensible target around 50–60% RH is appropriate for many homes.

4. Room temperature

Temperature significantly affects compressor-dehumidifier performance.

In a normal heated home, a compressor unit is usually efficient.

In a very cold room, it can extract considerably less water.

That may mean paying for hours of electricity without removing as much moisture as expected.

In sufficiently cold conditions, a desiccant model can therefore make more sense despite its higher wattage.

5. Whether you’re drying laundry

A wet load of washing introduces a large amount of moisture to the room.

The dehumidifier will therefore remain active for longer.

Laundry mode also commonly uses a higher fan speed and a lower humidity target.

6. The size of your dehumidifier

An undersized machine may be inexpensive per hour but need to operate far longer.

A correctly sized machine has a better chance of reaching the target humidity and switching into standby.

7. Airflow

Restricting the air entering or leaving the machine can reduce performance.

Keep the filter clean and follow the manufacturer’s clearance instructions.

If the appliance has to process air through a badly clogged filter, you’re unlikely to get the best moisture removal for the electricity being consumed.

How can I make my dehumidifier cheaper to run?

There are several simple ways.

Use the humidistat rather than a timer

If your machine has a good automatic humidity setting, use it.

Rather than guessing that you need four, eight or twelve hours every day, tell the machine what humidity you’re trying to maintain.

Once it reaches the target, it can regulate itself.

Don’t set the humidity unnecessarily low

Trying to maintain 35–40% RH throughout a normal home uses extra electricity without providing much benefit.

For general humidity control, roughly 50–60% RH is a much more sensible goal.

Laundry mode is different because temporarily lowering humidity can help clothes dry more quickly.

Buy the right size

Don’t automatically choose the smallest machine.

A correctly sized 20L model that quickly reaches its target can potentially make more sense than a 10L appliance operating near continuously.

Our separate What Size Dehumidifier Do I Need? guide explains this in more detail.

Use the right technology

For most heated houses:

Compressor dehumidifier

For genuinely cold areas:

Consider desiccant

Choosing the wrong technology for the temperature can result in poor water extraction and wasted electricity.

Close exterior windows while actively dehumidifying

Running a dehumidifier beside an open window can mean continually introducing more outside air for the appliance to process.

During active dehumidification or laundry drying, closing exterior windows allows the appliance to deal with the air inside the room.

This doesn’t mean permanently blocking your home’s intended ventilation. Extractor fans, trickle vents and appropriate ventilation still have an important role in controlling indoor moisture and air quality.

Dry laundry in one room

If you’re using a dehumidifier for washing, place the clothes airer and dehumidifier in a suitable room and close the internal door.

That reduces the volume of air the machine needs to process.

Allow space between garments so air can circulate around them.

Use a high spin speed first

The more water your washing machine removes mechanically, the less the dehumidifier has to remove afterwards.

If the fabric allows it, using an appropriate higher spin speed can therefore shorten drying time without asking the dehumidifier to do all the work.

Clean the filter

Airflow is fundamental to dehumidification.

Check the manufacturer’s instructions and regularly clean the washable air filter where fitted.

Take advantage of cheaper electricity periods

If you have a time-of-use electricity tariff, laundry drying can sometimes be shifted into a cheaper period.

The potential saving will depend entirely on your tariff.

Don’t assume overnight electricity is cheaper unless your plan actually offers reduced off-peak rates.

Should I turn my dehumidifier off when I go to work?

Not necessarily.

If the machine is designed for unattended automatic operation and you’re using it in accordance with the manufacturer’s instructions, the most efficient strategy may be to let its humidistat decide when dehumidification is needed.

Turning it off manually for long periods allows humidity to rise again.

When you switch it back on, the machine may then need to work hard to bring the property back to your target.

That said, there’s little benefit in manually forcing continuous operation once humidity is already under control.

The key is:

Automatic humidity control rather than continuous maximum operation.

Why does my dehumidifier cost more when I first buy it?

This is normal in a damp home.

Initially, the machine may run for long periods because there is moisture stored throughout the property.

As the humidity in the air falls, moisture from furnishings and building materials can gradually migrate back into the air.

The machine removes that water too.

After the home has dried to a more stable level, its workload should generally decrease provided large amounts of new moisture aren’t continually being introduced.

So don’t necessarily judge the long-term running cost based on your first week of ownership.

Is an energy-efficient dehumidifier worth paying more for?

Potentially, especially if you use it regularly.

Imagine two suitable dehumidifiers:

Machine A: 200W
Machine B: 400W

At 26.32p/kWh:

Machine A costs approximately 5.3p/hour.

Machine B costs approximately 10.5p/hour.

If both achieved the same result in the same amount of time and ran for eight hours a day over a 120-day damp winter period:

Machine A would cost around £50.53.

Machine B would cost around £101.07.

That’s roughly £50 difference in one season.

But there is an important qualification:

You need to know whether the two machines genuinely deliver comparable dehumidification performance.

The best comparison isn’t just:

watts vs watts

but:

energy consumption vs useful water extraction.

That’s why we’d look at extraction performance, room temperature, wattage and humidistat behaviour together when reviewing dehumidifiers.

What should I look for if low running costs are important?

When shopping for a dehumidifier, check:

• Power consumption in watts

• Extraction performance at realistic conditions

• Automatic humidistat

• Compressor or desiccant technology

• Room-temperature suitability

• Airflow

• Laundry mode

• Automatic standby behaviour

• Independent energy-efficiency testing where available

Don’t be overly impressed by a low wattage figure on its own.

A 100W machine that hardly extracts any water isn’t necessarily more economical than a 200W machine doing twice the useful work.