How much does a dehumidifier cost to run in Ireland?
Quick answer: A mains dehumidifier costs between €0.04 and €0.13 an hour to run at Ireland’s domestic day rate of about €0.38/kWh, based on the rated power of the 11 models we track that publish one. We also track one sub-100 W mini unit, which costs less again but only pulls out a fraction of a litre a day. A typical 185 W unit run overnight for 8 hours costs €0.56 on the day rate and €0.27 on a night rate — roughly €16.87 a month if you run it every night. Those are ceilings: the humidistat cuts the compressor once the room dries out.
Dehumidifiers have a reputation in Ireland for being expensive to leave on. This page works out whether that is true, using the wattage each manufacturer publishes and the price of a unit of electricity here — with every step of the arithmetic shown, so you can redo it with the rate on your own bill.
The three numbers that decide your bill
There is no fourth. A dehumidifier's running cost is its rated power in kilowatts, multiplied by the hours you run it, multiplied by your unit rate in euro per kWh.
- Rated power. The wattage on the plate. Of the 17 dehumidifiers in our guides, 12 publish one; the rest do not, and we leave those blank rather than estimate them.
- Unit rate. We use €0.38/kWh for the day rate and €0.18/kWh for a typical smart-meter night rate, cross-checked against SEAI energy price statistics and published supplier standard rates, July 2026. Yours is on your bill.
- Hours. Ours is 8 hours a day — an assumption, not a measurement. Scale everything below to how you actually run yours.
So a 185 W machine is 0.185 kW, and 0.185 × 0.38 = €0.07 an hour. That is the whole calculation.
What a night, and a month, actually cost
Three machines from our guides — the lowest draw we have a figure for, a typical mid-range unit, and the highest — run through the same sum.
| Model | Rated power | One hour, day rate | 8 hours overnight, night rate | A month at 8 h/day, day rate |
|---|---|---|---|---|
| Belaco 1000ml Portable Dehumidifier | 36 W | €0.01 | €0.05 | €3.28 |
| Masterplug 3-in-1 Smart Dehumidifier 12L | 185 W | €0.07 | €0.27 | €16.87 |
| Meaco DD8L Junior Desiccant Dehumidifier | 330 W | €0.13 | €0.48 | €30.10 |
Tariff source: €0.38/kWh day rate and €0.18/kWh night rate, cross-checked against SEAI energy price statistics and published supplier standard rates, July 2026. Rated power is each manufacturer's own published figure. The full table, for every model we track, is on What a dehumidifier actually costs to run in Ireland.
When you run it is worth as much as which one you buy
This is the part most buying guides skip. 7 of the dehumidifiers in our guides are rated at exactly the same 12 L a day, so comparing those is fair — they are being asked to do the same job. Their draw runs from 136 W (MeacoDry Arete Two 12L Dehumidifier & Air Purifier) to 210 W (HOMCOM 12L/Day Dehumidifier (Continuous Drainage)), which over a month at 8 hours a day is €12.40 against €19.15.
- Buying the most frugal of those instead of the thirstiest saves €6.75 a month.
- Taking any one of them and moving the run onto a night rate saves €8.88 a month — worked on the 185 W machine in the table above.
In other words, the tariff you run it on is worth about as much as the best model choice available to you, and switching to it costs nothing at all if your machine or your socket has a timer. Neither number is large — which is the honest headline of this page.
Cost per litre: the number that reorders the list
Cost per hour rewards the smallest machine, which is not the same thing as the cheapest machine. A unit that sips electricity but pulls very little water out of the air can cost more per litre removed than a bigger one that does the job and switches off. On the 11 models where the manufacturer publishes both a wattage and a rated extraction, running flat out for 24 hours works out at €0.10 per litre for the MeacoDry Arete Two 12L Dehumidifier & Air Purifier and €1.09 per litre for the Belaco 1000ml Portable Dehumidifier — a 10.6× spread that the per-hour column does not show you.
The catch, said plainly. Rated extraction is measured at around 30 °C and 80% relative humidity. An Irish bedroom in November is nowhere near that, so every machine here will remove less than its rating and your real cost per litre will be higher than the figures above. We use the rated number because it is the one the manufacturer publishes and you can check it — not because we think you will get it.
Put next to a heater, it is not a big number
The most common rating among the 26 electric heaters we track is 2000 W, and a heater converts essentially all of that into heat the whole time it is on. That heater costs €0.76 an hour at the day rate. The 185 W dehumidifier above costs €0.56 for a full 8-hour run — so a whole night of dehumidifying costs about the same as 44 minutes of that heater. That is the comparison worth holding on to: on an Irish electricity bill a dehumidifier is a small, steady cost, and the heating is where the money goes. See what every heater we track costs per hour if you want the other half of that sum.
What these figures are not
They are not your bill. Every number here is rated draw at full power, multiplied out. A compressor dehumidifier with a humidistat switches the compressor off once the room hits the target humidity, so it spends a good part of every hour drawing almost nothing. Desiccant models are the exception worth knowing about: they heat a rotor rather than run a compressor, so they sit much closer to their rated draw the whole time they are on — the Meaco DD8L in the table above is one of these, and its figure is nearer to a real hourly cost than the others.
They do not include your standing charge or VAT changes. The unit rate is the marginal cost of switching the thing on. The standing charge is there either way.
They are not a measurement. We have not put a plug-in energy monitor on these machines. Everything above is published wattage and arithmetic, which is exactly why we show the arithmetic — so you can check it rather than trust it. Spot a wattage we have wrong? Tell us and we will correct it.
Frequently asked questions
Is it cheaper to run a dehumidifier at night?
Yes, if you are on a smart-meter tariff with a night rate. The same 8-hour run on the 185 W model above costs €0.56 at the day rate and €0.27 at a night rate of €0.18/kWh. On a flat tariff the time of day changes nothing.
Does leaving a dehumidifier on all day cost a lot?
Twenty-four hours at full power on the 185 W model is €1.69 at the day rate. That is the ceiling, not the bill: a compressor model with a humidistat shuts the compressor off once the room reaches its target humidity, so it spends much of the day drawing almost nothing.
Is a dehumidifier cheaper than heating the room?
On these figures, comfortably. The dehumidifier costs €0.07 an hour at full draw; a typical 2 kW electric heater costs €0.76. They do different jobs, so this is not an either/or — but drying the air is the cheap part of the problem.
Is a dehumidifier cheaper than a tumble dryer?
We do not publish a figure for this, because we do not track tumble dryers and we will not put a number on the page that we have not verified. The sum is the same one used here, and you can do it: take the rated watts off the plate on the back of your dryer, divide by 1,000, multiply by your unit rate, and multiply by the length of a cycle.
Which dehumidifier is cheapest to run?
Of the 11 mains models where the manufacturer publishes a wattage, the lowest draw is the MeacoDry Arete One 6L Dehumidifier & Air Purifier at 101 W (€0.04 an hour) and the highest is the Meaco DD8L Junior Desiccant Dehumidifier at 330 W (€0.13 an hour). Cheapest per hour is not the same as cheapest per litre of water removed, which is the comparison that matters if the two machines are not rated to pull out the same amount.
PickIreland is reader-supported. When you buy through links on our site, we may earn an affiliate commission at no extra cost to you. Running costs on this page are calculated from manufacturer-published rated power and are indicative, not measured.