How Expensive Are Dehumidifiers To Run?
I often get asked about the running costs and energy efficiency of dehumidifiers, after all, the cost of electricity is rising much faster than inflation. Even with the economy picking up I think that in the coming years and decades people are still going to look to save wherever they can, so it makes sense to do your homework before buying an electrical item, whether it be a television, microwave oven or a dehumidifier.
Quick Summary
Analysing the running costs of a dehumidifier is surprisingly difficult, due to the positive effects of the machine on your home’s climate. Let’s take a look at the different aspects:
On the negative side are the obvious points:
- According to Electrician Las Vegas, cost of the electricity to run the machine: 48p to £1.56 per week depending on the size of the dehumidifier and the conditions found in your home (e.g. insulation)
On the positive side, a little less obvious:
- Your home feels warmer and so the thermostat can be turned down by at least 1°C, saving more than £65 per year
- Your home requires less energy to heat the air, as moist air takes more energy to heat
- Your home can cope with less ventilation and thereby conserves more heat
- There’s less damage to walls and furnishings that would have been damaged by the excess moisture in the air
- There’s no more need to buy anti-mould sprays, moisture capture devices and other little items that add up over the long run
If you’re convinced, take a look at our dehumidifier reviews to make sure you choose your machine wisely.
If you’re not sure, let’s now dive into the costs of owning a dehumidifier a little deeper.
Dehumidifier Energy Costs
The initial costs of buying a dehumidifier are obvious, you can get a great machine for just under £120 (check out the current sale savings here). So I think it’s best to concentrate on the electricity costs.
First of all, the cost of electricity currently is roughly 15 pence per kWh. Then, once a dehumidifier has become established and there’s a steady level of humidity in your home you can expect it to switch itself on for two to four hours per day to maintain your desired level of humidity. The actual length of time it’s switched on for will depend on how you’ve set the humidity level on the machine, the ventilation, the size of your home and the humidity sources in your home. The high level of humidity can be caused by poor ventilation. In this case, air duct cleaning is necessary. There are many contractors offering such services, so all you need to do to find one is to enter online search request “air duct cleaners near me“.
Then let’s compare a couple of different dehumidifiers wattages:
- EcoAir DC12 = 230 watts (on maximum power, not economy mode)
- EcoAir DC202 = 370 watts (on full power, not economy mode)
Towards the low end of costs, a EcoAir DC12 on for 2 hours per day would cost something like the following:
- 230 watts = 0.23kW, and 0.23kW x 2 hours per day = 0.46kWh per day.
- 0.46kWh per day x 15 pence per kWh = 6.9 pence per day, or £25.19 per year.
At the upper end, the more powerful EcoAir DC202 on maximum for 4 hours per day would cost 22.2 pence per day, or £81.03 per year.
Can A Dehumidifier Save You Money?
The short answer is yes, but how?
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- Your home feels warmer – but how is this possible? This is due to the reduced moisture (humidity) in the air. Moisture in the air on cool days has a couple of effects, both of which make us feel cooler. Firstly and most simply, the moisture on our skin and clothes from the air takes in heat energy from our bodies and results in evaporative cooling. This is has the same cooling effect that sweating does on hot days or during exercise.The second and much larger effect is that the insulating layers of air trapped between our skin and clothes, which is how our clothes keep us warm is more difficult to heat as water takes four times the energy to heat than air.As your home ‘feels’ warmer, your thermostat can be adjusted down by a degree or two. The Energy Saving Trust believes you can save around £65 per year just by turning your thermostat down by a single degree!
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- Your home requires less energy to heat. As mentioned in the previous point, the specific heat capacity of water is over four times greater than air, which means water takes over four times the energy to heat than air. At 20 degrees Celsius a cubic metre of air can ‘hold’ 18g of water, where the relative humidity would be recorded at 100%. At 45% humidity (ideal for humans) a cubic metre of air will ‘hold’ 8g of water.A 4-bed house could contain roughly 1000 cubic metres of air. In a UK house the humidity is unlikely to ever hit 100%, so for this calculation we’ll assume 75%. This house would hold an extra 5.4kg of water in the air at 75% rather than the 45% ideal. It takes 0.0063kWh to heat this 5.4kg of water by 1 degree Celcius (trust us). If your heating came on twice per day and needed to heat your home by 2 degrees Celcius each time then this would equate to just over 9kWh per year, which at 15 pence per kWh is about £1.40 per year… So this point isn’t very important in the overall running costs equation.
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- Everyone knows that poor ventilation can cause mould, damp, condensation and all the nasties that you buy a dehumidifier to fix and prevent coming back again. If you have mould in your home, it can be tricky removing it in the correct way, find a mould removal specialist near you today. Often the way that we combat these effects it to leave the bathroom window open after a shower, leave other windows open to flush out the stale air and leave the ventilation flaps on the windows open, even during winter.The great thing about owning a dehumidifier long term is that once the initial drying out period is finished, when the machine has extracted all of the excess water from your home, ventilation won’t be as important, as essentially the dehumidifier is doing that for you. This means you can close off those energy-wasting drafts, which will make your home much more energy efficient, warmer and keep your heating bills lower. The US government believes blocking off drafts can result in savings from 5% to 30% per year. The average UK heating bill is now over £600 per year, so saving 5% by being able to reduce ventilation through owning a dehumidifier could save the average person £30 per year.
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- Damage to walls through excess water, peeling paint and mould growth, damage to windows through condensation and damage to soft furnishings by being in a humid environment is, along with the potential health benefits of owning a dehumidifier (less mould spores etc.), one of the main reasons for purchasing one. Estimating the annual cost of these damaging effects is very difficult as it will vary wildly depending on the house, however a 5L tin of paint per year at £30 doesn’t seem excessive.
- Before we took the plunge and bought a ‘proper’ dehumidifier, we spent just as much on stop-gap measures such as anti-mould sprays and paints, boxes of zeolite material that capture water vapour and a whole myriad of other products. We realised that while most of these items helped in the short term, they were really only papering over the cracks and we’d be spending money almost incessantly on these items while we lived in the house. So we decided to bite the bullet and buy a dehumidifier, a once off purchase that ensured we fixed the problem once and for all. Again, for our very rough calculations, let’s say you spend £20 on these per year.
Costs Versus Benefits Of Owning A Dehumidifier
OK, so we’ve taken a look at both the positive and the negative sides of owning a dehumidifier, lets do some lifetime cost analysis, a ‘lifetime’ being 10 years, which is about how long you can expect a modern dehumidifier, if looked after properly, to last:
Costs Of Owning A Dehumidifier
- Initial purchase cost £150, £15 per 10-year lifetime
- Electricity costs, between £25 to £100 per year once the machines is ‘bedded in’, depending on the wattage of the machine, size of home and humidity levels
Total Dehumidifier Cost = £40 to £115 Annually
Money Saved By Owning A Dehumidifier
- You can turn your thermostat down by at least 1 degree, saving at least £65 per year
- Dryer air takes less energy to heat, saving £1.40 per year
- Reduce ventilation that was previously required, saving £30 per year
- Reduce damage to walls, windows and furnishings, at least £30 per year too
- No need to spend on mould sprays, expensive paints etc, saving at least £20 per year
Total Dehumidifier Benefits = at least £146.40 Annually
Therefore, Total Money Saved By Owning A Dehumidifier Is Between £31.40 – £106.40 Per Year
Conclusions
So unsurprisingly, a website that advocates the use of dehumidifiers comes out in favour of dehumidifiers! However, I think if you take a look at the calculations above you’ll see that we aren’t wildly off the true cost of ownership, or at the very least you should now understand that owning a dehumidifier is a pretty sound investment. Take a look at our favourite dehumidifier here.
Do you agree with my analysis? I’d be really interested to hear your thoughts.
Thank you for your informative article. I shall use mine more now that I know it’s cheap to run. You make a number of other excellent points too. Thanks again
Great blog Sally. Just bought the Ecoair DD122 Classic MK5 as our latest home is quite humid, my husband has been sneezing much more and his allergies (which he managed to keep under control) have become worse.
It’s great so far and to compare with your calculation and running cost analysis here are my figures:
our electricity costs 11.48p/kW
so on high setting 580w it costs 53p/day to run for 8 hours and on the low setting it costs 28p/day
More than happy with this as my husband is feeling much more comfortable. It’s early days, so we mostly have it on automatic, which means it’s running on high consumption as it dries out the house. This means it will cost just over £8/month on 300W and £16/month on 580W
Hopefully when the house dries out we will not need to run it for so long nor on the high setting, which will considerably reduce the initial running cost.
i have owned a scandinova dehumidifier for 25 years ,this machine i thought at first was a gamble because they where not recognized back then ,anyway this machine is only 150 watts but when you see the amount of water it takes out of your house you wouldnt believe it ,this machine was made in Denmark ,every couple of years i strip this machine down and clean it ,but i would love to get hold of another one thee exact same machine ,but it seems this company has gone ,if you know anything about this company could you inform me thanks
Hi Leo,
Sorry for the late reply, somehow I missed your comment… I have no idea what company you’re referring to unfortunately, although what sometimes happens is that the same machines are available in the UK, just under a different brand name. Could this be the case here?
As an alternative, Ebac are known for building some very reliable machines and come with a 5 year guarantee, check this page out for more information.
Hi
I have a situation where in my utility I keep getting condensation and mould starting to appear and black on my window frames from the washing I am trying to dry on the clothes horse. I do have a tumble drier but as you know not everything can go in. The washing seems to take forever to dry and the condensation etc is getting worse. I have a dehumidifier which people say to use as it will take the wetness out of the clothes and dry them quicker and at the same time not cause condensation. I tried this yesterday for the first time and it seemed to work. I was just a little anxious of the cost I would be running up using the dehumidifier – I set it on automatic. However, my husband will not let it be on overnight. What are your thoughts/advice?
I look forward to your comments
Thanks
Hello Claire,
Thanks for getting in touch!
I’d like to know what you’re wanting the dehumidifier for. Are you wanting it to control the humidity in the whole house or just in the utility? If it’s just the utility then to minimise the amount of energy you’ll use I’d recommend tightly sealing the room of draughts, both from the outside but also the rest of your house as the air there will be more humid and will try to diffuse in, once the dehumidifier is running. Keeping the whole house at the right humidity does bring health benefits though.
It sounds like you’re wanting to both dry clothes and remove the mould and condensation. If you just want to dry the clothes then the dehumidifier will do this over a set period of time and doesn’t need to be on 24/7, although it will not be particularly efficient (and slower) as it’ll likely have a long way to reduce the humidity when it initially gets switched on. However, if you’re wanting to remove the condensation then you’ll need to keep the humidity below the dew-point for the whole day and this will require the machine switched on 24/7. Although, you could get away with just having the machine on overnight as the worst condensation occurs in the morning when it’s coldest outside. If you have the right electricity tariff you may also find that your electricity is cheaper overnight too and so this is another bonus with just running it overnight. If you want to remove the mould and stop it coming back then you’re going to need to run the dehumidifier 24/7 to keep the humidity maintained below 60%RH, which is where the mould can’t grow (see this article for more).
Remember that while a dehumidifier’s fans are running constantly, the actual dehumidifying process is not once it is ‘bedded in’ to your home (takes a good few days of it being switched on). The machine only dehumidifies when it needs to, so the majority of the time (providing your home is well-insulated) it isn’t using very much energy. This means that it can be surprisingly efficient to run a dehumidifier 24/7, because it doesn’t have to work very hard, compared to turning it on for a few hours every day, which means it has to work very hard for those few hours.
I hope that helps. Good luck with the negotiations!
Hi,We live in a one hundred year old detached property. Our son’s bedroom has 3 external walls which in the winter appear to be very cold. When we purchased the property many years ago the room was treated for penetrative damp and appropriate replastering took place. One wall in particular, the one he sleeps next to, has shown signs of mould and the paint has peeled severely. This bedroom is next to the bathroom and we are at pains to stop condensation reaching his bedroom
We are encouraging our son to keep a window slightly open during the day / keeping a dehumidifier on low over night – could you please provide further advice..
Many thanks
Hi Jackie,
Condensation forms because warm air holds more water than cold air and so when the warm humid air hits the cold surface of an exterior wall or window, the air cools and can no longer ‘hold’ the water and so the liquid water is deposited on the cold surface.
With this in mind, the two best ways to clear the condensation are to either warm the walls/ windows, which isn’t practical, or to reduce the amount of water being ‘held’ in the air (i.e. humidity). To make the air dry enough to not release water on to cold surfaces you need to get the humidity in your son’s room to at least 60% relative humidity and on cold nights the humidity will need to be lower (because the walls/ windows are colder), possibly around 45%RH.
It sounds like you have a manual dehumidifier, with a ‘low’ to ‘high’ dial. Assuming this is a full-sized machine, generally speaking, ‘low’ on these machines means that the dehumidifier will aim for around 80%RH, which is too high for the UK. To get the humidity to 60%, you’re probably going to need to set it to just over ‘medium’ power, and to get it to roughly 45%, on ‘high’.
However, I would also recommend leaving the machine on all day, rather than just at night as it’ll have a big job on it’s hands to clear the humidity quickly enough to make a difference, even if the room is sealed.
With regards to leaving the window open, have you got a vented window in the room? If so, check that it’s open and just use that. If you don’t have a vent there, I wouldn’t leave it open, as you’ll simply lose too much of the ‘dry’ air you’re creating in the bedroom to the outside. Assuming the dehumidifier is powerful enough and you’re leaving it switched on 24/7, I would leave the bedroom door open to encourage ventilation.
Leaving the dehumidifier on all the time isn’t as expensive as you might think, because, while the fans will be on permanently, the dehumidifying parts will not (with most modern machines). Whereas if you’re just switching the machine on overnight, it will probably be having to dehumidify hard all through the night.
Have a look at this article on stopping condensation if you’d like more information.
Good luck with the battle!
I have been using dehumidifiers for approximately 8 years now and wouldn’t be without one! During the night it helps substantially with reducing blocked nasal passages. On the very odd occasion I have forgotten to swtich it on, both myself and my husband’s nasal passages are much more blocked.
That’s very interesting Marion, I wonder why that is? I’m going to have to investigate!
Again we have been using dehumidifiers for many years in both our homes and I can concur that your cost benefit analysis is very conservative on savings. Apart from what has been said so far having no musty smells no damage to decor from mould and condensation is a major benefit when arriving at a place that has not been lived in for a while. In my view for asthma sufferers such as myself they are a must have. We have always used Ebacs they are excellent machines albeit more expensive than most. They all have very reliable automated humidistat’s and I would recommend the models have an constant drain pump. For the uninitiated this means with aid of the constant drain kit you can just leave them on and they will work away keeping the humidity just right. You just need to be aware that they don’t work as well at low temperatures below 10 degrees which is not a problem in most homes but it is if the heating is off for some time in which case just turn it off until the heating kicks in or put a timer on the plug.
Hello. We live in a large Edwardian house with 5 bedrooms and the Rh is usually around 55% but we suffer with bad condensation on the single glazed leaded light windows.
I have just purchased an ecoair DC18 which has been on full blast for the past two days and the condensation on the windows has almost been eridacated.
What would be the best settings going forward once the humidity levels have settled down.
Any advise welcome and a happy new year.
Rgds
Kevin.
Hello Kevin, great to hear you humidity problems are disappearing!
There isn’t a straightforward answer to that question unfortunately. The ideal home humidity from a human perspective is roughly 40-50% RH. However at 50% RH you could still get condensation forming on the windows in winter.
I’d set the DC18 to run at 50% and see if you still get condensation forming. If condensation still forms then take it down to 45 or even 40% RH until the condensation no longer appears.
The DC18 is an efficient machine, so if it was me I’d leave it running constantly. You could utilise the timer function to potentially save energy, but in those 2 or 4 hours the machine will be going full pelt (reducing the energy savings) and having the humidity yo-yo isn’t good for health or the home.
Thanks for leaving a comment.