If you’re noticing water stains on your walls, condensation on your windows, mould lurking in your shower or a general musty smell, a dehumidifier could be the solution. Buy the wrong one, though, and it won't do much to tackle your damp problem.
Our expert guide and buying tips will explain what your options are, and take a closer look at whether you need a refrigerant (compressor) or desiccant dehumidifier. To help you choose wisely, we've also highlighted the best dehumidifiers we've tested and the key dehumidifier features to look out for.
Read on to avoid overspending, or ending up with a dehumidifier that's not suited to your needs. Whether you're on a budget or want to spend more, we'll help you to find the most appropriate dehumidifier.
Want to head straight to our high-scoring dehumidifiers? Check in with our full selection of dehumidifier reviews.
Best dehumidifiers for 2022
We’ve tested a range of dehumidifiers from different brands – including DeLonghi, Ecoair, Ebac and Meaco – to uncover the best.
Refrigerant vs desiccant dehumidifiers: what’s the difference?
Refrigerant (or compressor) dehumidifiers
Refrigerants are more popular in the UK. They work by creating a cold surface; when warm, damp air comes into contact with the cold surface, condensation forms and drips into the water tank.
Desiccant dehumidifiers use an adsorbent material to extract water from the air, in a similar way to a sponge. The desiccant is regenerated by an internal heater, and the moisture drips into the water condenser. As they're not reliant on the temperature in the room being warm, desiccant dehumidifiers work more effectively than refrigerant dehumidifiers in colder temperatures of 15°C or less.
Desiccants release more heat into the room, which might be nice if you want a mild heating effect. This isn't necessary in a home that's already heated, however.
If you're looking for a dehumidifier for an unheated garage, conservatory or other outbuilding, you should generally opt for a desiccant.
Dehumidifier features to look out for
Continuous-drain facility Many dehumidifiers allow you to connect a hose and flush the collected water away to a low-level drain. This will save you having to empty the water tank, or prevent the machine from getting full and switching off if you're not around to empty it. Note that dehumidifiers with this function often don’t come with a hose in the box, so you’ll probably have to buy it separately.
Humidistat Most dehumidifiers have one of these. A humidistat monitors moisture levels in the air and adjusts the dehumidifier to maintain the humidity level you’ve selected. Some models also have a more nuanced auto setting, where the machine adjusts its settings according to its idea of the most appropriate relative humidity.
Integrated cord storage This is handy for saving space when the dehumidifier isn’t in use, and removes the risk of tripping over a sprawling cable.
Timer Allows you to program the dehumidifier to turn on and/or off after a specified time. This could help you to save money if you're on a tariff offering cheaper energy at certain times of day, or if you want to leave the dehumidifier on for a few hours after going out, but you don't need it on all day.
Wheels/castors These could come in useful if your dehumidifier is heavy – they can weigh from 6kg to more than 16kg.
Night mode Dehumidifiers can be noisy machines. If you intend to run it at night, look for a dehumidifier with a 'night mode' or a 'silent mode'.
Smart features So-called 'smart' dehumidifiers can be controlled via a smartphone app as well as the standard control panel. This could come in handy if you want to turn your dehumidifier on or off or adjust the settings, such as fan speed, while you're in another room or even out the house. Keep in mind that smart models tend to be more expensive.
Size or capacity
A dehumidifier's size or capacity describes how many litres of water it's able to extract from the air each day (which is different to the water tank capacity). Dehumidifiers for homes range in capacity from seven to 25 litres.
The best-sized dehumidifier for your needs depends on the size of the space you want to use it in; how many people are living in the home generating moisture through activities such as cooking, washing and doing laundry; and the extent of your damp problem.
7-12 litres – small capacity. Suitable for a single person living in a small flat, looking for a lightweight and portable machine to tackle a mild damp problem.
14-16 litres – medium capacity. Suitable if there are more of you creating moisture through activities such as showering, cooking and washing clothes at home, and/or your damp problem is more severe.
18+ litres – large capacity. A sensible choice if you have a lot of moisture that you need to get rid of fast. For example, clearing up after a flood or dealing with lots of water in the air through drying laundry indoors.
Because desiccant dehumidifiers can be more powerful than refrigerant models, they can cover a larger area than a refrigerant of the same claimed capacity. Even within the broad categories of refrigerant and desiccant, two models with the same claimed capacity could vary enormously in effectiveness – the only way to be sure which dehumidifiers are going to do a good job is to check our expert dehumidifier reviews.
You should also bear in mind that manufacturer claims about water extraction rate are often based on conditions you're unlikely to experience in your home. For refrigerant dehumidifiers, manufacturers frequently base their claims on 30ºC and 80% relative humidity – conditions that better represent a tropical rainforest than a typical British home.
If you've got a small home, you won't want a hulking dehumidifier taking up precious space. The smallest dehumidifiers have a capacity of seven to 10 litres. Size-wise, these smaller models will range from 18 x 38 x 18cm to 36 x 55 x 33cm (W x H x D).
Laundry mode on a dehumidifier
If you don’t have a tumble dryer and it’s too cold to hang wet clothes outside, a dehumidifier can help you to dry your clothes. Hanging clothes on a radiator can cause condensation, so you should always avoid doing that.
Some models come with a laundry setting, but you can use any dehumidifier for this if yours doesn't have one. Many laundry settings just whack up the power to max for a set time, although some are designed to save energy by optimising the machine's performance so it doesn't work harder than it needs to.
Are dehumidifiers eco-friendly?
Dehumidifiers can use a lot of energy, especially if used inefficiently. The electricity required to power a dehumidifier can be generated from a mixture of burning fossil fuels, renewables, gas and nuclear. But as this is mixed up in the grid, you can’t guarantee it’s coming from a renewable energy source.
There are some simple ways to make sure your dehumidifier is not working harder than necessary:
Choose the right capacity for the size of your space, the amount of people living in it and the severity of your damp problem.
Keep the windows shut when you’re running a dehumidifier, so damp air from outside isn’t drawn in.
If available, make use of timer or automatic shut-off features so the dehumidifier isn’t running continuously while you’re out of the house or asleep.
Look at our test scores. Every dehumidifier we review has an energy efficiency rating, so our highest-scoring models are most likely to be the least wasteful.
Should I buy a second-hand dehumidifier?
You could save some money by buying a dehumidifier second-hand. If you’re purchasing from a private seller, be aware that, unlike retailers, they are not obliged to proactively highlight any faults. They should tell you if you specifically ask though.
Although you could be making an initial saving, you might have to spend more money repairing a second-hand dehumidifier or buying replacement parts such as filters or castor wheels. For older dehumidifiers, replacement parts might not be available, so it’s worth checking before buying a used model.
Dehumidifier manufacturers have started to update their older models or create new ones using refrigerant gases with less of a global warming impact, such as R290. If you buy an older second-hand model, it may use a HFC (hydrofluorocarbon) refrigerant that can be a potent greenhouse gas if leaked.
If you’re thinking about getting rid of your dehumidifier, it’s important to do so in a way that isn’t harmful to the environment. If sent to landfill, the dehumidifier could release the refrigerant into the environment. In some models, particularly older ones, these can be HFCs, which are greenhouse gases.
Look for the crossed-out wheelie bin symbol on your dehumidifier, as this is an indicator that it can be recycled. You may have to remove the filter though and put it with your normal household waste, as this might not be suitable for recycling. This information should be available in the dehumidifier’s manual.
To recycle your dehumidifier, check with your local council to see if it accepts kerbside collection. You may also be able to drop it off at your local recycling centre. If you’re buying a new dehumidifier, some retailers might even take your old one away.
Dehumidifiers can cost anything from around £40 to £450, with the amount you spend based on the dehumidifier’s capacity and extra features.
Models that cost less than £150 tend to have a capacity of 10 litres or less. Cheaper dehumidifiers are also less likely to have castors, wheels or a laundry setting.
However, most models have a built-in humidistat regardless of price. This allows you to specify a relative humidity (RH) that you want the dehumidifier to try to create in the room. Some also have an auto setting. How this works will vary from brand to brand, but generally speaking the dehumidifier will monitor and regulate conditions in the room according to what it deems to be the most appropriate RH at that point in time.
Where to buy a dehumidifier
When shopping online, make sure you’re dealing with a reputable seller. Check the retailer's returns policy and also have a look at some customer reviews.
Popular retailers that stock dehumidifiers include:
Argos stocks a selection of dehumidifiers from Challenge, Dimplex, Ebac and Meaco. Prices range from £50 to £300.
Screwfix sells dehumidifiers from Blyss, Ebac and Essentials. The retailer lists the Blyss WDH-316DB as a 'top seller' – it has a 2.4-litre tank and has an automatic shut down.
Amazon has a vast selection of dehumidifiers for you to sift through. Big-name brands include EcoAir, Inventor and Meaco.
B&Q has dehumidifiers that start from £40. The priciest model at the time of writing is the £260 Princess SMART 20L.
Discover which retailers are rated highly by Which? members with our expert guide on the best and worst shops.
How to dry clothes indoors during winter
If you’re running a dehumidifier, keep the door to the room the dehumidifier is in open, so that air can circulate through your home. But close the window, so that damp air outside – which will migrate towards drier spots – isn’t drawn to the drier air indoors.
Open your window for 15 minutes after showering or cooking, though, and longer if you’re not then going to be using a dehumidifier. It’s tempting to keep your windows shut tight in winter, but then condensation has no means of escape.
Don’t hang clothes directly on a radiator as direct heat could damage delicate fibres, add to your heating bill and even, depending on the heater, be a fire hazard – as well as causing condensation. Use a clothes airer instead. You can buy ones that hook over your radiator for as little as £5 on Amazon, larger ones from £15 and heated ones from £22.
Resist the temptation to put clothes that aren't quite dry back into your wardrobe. The smaller your home, the more of a hurry you might be in to tidy things away. But getting mould out of a wardrobe can be a nightmare: you can’t just set to it with bleach and a stiff-bristled brush, as you could damage the wood. Prevention is better than cure.
Moisture absorbers (also known as damp traps) contain crystals that absorb moisture and dissolve as they make contact with air. These machines often take the form of little plastic tubs with two levels – the upper layer contains the crystals and the bottom layer collects the liquid which drips through from the top.
You can use a moisture absorber in a basement, bathroom, bedroom, garage, kitchen, living room or any other room of your house that has a recurring damp problem. Some are designed to work in cars – check the instructions before buying.
Moisture absorbers are very cheap and you can even find them for as little as £1. To see how effective they are, we asked volunteers who had damp in their homes to try out the following models:
Kontrol Streamline Moisture Trap 1L – £5.79
Kilrock Spiraflo Moisture Absorber – £6.99
Unibond Aero 360 Moisture Absorber – £9.99
Minky Damp Guard – £11 (includes four refills)
One of our volunteers tried the Kontrol Streamline Moisture Trap in a basement flat that barely gets any sun in winter. They told us: ‘The only heater in that room is very poor, too, so I can’t get a consistent temperature. When I put the heater on, it gets warm very quickly, but, as soon as I turn the heater off, the room cools down really quickly. Condensation often builds up on the windows during the winter (see below), particularly in the morning.’
The moisture absorber definitely reduced the condensation on the windows. Before placing the moisture absorber on the windowsill, the windows would totally mist up (as you can see in the picture above), and puddles of water would collect in the corners of the windowsill. After using the absorber, there was only a small amount of condensation around the edges of the glass (as in the picture below).
Our trials showed that moisture absorbers won’t do much to reduce damp in a room that’s routinely used for drying laundry. So moisture absorbers can help with small day-to-day damp issues, but shouldn’t be relied upon for any serious damp-busting.
Once the crystals in your moisture absorber have dissolved into liquid, all you need to do is empty the liquid into a toilet and flush it away. How long each packet of crystals lasts will depend on the moisture levels in your home. If your issue is only minor (or you can’t see or smell damp but are just buying one to be on the safe side), you may only infrequently need refills. If you find you’re often having to buy refills, it may be time to invest in a dehumidifier.