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If your home suffers from damp patches or mould, the root cause is often excess moisture. Sometimes the construction of the building, poor insulation, ineffective drainage or a lack of ventilation are to blame, while cooking or drying clothes inside can have an impact. Either way, once your humidity level gets much above 60%, it’s bad for both you and your home.

It’s bad for you because bugs and mould love high humidity levels. Dust mites and mould spores thrive and can trigger allergies, skin irritation and respiratory problems such as asthma. Moods and general wellness can also be affected.

It’s bad for your home because you’ll get patches of damp and mould on your walls and ceilings – some superficial, but some creating lasting damage. You might even find your favourite things affected: books, clothing, furniture, printed art and old records can all be wrecked by mould and damp.

While opening windows and fixing up your home can help, the best way to combat excess humidity is often a dehumidifier. It will dry out your rooms, fight back against the damp and protect your walls and precious things from being affected.

All dehumidifiers do the same basic job of removing excess moisture from the air. However, there are three different technologies that do all the hard work.

Compressor dehumidifiers work in much the same way as a fridge or freezer. They draw in air and cool it, condensing any moisture as it passes across a refrigerated coil. The water then drips off into a water tank below, while the air is reheated and released into the room. Compressor dehumidifiers can be noisy and may use more energy than other types, although new compressor technology and refrigerants are bringing improvements on both counts. They’re most efficient at warmer temperatures of 20°C and above, and your best bet if you need to remove lots of moisture from a larger space.

Peltier dehumidifiers also cool the air and condense the moisture content into water; but they do it using a cold heat-sink rather than a compressor. They’re not as effective as compressors, removing smaller amounts of water in a given time, but they’re quieter and more energy efficient. Peltier dehumidifiers tend to be compact, lightweight units designed for smaller spaces.

Desiccant dehumidifiers don’t use a heat-sink or refrigerated coil to condense excess moisture, but instead draw the air across a wheel made from a desiccant material, which sucks the moisture out. As the wheel turns, moisture drips into the tank, while the damp patches are heated to dry them out again, warming up the air. Desiccant models tend to be expensive, but they’re generally quieter in operation than compressor dehumidifiers and more effective at lower temperatures. In fact, they’ll work in temperatures under 10°C, where compressor and Peltier units won’t work at all. If you need to dry out a loft or garage, you really need a dessicant model, but they can also be useful in a cold British winter for drying out your colder, damper rooms.

It all depends on how much space you need to dehumidify. Dehumidifiers are often rated in terms of their extraction rate: how much water they can remove from the air in a single day. This is separate from their water tank capacity, which covers how much water they can store before you need to empty them out.

An extraction rate of around five to ten litres per day is fine if you’re dehumidifying a small to medium-sized room in an average UK home, but if you want to dry out larger rooms where you spend more time, you might want to go up to 10 litres and beyond. Push that further to 15, 18 or 20 litres and you can dehumidify large rooms or even a flat, terraced house or a floor of a detached house or semi.

If you’re only planning to dehumidify occasionally – for a few hours here or there in a kitchen or bathroom, for instance – you can get away with a mini-dehumidifier with an extraction rate of under one litre. It will be cheap to buy, cheap to run and perfectly effective. The same applies if you’re trying to fight damp or mould in a smaller area, such as a wardrobe, utility room or box bedroom.

If you’re pulling out 15 to 20 litres per day, the dehumidifier needs to have a tank with the capacity to handle it or you’ll be emptying it out every few hours. Three litres is the absolute minimum, while five or six litres will give you a bit less emptying to do.

Dehumidifiers don’t have to be noisy, and there are some good near-silent options. They will work discreetly in your home without interfering with your sleep or work, so a quiet mode or eco mode is well worth any extra, particularly if it will save you some cash in running costs.

Laundry modes are another great feature. Wet laundry drying on a rack or radiator is one of the most common causes of excess moisture in the winter months, and models with a specific laundry setting are designed to suck the water out of your drying clothes at a faster rate and prevent it from adding to the room’s humidity. They might even create airflow across a drying rack. Your clothes should dry quicker, too, making this a more eco-conscious alternative to slinging them into a tumble dryer.

This varies according to the design, size and extraction rate. Generally speaking, desiccant dehumidifiers use more energy per hour than a compressor model, but can also work more effectively at removing moisture, which means costs tend to even out.

However, it’s worth looking out for newer and more energy-efficient designs. For example, Meaco’s MeacoDry Arete One 20L costs around 6p per hour to run, based on an electricity rate of 28.3p per kWh, while some models will cost significantly more at the same rate. Use your dehumidifier daily for a couple of hours and the difference soon mounts up.

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Price: £110 | Buy now from Amazon

This compact dehumidifier from UK manufacturer Inventor crams in plenty of moisture-fighting power. It will remove up to 12 litres per day, filling into a 2.1-litre tank, and there’s a hose for continuous drainage if you’ve got a drain within easy reach. The “Silent” function is arguably a misnomer: it’s quieter, but at around 41dB there’s still a noticeable fan hum. Otherwise, this is an easy-to-use dehumidifier that does the job, with a digital humidity indicator, built-in air filtration and an automatic shut-off when the tank gets full.

At 11.4kg, it’s just about light enough to move from room to room, and the smart defrost function means it will work in cooler environments than many compressor models. There’s also an automatic timer to turn it on and off when you’re not in the room, plus a continuous dehumidification mode you can use when you have a damp room, spillages or clothes to be dried. If you have a larger house or want to dry multiple rooms at once, you might want to step up to a 20-litre model, but this is a brilliant no-fuss option at a reasonable price.

Key specs – Dehumidifier type: Compressor; Tank size: 2.1 litres; Extraction rate: 12 litres per day; Dimensions: 42 x 32 x 21.5cm (HWD); Weight: 11.4kg; Warranty: 2 years

Price: £160 | Buy now from Meaco

The latest model in Meaco’s dehumidifier range is a compact version of the superb Arete One, dropping the extraction rate down to 10 litres per day, but reducing the size of the unit to less than 50cm high. Not only is the Arete One 10L physically unobtrusive, but it’s also impressively quiet. While we measured noise levels of around 42dB with the fans running at full tilt, these rapidly decreased to well under 40dB, which is about as close as dehumidifiers get to silent. In its night mode, the Arete One 10L can go as low as 35dB.

Just like the larger model, the 10L has a laundry mode to dry your washing, and can double as an air purifier with the bundled HEPA filter inserted – although we found it a little less effective in our air-purifying tests than most dedicated models. As a dehumidifier, it’s hard to fault, working efficiently in small and medium-sized rooms to reduce humidity levels and get rid of mould and moisture. Throw in the intuitive controls and easily removable water tank, and this is the best of the compact options, and ideal for smaller rooms and homes.

Key specs – Dehumidifier type: Compressor; Tank size: 2.5 litres; Extraction rate: 10 litres per day; Dimensions: 47.2 x 23.7 x 31.9cm (HWD); Warranty: 5 years parts and labour

Price: £46 | Buy now from Amazon

Small and lightweight, this budget dehumidifier is easy to carry around the house and a breeze to empty once its one-litre tank is full. Using Peltier technology, it’s quiet too, with one-touch controls that make it one of the easiest dehumidifiers on our list to operate.

Although compact, it’s more powerful than it looks, packing enough of a punch to stop your kitchen from getting steamy while you cook or to clear the mist from a busy bathroom. It can only extract around 450ml per day, so it’s not up to handling larger spaces, but it’s ideal for less intensive use or smaller rooms.

An internal LED light that cycles through a rainbow of colours is a nice touch, and it turns red when the tank is approaching full (800ml), so you’ll know when it needs attention. Don’t worry if you don’t get to it in time, though, because it shuts off automatically when full. The machine stays very clean while it works, but there’s an easy-to-remove panel on the back for clearing out any gunk.

Key specs – Dehumidifier type: Compressor; Tank size: 1 litre; Extraction rate: 450ml per day; Dimensions: 26 x 15 x 15cm (HWD); Weight: 1.3kg; Warranty: 1 year

Price: £269 | Buy now from Amazon

This Ebac model gives you a step up in drying power from the smaller units; with an 18-litre extraction rate and a 3.5-litre tank, it can combat moisture in a three- to four-bedroom house without any worries, and help banish mould and condensation. In fact, its manufacturer claims that it’s been designed specifically for the UK climate, and that it will take more water out than other brands with lower running costs. Ebac’s intelligent Smart Control system constantly monitors moisture levels in your home and proactively acts to stop condensation building up before mould or damp become a problem.

At 12kg it’s heavy even before you start filling up the tank, but it’s powerful enough to dehumidify a large room or a whole floor at a time. What’s more, it has a laundry boost feature to help get the washing dry faster, a timer function and built-in air purification through a carbon filter (though not a HEPA filter as you’ll find in stand-alone devices). Other dehumidifiers are more powerful or quieter and less obtrusive, but the Ebac is a great option for medium to large-sized rooms or an average three-bedroom home.

Key specs – Dehumidifier type: Compressor; Tank size: 3.5 litres; Extraction rate: 18 litres per day; Dimensions: 54.5 x 34 x 26.5cm (HWD); Weight: 12kg; Warranty: 2 years

Price: £299 | Buy now from Amazon

Don’t get too excited about this dehumidifier’s smart capabilities. You can connect it to your smartphone or tablet via Bluetooth, but the app is little more than a glorified remote control with only basic scheduling features and no way to integrate with existing air quality metres you might have hooked up. That aside, it’s a well-designed and effective dehumidifier, capable of extracting up to 20 litres per day into a larger-than-average 6-litre tank. We found this surprisingly easy to remove from the rear of the machine when full, with a built-in handle for carrying.

The Princess isn’t as quiet as Meaco’s Arete models, but you can live with the 46dB it puts out at its highest fan setting, or the 40dB noise levels at low. It also has a useful laundry drying feature that makes the most of the vertical swing on the air output and the powerful fan. It’s simple to control, either through the app or via the built-in controls, and you can keep an eye on the current humidity level through a subtle “hidden” digital display on the front. Rival dehumidifiers have the edge on noise and performance, but the Princess gives you a great set of features at a very reasonable price.

Key specs – Dehumidifier type: Compressor; Tank size: 6 litres; Extraction rate: 20 litres per day; Dimensions: 59.5 x 37.1 x 25.1cm (HWD); Weight: 16.4kg; Warranty: 2 years

Price: £260 | Buy now from John Lewis

High-capacity dehumidifiers are usually power-hungry and noisy, but the MeacoDry Arete One is designed to do more with less energy and a lower volume, topping out at 40dB during typical use and keeping consumption to around 200W. In fact, both figures fall dramatically as humidity levels start to drop. It’s an excellent dehumidifier for larger spaces and, unlike most compressor models, will work at temperatures of between 5 and 25°C.

Its talents don’t end there; it has a laundry mode to dry your washing and a night mode for working quietly while you get some kip, although it’s still not really suitable for lighter sleepers. It also has an air purifier mode, complete with a proper HEPA filter. Throw in easy-to-use controls and a five-year warranty, and you’re looking at one of the most feature-packed and effective dehumidifiers out there, and easily the best for medium-sized and larger homes.

Key specs – Dehumidifier type: Compressor; Tank size: 4.8 litres; Extraction rate: 20 litres per day; Dimensions: 56.2 x 37.6 x 23.2cm (HWD); Weight: 15kg; Warranty: 5 years

Buy now from John Lewis

Price: £150 | Buy now from Amazon

This EcoAir model can extract up to seven litres of moisture per day, and as a desiccant-type dehumidifier, it works at lower temperatures than your average refrigerant device.

It’s slightly louder and consumes more power than the equivalent refrigerant, but can also run more effectively over shorter periods. That makes it a good bet for drying clothes or using in an outside office, garage or workshop where damp is becoming a problem, and it’s relatively lightweight and portable to boot.

With a two-litre tank, it might need emptying more regularly than some models, but there’s a 1m hose if you need continuous draining into a sink or drain. And while there’s no timer, you do get a laundry mode and a choice of quiet and turbo functions, and the rotary control is – as advertised – simple and easy to use.

Keep it running all day long and the costs could mount up, but this is an excellent dehumidifier for situations where a refrigerant model just won’t work.

Key specs – Dehumidifier type: Desiccant; Tank size: 2 litres; Extraction rate: 6 litres per day; Dimensions: 48.5 x 29 x 17.5cm; Weight: 6kg; Warranty: 2 years

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