Swan Activair 20-litre dehumidifier reviewon January 18, 2024 at 10:28 Tech Advisor

At a glance

Expert’s Rating


Easy to useEffective9p an hour to run


No HEPA filterHeavy

Our Verdict

This handy dehumidifier is simple to use and will make a huge difference to your home air quality if you struggle with damp air or damp clothes. The filter isn’t HEPA standard but if that’s not an issue for you, we’d recommend it.

Price When Reviewed


Best Prices Today: Swan Activair 20-litre dehumidifier


If your home suffers from damp or you’re trying to avoid using a tumble dryer to dry your clothes, a dehumidifier is a good option. It’ll help to prevent mould and damp walls, and your clothes will dry much more quickly. Most importantly, it’ll cost you far less than running a tumble dryer.

In this review, we’re taking a look at British brand Swan’s Activair 20-litre dehumidifier, which is a widely available appliance.

Design & Build

Operation range of 5°C-35°C

For a room size of 12-16sqm

Dehumidifiers tend to be functional looking, at best, but the Activair is at least discreetly designed, with a glossy finish and rounded edges that prevent it looking too boxy. Its measurements are 34.2 (H) x 25.1 (W) x 56.1cm (H).

In my experience, the Activair does exactly what it promises

It’s heavy at 13.2kg, which means you won’t want to be carrying it up and down the stairs often. It has nook handles built into the sides, so you can lift it, although these aren’t ideal for lugging it around. But, as it stands on casters, it’s easy to move it from place to place on one floor.

The appliance’s 20-litre capacity doesn’t refer to any internal capacity. It means that the appliance can remove 20 litres of water from the air in a 24-hour period, assuming a room temperature of 30°C and a relative humidity of 80%. In my experience, the Activair does exactly what it promises.

It has an operational temperature range of 5°C-35°C and is suitable for a room size of 12-16sqm, which means it should cope well in all but the largest domestic settings. If you have a damp ballroom to dry out, you’ll need to look elsewhere.

The dehumidifier’s controls are on a soft touch panel on top of the appliance. There’s a power button, a timer and humidity setting, both of which you control via the up and down keys, a fan speed setting and a swing setting, which sets the deflector moving to change the angle of the current of air expelled.

Emma Rowley / Foundry

There’s also a simple digital display, which indicates the room’s current humidity level, with a minimum humidity of 35(%) and a maximum of 95(%). If you set a timer, it’ll display the number of hours you’ve set it for (it allows a setting of up to 24 hours) and if you change the humidity, the setting you’ve selected will be shown.

The machine’s default setting is to achieve 40% humidity, but you can easily adjust it. We previously tested the Meaco Arete One, which intelligently adjusts to the moisture level in the air. The Activair won’t do that but it’s significantly cheaper than the Arete One, and easy to use as well, so you may think the trade-off is well worth it.

The water the dehumidifier pulls from the air has to go somewhere, and that’s into the machine’s 4-litre water tank. You’ll need to empty the tank regularly, which is straightforward to do. Just pop it out from the back of the machine and empty it into the sink.

Emma Rowley / Foundry

If you forget and the tank fills up, a red indicator will blink and the machine will stop. However, I did forget to empty it once and it didn’t stop until a small pool of water had formed at its base.

You can use the dehumidifier for continuous drainage, but you’ll need to provide your own hose – and you’ll need to place it near a drain.

The Activair has a multi-stage filter at the back. It’s not HEPA standard, so it won’t clear the air of tiny particles and help with allergies, but it will help to prevent dust and pet hair being blown around.

Emma Rowley / Foundry

Performance & Features

Easy set up


The Activair is easy to set up. The most difficult part is getting the heavy appliance out of the box. Then you need to find a spot to stand it with a 20cm clearance around it and plug it in. And that’s it. It’s not a connected appliance and it doesn’t come with a remote, so there’s nothing else to consider.

The Activair has done an incredible job of banishing damp from the bathroom and ensuring clothes dry quickly

Unluckily for me, but luckily for this review, my bathroom extractor fan conked out a short while after the dehumidifier arrived. As I have an internal bathroom without a window, the dehumidifier has been absolutely necessary for the last couple of months. Without it, I’d have had to resort to the tumble dryer for clothes and bedding, and I’d be bleaching the bathroom endlessly to stop mould appearing around the shower.

As it is, the Activair has done an incredible job of banishing damp from the bathroom and ensuring clothes dry quickly. I’ve switched it on every morning after showering, and again whenever drying clothes, towels or bedding, and it’s kept the air at a comfortable humidity level and mould and mildew at bay.

Maintenance has been straightforward as well. Apart from emptying the tank (when I remember to do so, at least), I’ve also removed the filter cover and cleaned the filter by hand, which largely involved peeling away a fairly impressive amount of cat hair, courtesy of our extremely annoying pet.

But what will the Activair cost you to run? It’s a 310W appliance, which on the current UK price cap will cost you around 9p per hour to run – depending on which settings you use. It’s hard to say how long you’ll need to use it for, as it’ll depend on the size of the room and how damp it is, but I generally found that half an hour to an hour’s use after showering and the same for a load of laundry had a significant effect.   

If you know your electricity tariff, you can use an online energy calculator to get an idea of what it’ll cost you – but it’ll work out much less than using a tumble dryer.

Price & Availability

The Swan Activair has an RRP of £219.99 but is widely available for around £25-£30 less. At the time of writing, you can buy it from Amazon, Robert Dyas or direct from Swan.

At this price, it’s significantly cheaper than the Meaco Arete One 20L, which you can buy direct from the brand for £259.99. The Arete One is, in many ways, the gold standard of UK dehumidifiers and features a HEPA filter and intelligent operation. You can read more about it in our review but if you’re happy to do without these features, the Activair is a very good buy.

Should you buy the Swan Activair 20-litre dehumidifier?

This is a product that’s easy to recommend. It’s simple to use, cheap to run and does exactly what it’s supposed to. If you’re struggling with a damp home or washing that that won’t dry in the colder months, this is well worth the investment.

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