The best air coolers to chill your home during UK heatwaves – tested
They’re cheaper and greener than air conditioning, but which evaporative cooler impressed us most?
Air coolers should not be confused with air conditioning. An air cooler can lower your room temperature by a couple of degrees, while aircon can lower it by tens of degrees. So it’s important to manage your expectations. But air coolers are much more energy efficient: they use a fraction of the electricity of aircon.
Evaporative air coolers work by pulling warm air through water-soaked pads. The water evaporates, which uses energy, so the process cools the air. So while it’s not fridge-cold like aircon, the air is cooling – like a sea breeze taking the edge off summer heat.
A typical portable air conditioner uses about 1,000W (watts) of electricity (costing about 26p an hour to run, based on the July 2026 price cap). By comparison, the evaporative coolers I tested use between 26W and 87W; you could run my favourite model, the Swan Nordic (26W), for 38 hours and it would still use less electricity than a single aircon unit running for an hour.
When we’re suffering from heatwaves caused by the climate crisis, it makes sense to use less energy by choosing energy-efficient products that are effective and built to last. So I’ve tested nine air coolers to help find the best for you, assessing them in terms of size, noise, power use and, of course, how much they cool you down. Due to phenomenal demand due to recent heatwaves, the only air cooler I’ve recommended that’s currently in stock is the Morphy Richards portable air cooler.
It’s worth considering a fan too: they don’t actively cool air down, but the improved air circulation they contribute helps your sweat to evaporate faster, cooling down your body – and they’re even more energy efficient. It’s a personal choice: a powerful fan feels immediately cooling, whereas an evaporative cooler actually lowers the temperature. Personally, I favour evaporative coolers that have powerful fans built in. Most can be used as stand-alone fans without the evaporative function enabled, although the effectiveness varies.
Note that evaporative coolers (sometimes known as swamp coolers) humidify your air, so they’re not a good fit if you have damp and mould problems. They’re designed to be used with doors open and fresh air coming in.
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At a glance
Best air cooler overall:
Swan Nordic air cooler – currently out of stock
Best portable air cooler:
Morphy Richards Flexi Freeze
Best air cooler for the garden:
Shark FlexBreeze Pro Mist FA300UK – currently out of stock
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Why you should trust me
I’m triply qualified to test these evaporative coolers. First, I’m an award-winning consumer tech journalist with decades of experience testing gadgets of all shapes and sizes. Second, I have a degree in mechanical engineering. Last, but not least, I’m a menopausal woman in her 50s, as I pointed out while testing fans; I honestly can’t remember the last time I felt cold.
How I tested
I chose nine evaporative coolers, each from a different brand. For the scientific side of this test, I used a power meter to measure how much electricity (and, therefore, money and carbon) they use. From one metre away, I used a digital thermometer to measure the change in air temperature and the Sound Meter app to measure the noise. I also measured each evaporative cooler’s size.
Subjectively, I took note of everything from how cooling each evaporative cooler felt, how annoying the noise was and how easy the controls were to use. I also considered how they looked and how small they pack away for the winter, as well as the price tag.
Any evaporative coolers that weren’t collected by manufacturers were donated to Furnishing Futures, a charity that fully furnishes the empty social housing in which women and children are placed after surviving domestic abuse.
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The best air coolers
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<em>Best air cooler overall:</em>Swan Nordic air cooler
- What we love:Good looking; the most effective on test at cooling the room
- What we don’t love:Emptying is a pain because there’s no bung at the bottom
Currently out of stock
This evaporative cooler isn’t just good-looking, it’s effective. I’ve tested it before for our fans test and retested it here: I found it just as good, and it came out slightly quieter in my tests this time. It’s on castors with a rear drawer for water, and comes with two ice packs to cool the water. There’s a slot to store the remote control.
Unusually, rather than oscillating or having a swing function, the grille at the front slowly turns to alter the breeze, which is a bit hypnotic.
Why we love it
The Swan cooled the room well, by 1C in an hour, and put out a wide, cooling breeze. There are 24 fan speeds, and you can select them via the remote control.
The breeze is powerful, and its energy consumption is modest. It’s great to use as a fan, with or without the evaporative cooling, depending on the temperature. It’s also one of the quietest on test; I could definitely sleep with it running.
It’s good value and good looking, with a coffee-coloured “oatmeal” finish and wood-effect detail. This makes a nice change from the monochrome of most models.
It’s a shame that … there’s no bung on the bottom for draining the tank at the end of summer. Instead, you have to use it until nearly empty, then tip it out – although this is only once a year.
Dimensions: 29 x 24 x 71cm (WDH)
Water tank: 5l
Number of speeds: 24
Remote control? Yes
Peak noise level on test: 40dB
Power use on top setting: 26W
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<em>Best portable air cooler:</em>Morphy Richards Flexi Freeze mini air cooler
- What we love:Good-looking; works well as a fan with optional cooler
- What we don’t love:The noise is annoying
And now for something completely different. This is a personal evaporative cooler. You recharge it via USB, then stand it near you – it’s not trying to cool the whole room.
The design is modern and boxy, with no visible blades: cooling air emerges from the ring around the circular display. There’s no remote control because the cooler should be within reach.
I couldn’t measure power use because it’s rechargeable, but charging uses 10W, and the makers say it runs for up to 15 hours on one four-hour charge. Expect a three-hour runtime on the highest fan setting when cooling is switched on.
As with any evaporative cooler, cold water (you can even add ice to the tank) is wicked up pads at the rear, then air is pulled through them. The result is cooler, more humid air. The fact that it’s rechargeable means you can use it in a caravan or while camping.
At an average 30dB (measured from 1m away, as ever) on its top setting, it’s fairly quiet, but I found the noise annoying. It has a low hum when cooling is on, but it’s quieter when used as a fan.
Why we love it
This is designed for personal coolness. So I moved my test equipment nearer (50cm) and was pleased to see the temperature gradually coming down. It started at 30.6C and was down to 29.5C after 15 minutes. It didn’t drop much lower, but still, shaving more than a degree off was welcome.
Again, taken up close, the fastest air speed I measured was 2.4m/s, respectable for a fan. And that’s how I would see the Morphy Richards. It’s a personal fan that happens to cool the air down a little if you turn on the evaporative cooler. And yes, you can use it just as a fan too.
It’s a shame that … it doesn’t double as a power bank, which would be helpful for travel.
Dimensions: 18 x 13 x 30cm (WDH)
Water tank: 1l
Number of speeds: 4
Remote control? No
Peak noise level on test: 30dB
Power use on top setting: 10W to charge
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<em>Best for the garden:</em>Shark FlexBreeze Pro Mist FA300UK
- What we love:Powerful and genuinely cooling; the water’s a bonus outdoors
- What we don’t love:Misting spray gets things wet, so you can’t use it indoors
This is not technically an evaporative cooler. It works in a similar way, but you can’t use it to cool indoors with water. Instead, it’s designed to cool you outdoors by spraying a fine mist of water directly into the air in front of the fan. I found it really effective for cooling while I was sitting on the patio.
The fan is slim and elegant, with a slightly wider 35 x 35cm circular base. The big carry handle on top can be used to angle it up and down, and the fan oscillates from side to side. You can choose from three angles of oscillation or use the left and right buttons on the remote control to turn the fan.
Why we love it
The Shark is very good at cooling you down outdoors. There are three levels of mist, and it’s the kind of wet wind you get straight off the sea, making everything slightly damp but very welcome in hot weather. It’s perfect for a barbecue on a summer’s day.
It claims to reduce temperatures by up to 6C, although I can’t give a test figure because the water spray made my digital thermometer stop working. But what I can say is that it cooled me down fast. You quickly see why the water mist is for outdoors only: my clothes became slightly damp, and a small puddle formed in front of the Shark. I made a note not to use my laptop near it: it’s not for WFP (working from the patio) days.
I liked that it’s rechargeable, easy to carry around the house by the top handle, and even convertible; you can take off the tank to use it as a fan indoors and take off the pole to convert it to a desk fan.
The cordless run time is quoted as two to 24 hours, depending on fan speed, and charging time is five to six hours. I found that I could use the fan at the same time as charging it for later use.
And power use was impressively low: 14W on the top fan setting, 7W to charge the battery and 21W to do both at once. This gives many fans a run for their money. It works well as a fan, with five speeds, of which the first two were silent. It’s pricey but convenient since it’s cordless. I’d buy it for indoor use and enjoy the misting for outdoor entertaining on hot days.
It’s a shame that … you can’t use the misting indoors.
Dimensions: 35 x 35 x 93cm (WDH)
Water tank: 5l
Number of speeds: 5
Remote control? Yes
Peak noise level on test: 55dB
Power use on top setting: 21W
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The best of the rest
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Pro Breeze OmniAir 5l
- What we love:Aromatherapy is interesting; side-to-side swing works well
- What we don’t love:It’s just not cooling enough
Currently out of stock
Best for: air freshening
The Pro Breeze’s party trick is that you can add aroma to the air it kicks out: there’s a little drawer on the front for a pad, which you scent with a few drops of essential oil. Sadly, though, I didn’t find the room was particularly filled with lemon scent when I added my lemon oil.
Cooling was a letdown, too: the temperature didn’t measurably decrease, despite adding ice packs in the rear water drawer. The lowest mode is quiet enough to sleep with, at least, and there are two sleep modes that gradually reduce power.
I also liked the swing function, which blows side to side. I preferred this to the breeze mode that switches between each of the three fan levels. The breeze just wasn’t strong enough, however, no matter which mode it was in.
The unit is tall and slim with no castors for moving it around, reminiscent of a tower fan. The tower itself is just 19cm wide by 24cm deep (with a wider, circular base as specified below), so it’s fairly narrow visually.
It didn’t make the final cut because … it’s expensive and doesn’t cool enough.
Dimensions: 31 x 31 x 103cm (WDH); water tank: 5l; number of speeds: 3; remote control? Yes; peak noise level on test: 30dB; power use on top setting: 46W
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What you need to know
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How do evaporative air coolers work?
Evaporative air coolers have a reservoir of water. You can add ice to make the water even cooler. The water is wicked up into pads at the back of the cooler. Then a fan pulls warm air through the water-soaked pads. The water evaporates, which uses energy, so the process cools the air. The result is a cooling breeze that takes the edge off summer heat.
They cool the room only a little, though, so don’t expect them to drastically alter the temperature like aircon. They’re most effective in dryer environments as they make the air more humid, effectively acting as humidifiers while cooling.
Air coolers vs fans
Fans don’t actually cool the air in the room. They feel cooling because the moving air from the fan displaces the warm, humid air near your skin, which in turn helps your sweat evaporate, cooling your body down. It’s like a breeze rather than a still day.
Evaporative coolers use water to actively cool the air, but their fans are less powerful so you don’t feel the benefit of a blast of air.
For more, read our guide to the best fans
What features should I look out for?
Most fans oscillate, moving side to side by swivelling on their base, whereas evaporative coolers tend to achieve a similar effect via a swing mode, which turns the vertical louvres at the front, moving the airflow from side to side. I found this effective for variety, but the angle is narrower than that of an oscillating fan.
Meanwhile, breeze and natural modes cycle between different fan speeds to mimic the variety of a natural breeze.
Also look out for a sleep timer, which gradually reduces the power overnight.
How much does an evaporative cooler cost to run?
I’ll set out the maths. For each evaporative cooler on test, I measured its power use on the top setting, in watts (W). Electricity costs are in kWh (kilowatt hours). If, for example, you were using a 30W evaporative cooler for five hours, it would use 30 x 5 = 150Wh or 0.150kWh of energy.
The energy price cap for 1 July to 30 September 2026 is 26.11p a kWh. So that’s the price to use 1kWh of energy. Multiply 26.11p by 0.150kWh, and you’ll discover it costs just below 4p to run your evaporative cooler for five hours, or about £14 to run it this much every day for a year.
Evaporative coolers are very cheap to run, then, and they may keep you cool enough that you can dodge air conditioning. Aircon uses significantly more electricity: pounds a day, not pennies.
Broken tech is also awful for the environment. The evaporative coolers featured here have a one- or two-year guarantee. Longer guarantees are better: the makers are more likely to have built the product to last.
How to clean your air cooler
Unplug the cooler and use a microfibre cloth, dry paintbrush or a small cleaning brush (like a bottle brush but smaller) to dust it. A can of compressed air is also good for blowing off dust.
What to do with your old air cooler
Reduce and reuse are always better than recycle. Repair is too. So if your old air cooler still works, try to find it a good home on a local swap site or street WhatsApp – they work better than the front wall, where it might get rained on. If it’s not working, you could take it to a local repair cafe. And if it’s beyond repair, check your council website or check Recycle Your Electricals: electricals don’t belong in general waste.
Searching for a fan that will keep you cool on the move? Read our guide to the best handheld fans
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Caramel Quin is a journalist specialising in consumer technology. She prides herself on real-world testing and plain English. Her pet hates are jargon, pointless products and overcomplicated instruction manuals. Caramel is an engineering graduate who has won awards for communicating hi-tech subjects to normal people. When she’s not testing gadgets, she’s feeding pets (16 beasts at the time of writing) or pottering at the allotment
• This article was originally published on 13 August 2025. Reviews published in the Filter may be periodically updated to reflect new products and at the editor’s discretion. The date of an article’s most recent update can be found in the timestamp at the top of the page. This article was amended on 14 July 2026; the Morphy Richards Flexi Freeze was added after testing, five coolers were removed, more information was added to the buying guide, and prices were updated throughout.