When the temperature rises, an air conditioning unit is a summer dream come true. While fans just circulate already-warm air, these appliances remove the hot, humid air from a room and blast a deliciously icy breeze around instead. This is ideal in a stuffy office, if you just can’t sleep when the nights turn balmy or if you have a conservatory where intense heat builds easily.
However, most people don’t want to go to the hassle or expense of installing a permanent wall-mounted unit that may only be used a few weeks of the year. Instead, portable air conditioners (PAC) can be moved between rooms and stored away during winter. Be aware that to function properly as an air conditioner, they must be vented via a duct through a window or wall.
Though some models come with window kits to make this easy, these generally only work with sliding or sash windows so unless you’re especially DIY-savvy, your window will be wide open whenever you use the air conditioner, making it work harder. The units are all fairly large and heavy, so be sure there is room to use it next to a window and remember that if it doesn’t have a pipe, it’s really an evaporative air cooler and not an air conditioning unit at all.
Don’t expect any of these appliances to be cheap. Prices start at around £250 and the more powerful the machine, the more expensive it will be. Cooling requirements are measured in British thermal units (BTU) and the higher the rating, the larger the space the air conditioner will cool.
A unit with 7000 BTUs will cool a small room of around 18 to 20 square metres, but always check the size of the room before you buy as a unit with too low a BTU for the space won’t cool it effectively. Other features to look for include a remote control, programmable timer and a sleep mode so it can cool quietly through the night.
How we tested
We tested a range of portable air conditioner units in our own home over especially hot days back in June and July to find the best, taking into account the price, portability, cost and how well they cooled us down despite baking temperatures outside. Note that with such high demand for conditioners during last month’s heatwave, some of these are currently out of stock but will be available again soon.
The best portable air conditioner units for 2021 are:
- Best overall – MeacoCool MC series 7000: £279.99, Amazon.co.uk
- Best for sleeping – DeLonghi pinguino PAC EX120 silent: £700, Amazon.co.uk
- Best lightweight model – Draper 56124 mobile air conditioner: £279, Amazon.co.uk
- Best for every window – GoodHome takoma mobile air conditioner: £269.99, Screwfix.com
- Best for year-round use – Tower presto 9000BTU air conditioner, £299.99, Robertdyas.co.uk
MeacoCool MC series 7000
- BTU: 7000
- Dimensions: 70.1 x 35 x 34.8 cm
- Speed settings: 2
This ticked every box for a portable air conditioning unit that was easy to use around the home, (relatively) unobtrusive, and possible to store away when not in use, all for a reasonable price.
It’s not suitable for huge spaces as it only has a BTU rating of 7,000 but should work in rooms between 12-22 metres-squared. This was more than enough in our bedrooms and living room where we needed it the most and the lower BTU meant it was also smaller and lighter than many units we tested, weighing in at a mere 20.5kgs and standing only 70cm tall. This meant we could easily move it between rooms if needed. It also had one of the longest ducts of all the appliances so we had a little more flexibility with where we positioned it.
Best of all, it comes with both a standard window kit and a flexible kit which – rejoice! – works on any window and makes a huge difference to cooling. It has a 24-hour timer, sleep mode and remote control, and uses the new R290 refrigerant which is kinder to the environment. An all-round heatwave hero.
DeLonghi pinguino PAC EX120 silent
Best: For sleeping
- BTU: 11500
- Dimensions: 39 x 44.5 x 80.5 cm
- Speed settings: 3
Air conditioning units are never going to be a thing of beauty but this DeLonghi model was by far the best looking we tested, with a matt black surface, matching black remote and glossy digital screen. It’s very easy to work with so you can tweak the temperature or fan speed from the remote, or even programme the timer without budging from the sofa. It lowered the temperature in our kitchen in no time, thanks to its high BTU rating, and because the hose was slimmer than other models we didn’t need to open our windows quite as widely. It has a dehumidifier function, a timer and a useful light to indicate if conditions are uncomfortable, acceptable or optimal.
Best of all, it was much quieter than most units, albeit not quite silent as the name suggests. It operates with a decibel range between 49 and 53 and we soon stopped really noticing it working in the corner at all. It would be a great addition to a home office or child’s bedroom as a result, though it can also cool much larger rooms of up to 110 metres-cubed.
Draper 56124 mobile air conditioner
Best: Lightweight model
- BTU: 9000
- Dimensions: 37.5 x 32 x 88 cm
There’s no such thing as a featherweight air conditioner but this was one of the lightest models we tested, at just 21.7kg, so we didn’t need an army of people to lift it upstairs to cool a bedroom. It also has castors and is slimmer than most other units so it was easy to wheel around downstairs as needed.
It was up and working in moments, though we had to hold the hose on the back of the appliance while extending it towards the window as it kept popping off. There is no compatible window kit either so you do need to open the window fairly wide to fit the hose out. We were surprised to discover the unit still managed to cool the room fairly quickly despite battling the warm air outside though, and it reached a pleasant temperature in no time. It’s not too noisy, and has a 24-hour programme timer, automatic diagnostics function and remote control. It’s a great choice if you plan to store it away over winter once the weather turns.
GoodHome takoma mobile air conditioner
Best: For every window
- BTU: 9000
- Speed settings: Variable-speed
This well-priced air conditioning unit wasn’t too heavy at 31kg and comes on castors so it can be easily moved between rooms without too much hassle. It has cooling, dehumidification and ventilation functions and we were impressed how quickly it made our living room icy, with a cooling effect felt almost immediately. It comes with an easy-to-operate remote control and has a timer and night mode so it won’t disturb your sleep. On its other settings, it is a little on the noisy side so you might need to turn the TV up if you’re watching in the same room.
Our only gripe? We would’ve liked the pipe to be a little longer as we had to keep it very close to our window for venting. On the plus side, it’s compatible with an ingenious fabric window kit (£11.99, Screwfix.com) that can be bought separately to make this model work with almost any window.
Tower presto 9000BTU air conditioner
Best: For year-round use
- BTU: 9000
- Dimensions: 33 x 34 x 68 cm
- Speed settings: 2
Packing away a heavy air conditioner unit for the winter is a real pain. This versatile machine can also be used as a fan and dehumidifier so when the temperature dips, it will prevent dampness in your home. It was one of the better looking machines we tested too, with curved edges and an LED touch-screen so it won’t look too ugly sitting in the corner for longer periods.
When set to cooling, there are two speed settings which are also useful when you prefer the machine to be a little less noisy. The fan works very well at directing the cool air throughout the room rather than focusing on one area and the temperature is adjustable between 15-31C, a slightly wider range than some of the other units. It has a 24-hour timer for efficient operation, overheat protection and a self-evaporating system, though we found we did have to empty collected water manually when we used it for a long time. Despite this, it’s a good buy you can use year-round.
Portable air conditioners FAQs
How much does a portable air conditioner cost?
Portable air conditioners can cost anywhere between £250 to more than £1,000, depending on the product’s BTU rating. While fans are considerably cheaper, portable conditioners are worth investing in so you can cool down a larger space.
Cheaper models with a lower BTU rating tend to be below the £500 mark and generally aren’t worth buying unless you want to to condition a small room. Higher BTU models are bigger, pricer and can cool a larger space.
What type of air conditioner should I buy?
The type of air conditioner you buy depends on the size of the room you want to cool. Portable conditioners with a BTU of 9,000 or 12,000 can cool a room of around 21-30 square metres respectively while anything below this will only cool smaller spaces. Experts recommend multiplying the dimensions of your room by five to find your necessary BTU.
You might also want to consider noise; if this is a concern, go for a model with sleep mode which automatically switches the conditioner off once the room is the right temperature.
Do I need a drain for a portable air conditioner?
Fully self-evaporative models automatically evaporate moisture out of the exhaust hose along with warm air, while older manual removal need you to drain the collected moisture manually to enjoy a continued cooling effect.
How often do you have to empty a portable air conditioner?
While some conditioners are self-evaporating and don’t require manual removal of condensate water, standard portable conditioners have buckets that need to be emptied periodically – anywhere between eight hours or up to a month, depending on the model. Even some self-evaporating models might need emptying after long-time use.
The verdict: Portable air conditioners
The MeacoCool MC series 7000 was definitely the easiest air con unit to use at home thanks to its longer hose, smaller size and clever flexible window kit. Unless you’re cooling a huge area, it’s a no-brainer. For slightly bigger rooms, look at the Tower presto 9000BTU air conditioner which does the job well without looking ugly standing in the corner.
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