It's generally recommended to close doors and windows in the room that you're trying to keep cool, so if you only want to keep a small bedroom cool then you can opt for a cheaper lower BTU unit, however an open plan space will require a much more powerful appliance with a larger BTU. Portability

Beyond that, this air con unit is bulky and heavy. It weighs in at 31.5kg, one of the heaviest units we've tested, so carrying it upstairs is a definite two (strong) person job. But, it looks good. And its curved front, minimal design, and gloss finish all make it far more unobtrusive in a room than you might expect. The build quality is also solid and robust. This has the effect of dramatically reducing the temperature in the room. In our tests, we found the best portable air conditioners, used in a well-sealed room, could reduce the temperature by up to 10 degrees in under an hour. The next step after looking at products in the same category, was to look at products from the same brand, Challenge. Most portable air con units come with an energy rating stated on their energy label to help you compare how many kW per hour the unit will use. How we test portable air conditioners Similarly, investing in a unit with a timer function gives you the ability to programme the unit to turn off a few hours after you've got into bed, or to turn on during the hottest part of the day to keep the house cool for pets, or reduce the temperature before you get home from work. A unit with Smart functionality can also offer the means to control the unit when you're away from home. Window kitThe Russell Hobbs RHPAC11001 can do just that, offering 4-in-1 use thanks to air con, fan, dehumidifier, and heater functionality. Depending on your needs that could mean it offers better value for money, as it will be useful all year round, keeping your space cool in the summer as well as warm in the winter. It also comes with a remote control and two window kits included, a timer function, 'night' mode for (slightly) quieter night-time operation, plus 3-in-1 air con, fan and dehumidifier functionality. So whilst the best fans definitely work to cool a person thanks to the breeze they create that does a surprisingly good job of cooling the skin, only an air conditioner can dramatically lower the temperature of an entire room or living space. And only an air conditioner will deliver that fridge-like cold air we all crave in a heatwave. Do portable air conditioners cost a lot to run? It also offers some good functionality, including air con, heater, and dehumidify functions that enable year-round use, plus a timer, 'night' mode, remote control, and WiFi connectivity. The first thing you'll want to consider when choosing the best portable air conditioner for your home is BTU.

Overall, if you're looking to invest in a powerful air conditioner that can bring an icy to chill to a room in under 20 minutes, or your willing to pay a little more for white noise over the thundering din of most air con units, the AEG Comfort 6000 Portable Air Conditioner is a great buy. Sadly it doesn't come with a window kit included, or a remote control – but WiFIi connectivity means you can control it from your phone instead, a really handy feature. Like most portable air con units of this power, it isn't light, weighing in at 27kgs, and its most common negative gripe from users is – as with most air con units – its noise. On its lowest, night-time setting the manufacturer advises it produces 53dB of noise. Interestingly, figures aren't given for decibel levels on the highest fan speeds, suggesting they climb quite a lot higher as you scroll upwards through its two additional speed settings. A remote control is always a handy feature to have, especially if you're using the unit in the bedroom and don't want to have to get out of bed to adjust settings or turn the unit off.

Compare Similar Products to Challenge 6 Litre Portable Air Cooler - White

TIMER, NIGHTLIGHT & NEGATIVE ION AIR PURIFIER; You can set the unit to operate continuous or 1 - 12 hours according to your needs. Handy nightlight switch for an undisturbed sleep. Turn on the negative ion function to release large quantity of anions which help in the removal of airborne pollutants as small as .01 micron such as allergens, pollen, mold, smoke, pet dander, unpleasant odors, dust, and other airborne irritants. However, a higher BTU also means a higher price tag, and likely higher running costs, so it's a balancing act of investing as much as you can for better performance against how much you're willing to pay upfront for a unit. Room size

Find out why Challenge 6 Litre Portable Air Cooler scored an incredible review score of 9.2 out of 10. Relatively affordable, lightweight and compact, energy efficient and easy to use, there's a lot to love about the MeacoCool MS Series portable air conditioners. Which is why we think they're the best portable air conditioner to invest in if you're looking for an affordable all-rounder. After being massively impressed by the brand's virtually silent Duux Whisper Flex Ultimate Fan, we had high hopes this unit was going to be just as whisper-quiet, but sadly that also wasn't to be, with the North Smart proving just as loud as your average portable air con. Personally, we'd sacrifice some chill (and save a lot of cash) and opt for the Duux Whisper Flex Ultimate Fan over the North Smart every time. Especially if you're looking for ways to keep a bedroom cool as the fan's silent operation won't disturb your sleep. Whilst the fan won't actively lower the room temperature like the North Smart can, all those who've tested the Duux Whisper Fan now swear by it's oh-so-silent 'natural-feeling' breeze, reaching for it as a go-to sleep aid whenever the mercury soars.

Wilko Beldray 6 Litre Air Cooler

You might also want to consider whether you want your portable air conditioner to come with a timer, remote control, or WiFi connectivity. You're likely opting for a portable air con unit because you would like it to be... portable! However, in reality, even the best portable air conditioners are both bulky and heavy, weighing from 20kgs for a smaller 'lightweight' air conditioner to 30kgs+ for more powerful units.

You also get a lot of extras with the Pro Breeze 9000 BTU 4-in-1 Portable Air Conditioner considering its price tag, including a remote control, timer, 'night' settings, and WiFi connectivity. Although some reviewers mention its Smart features leave a little to be desired. Very often an air con unit will come with additional functionality, usually a fan setting and dehumidifier function. More expensive portable air conditioners sometimes also feature a heater function that means you're more likely to be able to get year-round use out of your investment. The brand of product you buy can vary in importance, from person to person. Some people will of course be much more particular about the brands they will use. Whilst others aren’t interested in the brand and are more interested in the overall quality or price of the product itself. Thankfully Challenge is a brand that many customers have grown to love over the years and is very popular for items in the Air conditioning category. A powerful portable air conditioner that looks good, is easy to use, is relatively quiet in comparison to most, has WiFi connectivity, and – most importantly – can cool down a room fast, as long as you don't mind its slightly higher running costs. In terms of cooling powers this is one of the most powerful portable air con units we've tested, but, that power does comes at a price, with the AEG Comfort 6000 using 3400W of energy compared to the MeacoCool MC Series 7000BTU units 780W. It means running costs for the AEG are higher – as is the initial outlay compared to the Meaco – but, our reviewer did find they didn't need this unit running for as long to cool down a space.There's no denying portable air con units are expensive, so if affordability is key then this Pro Breeze 9000 BTU 4-in-1 Portable Air Conditioner is certainly a winner on price. We found the the best bet is to run the air con unit in a bedroom for a few hours before you want to go to sleep, and then turn it off once you turn in for the night. In our tests, similar to the MeacoCool MC Series 7000BTU Portable Air Conditioner and AEG Comfort, it managed to cool a 4.5m2 room by 2°C in 10 minutes, and despite the manufacturer stating its noise level is 65dB, our reviewer found it much quieter than the Meaco model, comparing it to the AEG Comfort on this front. All in all, the MeacoCool MC Series 7000BTU Portable Air Conditioner is a good all-rounder at an affordable price point.