Do I really need air conditioning in the UK? The best portable aircon tested – plus the pros, cons and alternatives

As hotter summers become the norm, home aircon can feel increasingly tempting. We put six units to the test for cooling power, noise and energy use – and explain what you need to know before buying • How to sleep in a heatwave • Can air conditioning be green? Tell people you’re testing air conditioning, and the truth soon comes out: far more people have aircon than you’d ever imagine. It’s a guilty secret, the home improvement equivalent of Botox or weight loss jabs – everyone notices the results, but nobody admits to the method. Most portable aircons are in bedrooms, hidden away from visitors, so they’re easy to keep secret. And while friends with aircon don’t suddenly look younger or slimmer, they do look suspiciously well rested during a heatwave, while you’ve spent the night tossing and turning. So if you’re using an aircon unit, why have it in the bedroom? Warm air rises, so upstairs bedrooms can be the hottest by the end of the day, making for restless nights. And if your bedroom is in a loft conversion, it’s even worse: the roof absorbs the sun’s heat all day before radiating it back into the room after dark...