Verdict Keenly priced, the Vonhaus 12000 BTU High Performance Air Conditioner is suitable for rooms up to 35m2 and it even comes with smart controls, offering remote control via the Smart Life app. It can cool quickly in the right conditions, but it does need its water tank to be manually emptied when the light goes on (not too frequently), and it’s a little loud. Still, if you’re on a tight budget, this is a great option.