Air purifiers generally use HEPA filters, a fibre mesh that captures any small particles daring to float by. The Aaira combines one of these with a carbon filter (to neutralise noxious odours) and an HOCI generator, which uses a scoop of table salt dissolved in tap water to produce a weak acid (think along the lines of lemon juice), which in turn zaps a range of bacteria and viruses that might be lingering. This top-of-the-range model stands around waist-high, but quietly deals with rooms measuring up to 43sq m. It’s WiFi-enabled, so you can ask Alexa or Google Assistant to turn it on and off, or up and down, while a dedicated app gives you control over timers, schedules and more wherever you are.
