Hong Kong start-up Aurabeat’s lab-tested purifier rids the air of 99.9 per cent of Covid-19 viruses. Is it enough for the real world?

• A stand-alone unit retails for HK$4,980 (US$642), while a portable model more suitable for personal space, such as a car’s interior, is priced at HK$1,280
• Consumer Reports recommended purifiers with a clean air delivery rate (CADR) of over 240 cubic feet per minute (cfm), which gives roughly five air exchanges per hour. Aurabeat’s stand-alone product has a CADR of 221 cfm, according to the company