The ceiling height in a normal room is 2-3 metres (7-10 feet). Assuming the height is 3m/10ft, Rensair’s airflow capacity means it is able to clean all air in a 185m²/2,000ft² room once every hour. If you are running the Rensair air purifier at lowest capacity, we advise that you use one Rensair for every 120m²/1,250ft² of space. For larger spaces, multiple Rensair air purifiers can be used in combination.