If you buy one, it’s important to get an air purifier that’s appropriate for the size of the room you want to use it in. Rooms reeking of smoke, alarms going off due to the visible haze inside your home, waking up in the middle of the night smelling smoke in the air. Australia’s bushfire crisis is affecting air quality and the wellbeing of many of us. Smoke haze has been blanketing many parts of the country, including some of our major population centres – Canberra, Sydney, Melbourne and other capitals. Experts agree we need to stay inside and out of the smoke as much as possible, especially when the air quality is hazardous. “The guidance that’s being provided of staying indoors with your doors and windows closed is good up to a point,” says environmental scientist Amanda Wheeler, of the Australian Catholic University, who has conducted research evaluating interventions to improve indoor air quality affected by smoke. “Houses naturally breathe, because you don’t want to build up carbon monoxide inside a house until the point that you’re going to keel over.” How good that advice is depends on how airtight or leak...