Seems apt that with the haze situation reaching a peak here in Singapore (PSI 400, what?!!) we should start thinking about air purifiers. Most aircons come equipped with air purifiers (please check that yours does as well) and I have mine switched on all the time these days.
But, nothing is as powerful as an air purifier unit. Seeing how this haze comes around once a year, we might want to invest in one. It comes in handy if you live near a highway, have neighbors that are renovating or just aimed at the kitchen all the time to eliminate food odors.
Smaller USB units seem to be popular as most of us are near the computer all day.