India, Nov. 2 -- Would you spend money on an air purifier for a room where you spend nearly eight hours every night? It is a pretty reasonable question, particularly when outdoor pollution, dust and other airborne particles can affect indoor air quality too. Keeping the windows shut is not always a complete solution and ordinary fans cannot remove fine particles from the air. A bedroom air purifier can help reduce certain airborne pollutants, but not every model is suitable for a sleeping space. A machine that is too noisy, has limited coverage or needs expensive replacement filters could quickly become an inconvenience. Before buying one, here are the features worth checking, along with a few things that should not influence your decisio...