A little education is highly recommended when not sure what size air purifier to choose. Air purifiers represent a good solution for both sensitive and healthy individuals. They are mandatory for people suffering from chronic respiratory conditions too. All in all, you have to think about the size of a room. If you want a portable unit to move around your home, make sure that it can match the largest room. The specifications should include the maximum size a purifier can handle. Make sure that it is slightly more potent than what you actually need, only to ensure a higher efficiency.