What is the best air purifier online stores have to offer? It really depends on what you are looking for, and there are quite a few options. Most depend on electrostatic cling, and prices and efficiency do vary quite a bit. Most are only suitable for clearing the air in a single room, but otherwise are very energy efficient. They do not suck air and move it through pipes but only gently circulate the air and do their job over hours and days.
Visit a website that shows you all the options. A tower air purifier might cost a few hundred dollars, but can efficiently remove particles from a heavily trafficked room such as a living room with a front door. Hallway purifier can be mounted on a wall, and quietly remove contaminants in a gradual yet effective manner. Some are efficient enough to work with batteries only.