Air cleaners and purifiers can filter the air your family breathes by removing particles such as dust, pet allergens, odors and smoke from your home. The air that is returned to the room is much cleaner. Air cleaners are available in portable units or whole-home systems. There are many on the market with various filtration stages and some have enhanced air quality features, so prices vary considerably. Before you start shopping, these tips can help you sort through the air cleaner features.