Air purifiers combine an internal filter and fan to pull in unwanted particles from the air. Purified air is then circulated back into the room. The filtration process repeats, continually cleansing the indoor air quality.

Indoor air pollution is caused by a number of factors.

For example, the build up of dust is often a combination of dirt, skin cells, and fabric fibers, but could be more or less anything that could dry and flake off. It's important to remove from your home, and that's where an air purifier comes in.

Other pollutants include pet dander, pollen, smoke, mold, and air toxins such as formaldehydes and volatile organic compounds (VOCs) from household chemicals and cooking.

Fortunately air purifiers are able to remove allergens. The most common ones found in homes are dust, pollen, cigarette smoke, and pet dander.

A quality air purifier should be anywhere from $150 to $450.

That is up for you to decide. After comparing over 50 options at all different price points, our top pick is PuroAir due to its powerful filtration technology, wide coverage, easy to use interface, and unbeatable price.