Can I improve my indoor air quality by simply using an air filtration device?

Well, filtration can be combined with a ventilation system to remove airborne pollutants such as mold spores and pollen from the incoming air. Or, it can be combined with a forced-air heating/cooling system to filter out pollutants released by low-tox interior materials into the recirculated air (e.g. lint from cotton upholstery or drapery materials). To depend on filtration to do everything—without using the principles of eliminate, separate and ventilate—is difficult to do. Such a system will need to be very effective and very powerful; meaning costly-to-install, expensive-to-operate, and noisy. While affordable, room-sized filters are available, they are just that—room sized. They aren't designed to handle more than an average-sized room with the door closed. And even these work much better if you've implemented the other principles first. The bottom line is this: Filtration is most effective at removing the pollutants that remain after you've implemented the other three principles.