Air cleaners are a great way to address specific air quality issues. Media air cleaners remove 80% of household dirt and dust. Electronic air cleaners are designed to address allergens and smoke. The "grand daddy" of all air cleaners is the patented American Standard AccuClean. This relatively new filter system can clean up to 99.98% of allergens from the air (dust, pollen, pet hair and dander, dust mites, mildew, lint, fungus, most tobacco smoke, cooking grease, even bacteria). It can trap allergens down to .3 microns (about 12,000 of them can fit in the period at the end of this sentence). The "filters" in this system are cleanable which makes it more cost effective over time. www.americanstandardair.com , www.yourhome.honewell.com.