The AustinAir Healthmate Plus has the highest levels of HEPA and carbon/zeolite filtration. The "Plus" is enhanced to add an additional layer of filtration against volatile organic chemicals. It is whisper quiet, cleans 1500 sq. ft., and is effective even for allergies/chemical sensitivities. It weighs 45 pounds, and has a 5 year filter with pro-rated warranty. Top unit in the Austin Air line! Austin Air Healthmate Plus Air Cleaner