In an independent test, twenty-one of the top brand name air cleaners were tested and rated by one of America's leading consumer reporting organizations. After careful review it was determined that Austin was rated as follows: Best overall air cleaner for combined dust, smoke, gas and odor removal Best filter Best HEPA filter Best gas and odor removal Best warranty Best guarantee SUPER QUIET OPERATION! On Its Lowest Setting You Will Not Know Its Running! 5 Year Filter Life/Warranty - No Expensive Replacement Filter To buy Every Few Months!