Honeywell 17400 Enviracare QuietCare HEPA Air Cleaner Ultra quiet air cleaner is up to 30 percent quieter than air cleaners with similar performance. HoneywellEnvirocare is the number one brand recommended by physicians for air cleaning. True HEPA filter captures 99.97 percent of airborne particles as small as .3 microns, including pollen, pet dander, smoke, mold spores, dust and more. Quality Surround Seal HEPA filter technology funnels incoming air precisely through the HEPA filter. Activated carbon pre-filter helps reduce household odors.