Honeywell Home 21.5" x 27.5" Media Air Filter

New MERV 11 (at 492 FPM) performance with lower pressure drop at no additional cost. Product Features Efficiency ratings are based on American Society of Heating, Refrigerating and Air-Conditioning Engineers Standard 52.2 1999. Efficiency ranges are defined for small particles, E1=0.3 to 1.0 microns; medium particles, E2=1.0 to 3.0 microns; and large particles, E3=3.0 to 10.0 microns. Product Specifications Application: Replacement Filter Efficiency Standard: Efficiency ratings are based on American Society of Heating, Refrigerating and Air-Conditioning Engineers Standard 52.2-1999. Efficiency Standard: Efficiency ranges are defined for small particles, E1=0.3 to 1.0 microns; medium particles, E2=1.0 to 3.0 microns; and large particles, E3=3.0 to 10.0 microns. Fractional Efficiency: E1=25%, E2=62%, E3=85% Minimum Efficiency Reporting Value (Media Filters Only): MERV 11 Static Pressure Drop (in. w.c.): 0.23 at 500 FPM used with: Honeywell F27F10570