This filtration system is the most highly recommended and most often used system. It effectively captures 40% of particles at 1.0 micron and larger, which is 11-times the efficiency of standard pleated filters. This filter also resists moisture found in air conditioning systems, and does not support microbial growth on the pleats.
(For 14"x14"x4" return air filter grilles ONLY - NOT for Media Air Cleaners. Can ONLY be used on 14"x14"x4" filter grilles.)
(We recommend a 4" filter change at least 2 times per year - September & March. For DIRTY environments or most efficient filtration, you may need to change filters more often...do monthly visual checks for the first few months.)