Highly efficient electrostatic filtering material attracts dust and pollen like a magnet. Captures microscopic airborne dust, pollen, mold spores, pet dander, bacterial and the particles that carry virus. a merv 1 rating requires a 65% to 80% efficiency on 1-3 micron particles and greater than 85% efficiency 3-10 micron particles, when tested in accordance with ashrae test standard 52. 2 bright star cooler meets and exceeds these requirements