Air Defense HD 20x25x4


Air Defense Mechanical MERV 8A has tested to have longevity and strong media with an efficient design to its construction. From the pleat consistency, durability, and the comparison to other high capacity MERV 8 filters, the Air Defense Mechanical MERV 8A stands alone as the new standard.

***Actual Size*** 19 1/2" x 24 1/2" x 3 5/8"


  • 100% synthetic, proprietary media resists moisture and damage 

  • Mechanical efficiency – achieves MERV 8A rating before and after a conditioning step

  • Independently tested and verified for quality control

  • Extremely low-pressure drop and high dust holding capacity


  • Heavy-duty, moisture resistant beverage board frame

  • A two-piece frame provides rigidity with double-wall thickness around the outer edge 

  • The die-cut pattern provides 50% more contact points between the media pack and frame 

  • Integral die-cut cross members provide strength and rigidity   

  • A water repellent adhesive used to bond the frame with the media pack 

  • Rust-resistant expanded metal support grid made of galvanized steel

  • 100% water repellent, high-strength adhesive coats the entire interior of the frame

    The Air Defense HD 20x25x4 is far and away, one of our most popular items. People can't seem to get enough of it.

    Inventory Last Updated: Jul 18, 2024