Merv 13 Pleated Air Filter - 18 3/8" x 21 1/4" x 2" Quantity:12-pack the greater it's resistance to

the greater it's resistance to airflow

oxidation and deterioration

The filtering media consists of two layers of Stainless Steel roll formed baffles

some just refer to them as electrostatic filters

One way to overcome this problem is to increase the surface area of the filter media

Merv 13 Pleated Air Filter - 18 3/8" x 21 1/4" x 2" Quantity:12-pack the greater it's resistance toAny Kind of Filter's Extended Surface Pleated Filters outperform ordinary furnace filters with medium efficiency and are designed for lower pressure drop, and long service life which reduces HVAC equipment maintenance and energy costs. A higher MERV rating means that the air filter that you are about to purchase possesses a higher amount impurity filtration ability than your ordinary filter.