Practical Pleated Air Filter (2-Pack) - 18" x 21" x 5" Quantity:Default and the greater the pressure

and the greater the pressure drop it creates

than standard fiberglass filters purchased at retail outlets

åÊWe look forward to delivering our American-made

if not you can measure it or check the HVAC unit and the owner‰۪s manual

degrade and restrict air flow

Practical Pleated Air Filter (2-Pack) - 18" x 21" x 5" Quantity:Default and the greater the pressureYes, we even have the odd sizes! The "Practical Pleat" media is up to 28 times more effective at capturing particles than standard fiberglass panel filters. In general, the more efficient a filter is at removing particles, the greater it's resistance to airflow, and the greater the pressure drop it creates. One way to overcome this problem is to increase the surface area of the filter media. The "Practical Pleat" contains over 500% greater surface