Koch Pleated Air Filters by the Case | MERV 8, 11 & 13

Koch Filter Multi-Pleat air filters for furnaces, heat pumps, air handlers and commercial HVAC systems, sold by the full case. We stock more than 150 Koch filters in 1", 2", 4" and 5" depths, from common sizes like 16x20x1 and 20x25x1 to hard-to-find and custom sizes. Every listing shows the Koch part number, the actual filter dimensions and the case quantity.

Shop by MERV Rating

MERV 8: Multi-Pleat XL8
The everyday standard for homes and light commercial systems. 100% mechanical media with low airflow resistance.

MERV 11: Multi-Pleat XL11
A step up that adds finer dust and pet dander, with only a modest increase in resistance.

MERV 13: Multi-Pleat Green13
Koch's high-efficiency pleated filter for hospitals, labs, offices and homes that want the highest efficiency their system can handle.

Replacing media in a Trion Air Bear air cleaner? Koch's Series AB filters are available in MERV 8 and MERV 11.

Finding Your Size

Air filters are sold by nominal size, the rounded size printed on the frame of your current filter. The actual filter is about 1/2" smaller so it slides into the slot. Match the size printed on your old filter rather than measuring the opening. Can't find it, or need an odd size? Send us a photo of your current filter and we'll match it.

How Many Do I Need?

1" and 2" filters come 12 to a case, 4" filters 6 to a case, and 5" media filters 3 to a case. Check 1" and 2" filters monthly and replace them at least every three months. Deeper 4" and 5" filters typically last 6–12 months. A 12-pack covers three years of quarterly changes for one system, or a full year for three.

For Facilities and Contractors

Koch part numbers are listed on every product so you can match your specs exactly. We offer bulk and recurring orders through our wholesale program and tax-exempt purchasing. Most in-stock orders ship within 1 business day, and special-order sizes are ordered direct from Koch.