Koch Filter P421820 Pleated Air Filter 18x20x2

Product Description

The KOCH FILTER P421820 is a 2-inch pleated air filter measuring 18 x 20 x 2 inches, built for residential and light commercial HVAC systems that require deeper filtration than standard 1-inch media. The pleated design increases media surface area compared to flat-panel filters, supporting improved particle capture across a range of airborne contaminants while helping maintain balanced system airflow. Licensed HVAC technicians and qualified service professionals install this filter as part of routine preventive maintenance or scheduled filter change-outs.

This filter is suited for forced-air heating and cooling systems where a 2-inch filter slot is present in the air handler, furnace cabinet, or return-air grille. The 18 x 20 x 2-inch nominal size fits common residential air handler configurations. It is appropriate for systems requiring periodic filter replacement to sustain acceptable indoor air quality and protect blower components from dust accumulation.

Key Features

• Nominal dimensions of 18 x 20 x 2 inches fit standard 2-inch filter tracks and return-air grilles
• Pleated media design increases surface area for improved particle capture compared to flat-panel filters
• 2-inch depth provides extended filter life between change-outs relative to 1-inch media
• Supports balanced airflow while capturing airborne dust, pollen, and particulates
• Designed for forced-air HVAC applications in residential and light commercial settings

Compatibility

Designed as an OEM-style replacement pleated air filter for forced-air HVAC systems requiring a nominal 18 x 20 x 2-inch filter.

Installation Notes

Installation is performed by a licensed HVAC technician or qualified service professional. Power down the air handler or furnace at the disconnect or thermostat before opening the filter cabinet. Note the airflow direction arrow printed on the filter frame and orient the filter so the arrow points toward the blower. Replace filters at manufacturer-recommended intervals or when visual inspection shows heavy dust loading to prevent restricted airflow and blower strain.

Technical Specifications

• Filter Type: Pleated Air Filter
• Nominal Length: 20 inches
• Nominal Width: 18 inches
• Nominal Depth: 2 inches

Standard Information

• Brand: KOCH FILTER
• Manufacturer Part Number: P421820