Filter King AF21x21x1-M11 Merv 11 Air Filter 21x21x1

Product Description

The FILTER KING AF21x21x1-M11 is a MERV 11 pleated air filter designed for residential and light commercial HVAC systems. With a nominal size of 21x21x1 inches and an actual size of 20.5 x 20.5 x 0.75 inches, this filter fits standard 1-inch filter slots without modification. MERV 11 filtration captures a broad range of airborne particulates including dust, pollen, mold spores, and fine particles generated by household activity. HVAC technicians and service pros use MERV 11 filters when a customer needs better-than-standard air quality without the static pressure penalty of higher-rated filtration.

This filter is suited for forced-air residential systems and light commercial air handlers where 1-inch filter housings are standard. It fits return air grilles, media cabinets configured for 1-inch media, and air handler filter racks accepting a 21x21 nominal size. Typical applications include residential furnaces, split-system air handlers, and packaged rooftop units with standard 1-inch filter tracks. Sold in quantities of 10, this filter is well suited for bulk replacement on multi-unit properties or routine seasonal maintenance schedules.

Key Features

• MERV 11 rated — captures dust, pollen, mold spores, and fine particulate matter
• Pleated media construction increases surface area for improved particulate capture
• Nominal size 21x21x1 inches fits standard 1-inch residential and light commercial filter slots
• Actual dimensions 20.5 x 20.5 x 0.75 inches for proper fit without binding
• Sold in packs of 10 for efficient bulk replacement

Compatibility

Designed as a standard 1-inch MERV 11 replacement filter for residential forced-air furnaces, split-system air handlers, and light commercial packaged units accepting a 21x21x1 nominal filter size.

Installation Notes

Installation should be performed by a qualified HVAC technician or knowledgeable service professional. Power down the air handler or furnace at the disconnect before removing the used filter. Confirm airflow direction arrows on the filter frame align with the direction of airflow through the system before seating the filter. Replace filters on a regular maintenance interval appropriate to the site conditions and system runtime.