The Tier1 20x20x4 furnace air filter has actual dimensions of 19.5" x 19.5" x 3.75" (nominal size 20x20x4) and carries a MERV 13 rating. This MERV 13 performance captures particles as small as 0.3 microns, including pollen, dust mites, pet dander, mold spores, smoke, bacteria, and virus carriers, making it ideal for households with allergy sufferers or those seeking superior indoor air quality.

Tier1 recommends replacing this 4-inch deep-pleated furnace filter every 3 to 6 months, depending on your home's air quality, pet presence, and HVAC usage. Because of its extended pleated surface area, this filter typically lasts up to 3 times longer than a standard 1-inch filter, providing longer service intervals without sacrificing airflow.

This Tier1 20x20x4x4 filter is designed as a universal replacement compatible with most major HVAC brands that use a 4-inch media cabinet, including Honeywell, Aprilaire (5-inch cabinets may require adapter), Carrier, Lennox, Trane, and Bryant systems that accept a 20x20x4 media filter. Always verify your existing filter's actual dimensions before ordering to ensure proper fitment.

The Tier1 MERV 13 20x20x4 furnace filter captures a broad range of airborne particulates, including dust, pollen, mold spores, pet dander, lint, smoke, smog, bacteria, and fine respiratory droplets. Its electrostatically charged synthetic media provides high particle capture efficiency while maintaining low resistance to airflow, helping protect your HVAC equipment and improving indoor air quality.

No. The deep 4-inch pleated design of this Tier1 filter provides significantly more surface area than a 1-inch filter, allowing it to achieve MERV 13 filtration without restricting airflow. This reduces strain on your blower motor, improves HVAC efficiency, and helps lower energy costs. For best performance, replace the filter before it becomes visibly loaded with debris.