The Filtrete Micro Allergen 17.5x23.5x1 air filter has actual dimensions of 17.4 x 23.4 x 0.81 inches and carries a Filtrete MPR (Microparticle Performance Rating) of 800, which is equivalent to a MERV 11 rating. This electrostatically charged filter is engineered by 3M to capture microscopic particles like pollen, pet dander, mold spores, dust, and smoke from cooking and fireplaces, making it ideal for households with allergy sufferers.

3M recommends replacing the Filtrete Micro Allergen 17.5x23.5x1 filter every 3 months under normal household conditions. However, homes with pets, smokers, or residents with allergies may need to replace it every 45-60 days. The filter features 3M's Filter Life Indicator technology on the packaging to help you track replacement timing, ensuring peak HVAC performance and indoor air quality.

The Filtrete Micro 17.5x23.5x1 uses 3M's exclusive electrostatic technology to attract and capture large airborne particles such as household dust, lint, and pollen, as well as microscopic allergens like pet dander, mold spores, smoke, and smog particles. The MPR 800 rating means it captures up to 90% of large airborne particles from the air that passes through the filter, providing 25% better filtration than standard fiberglass filters.

No, the Filtrete Micro MPR 800 is specifically engineered with 3M's pleated design to maintain optimal airflow while still capturing microparticles. Unlike denser high-MERV filters that can strain your system, this filter balances filtration efficiency with low air resistance, making it compatible with most residential forced-air furnace and central air conditioning systems that accept a 17.5x23.5x1 custom-size filter.

The 17.5x23.5x1 is a non-standard custom size manufactured by 3M Filtrete to fit specific HVAC return vents and air handlers that don't accommodate common retail sizes. Always verify your existing filter's nominal size printed on the frame before ordering. The actual dimensions measure slightly smaller at 17.4 x 23.4 x 0.81 inches to ensure a proper slide-in fit without binding in the filter housing.