Aerostar Air Filter

This filter is designed as a direct replacement for Honeywell FC100A1011 and Lennox X0585 systems. Always verify your current filter's actual dimensions against the 19 3/4" x 19 7/8" x 4 3/8" measurements provided to ensure a proper fit.

Choose MERV 8 for basic dust and pollen filtration, MERV 11 for better protection against pet dander and smoke, or MERV 13 if you need to capture finer particles like bacteria and virus carriers. Higher MERV ratings provide better air quality but may require your HVAC system to work slightly harder to pull air through the filter.

While we recommend changing the filter every 6 months for optimal performance, you may need to replace it sooner if you have pets, live in a dusty environment, or run your HVAC system constantly. Checking the filter visually every 3 months is a good practice to gauge if it needs an early swap.

The deep pleat design increases the total surface area of the filter media, allowing it to trap more particles over a longer period. This high-capacity construction helps maintain consistent airflow while extending the time between necessary replacements.

Because this is a deep pleat filter, it is engineered to maintain high airflow even as it accumulates dust. However, if you notice your system struggling or your energy bills rising, it is a sign that the filter is fully loaded and needs to be replaced.