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AC Furnace Air Filter
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Product Description

Filter Size: 18x18x4

Actual Size: 17.5×17.5×4

Actual Size Fraction : 17-1/2×17-1/2×4

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18x18x4 Air Filters

Improve the air you breathe in your home or workplace with our advanced 18x18x4 Air Filters, available for easy online purchase exclusively from Custom Filters Direct. Engineered with precision and designed for optimal efficiency, these filters promise to elevate your indoor air quality, fostering a healthier and more comfortable atmosphere.

Key Features:

  • Versatile Sizing for Various HVAC Systems: The 18x18x4 size ensures compatibility with a wide range of HVAC systems, making these filters a versatile solution for both residential and commercial applications. Experience the benefits of cleaner air, tailored to your specific air filtration needs.
  • Extended Lifespan: Lasts Up to 3 Months: Enjoy the convenience of an extended filter lifespan, providing up to 3 months of consistent and reliable air quality improvement. This longevity reduces the need for frequent replacements, offering ease of use and peace of mind in your busy life.
  • Supercharged Pleated Panel Filtering Media: These filters feature supercharged pleated panel filtering media, meticulously designed to capture fine airborne allergens. From dust, smoke, and dander to mold, pet dander, and dust mites, these filters act as a magnet for particulates, contributing to a superior indoor air quality experience.
  • Up to 30 Times More Efficient: Experience unparalleled efficiency with these filters, proven to be up to 30 times more effective at capturing allergens compared to ordinary fiberglass filters. Enjoy a cleaner and healthier environment, with enhanced particle capture capabilities to address various airborne contaminants.
  • Uniform Pleat Shape for Enhanced Performance: The uniform pleat shape not only increases the dust holding capacity of the filters but also maximizes airflow. This thoughtful design ensures optimal performance, contributing to improved air circulation throughout your space.
  • Proudly Made in the USA: Rest assured knowing that your filters are proudly manufactured in the United States. By choosing our filters, you support domestic production and benefit from the assurance of quality craftsmanship that aligns with the highest standards.


Upgrade your air filtration system today by adding the 18x18x4 Air Filters from Custom Filters Direct to your cart. Experience the peace of mind that comes with breathing cleaner, fresher air in your indoor environment. Take a confident step towards creating a healthier and more comfortable living or working space.