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Furnace Filters
All HVAC systems need air filters - DiscountFurnaceFilter.com carries air filters for...
FAST SHIPPING
Orders placed by 5 PM EST typically ship the same day so your filters arrive fast and ready to use. We carry all popular sizes and offer free shipping on purchases over $50, making it easy to keep clean air flowing and your system running smoothly.
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HERITAGE
For over seven decades our family has been dedicated to helping homeowners breathe easier. What began as a small-town HVAC shop has grown into a trusted online destination for quality air filters and supplies, still driven by the same care and values that started it all.
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QUALITY
We offer filters and home comfort essentials from trusted names like Lennox, Honeywell, Filtrete, and Aprilaire. Each order is packed with care and delivered fast. With Discount Furnace Filter you can expect top brands, responsive support, and better air for your home.
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Lennox X6675 HCF20-16 | 20"x25"x5" Carbon Clean Air Filter MERV 16
Regular price From $113.91 USDRegular priceUnit price per -
Lennox X6670 HCF16-11 16" x 25" x 5" - Healthy Climate MERV 11 Replacement Filter
Regular price From $41.37 USDRegular priceUnit price per -
Lennox X6673 HCF20-11 (20 x 25 x 5) Healthy Climate MERV 11 Replacement Filter
Regular price From $44.26 USDRegular priceUnit price per -
Lennox X6672 HCF16-16 | 16" x 25" x 5" MERV 16 Carbon Clean Healthy Climate Replacement Filter
Regular price From $87.15 USDRegular priceUnit price per
TESTIMONIALS
What our customers say about us
How do I know my filter size?
Check your existing filter — the size is usually printed on the frame. If not, measure length, width, and depth (in inches) to find the correct replacement.
How often should I replace my filter?
It depends on filter size, MERV rating, and your home’s conditions. Many homeowners replace every 60–90 days under average use. If you have pets, allergies, or high system use, you may need to change more often. Some high-efficiency filters can last 6–12 months in mild conditions. Always check your manufacturer’s recommendations for the best schedule for your system.
What is a MERV rating and what should I choose?
MERV (Minimum Efficiency Reporting Value) shows how well a filter captures particles between 0.3–10 microns. A MERV 8–11 is a great balance for most homes (dust, pollen, pets), while MERV 13+ is better for allergy, asthma, or smoke concerns — if your HVAC system can handle the higher airflow restrictions.
Do higher-rated filters harm my HVAC system?
They can if your system isn’t designed for them. Higher MERV filters block more particles but may reduce airflow. Always check your system’s specs or manual before moving up.
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