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Best furnace filters - September 2025

Last Updated - September 25, 2025

1
Best Choice

✖
Our rankings are cleverly generated from the algorithmic analysis of thousands of customer reviews about products, brands, merchant’s customer service level, popularity, trends and more. The rankings reflect our opinion and should be a good starting point for shopping.

AIRx Filters

AirX Filters MERV 16 Furnace Filter Replacement for Lennox X6669 Filter - 21x26x4

AIRx Filters

$171.53

More Details
Main highlights
- Versatile Compatibility: This high-performance filter is not just limited to the X6669 model; it also serves as an excellent replacement for the PCO-20C and PCO-20P filters. Upgrade your home’s air quality with a filter that adapts effortlessly to various systems, ensuring you get the best air filtration no matter your HVAC setup.
- Premium Air Quality: The MERV 16 Replacement Filter for Lennox X6669 is designed to capture a wide variety of airborne particles, ensuring clean and fresh air in your home. As a direct replacement for the X6667 and X6669 models, it fits seamlessly into your HVAC system, offering you peace of mind and improved indoor air quality without the hassle of complicated installations.
- Perfect Fit Dimensions: Measuring 21x26x4 inches, this filter is engineered to fit your Lennox system perfectly. No more worries about awkward sizing or performance issues; simply replace your old filter and enjoy the enhanced air purification features. This filter is a must-have for maintaining the efficiency of your heating and cooling systems.
- Long-Lasting Performance: Built to last and designed for easy replacement, the MERV 16 Replacement Filter allows you to enjoy optimal air quality without frequent changes. Trust in a filter that provides consistent performance over time, keeping your Lennox system running smoothly while effectively reducing airborne pollutants.
- Enhanced Dust and Allergen Capture: Designed to trap common household allergens, dust, and pet dander, the MERV 16 filter helps create a healthier living environment. With its advanced filtration technology, you can breathe easier and reduce allergy symptoms while enjoying a comfortable home atmosphere all year round.
$171.53
2

✖
Our rankings are cleverly generated from the algorithmic analysis of thousands of customer reviews about products, brands, merchant’s customer service level, popularity, trends and more. The rankings reflect our opinion and should be a good starting point for shopping.

Filtrete

Filtrete 16x25x4 AC Furnace Air Filter, MPR 1000, MERV 11, Fits Lennox & Honeywell Devices, Allergen Defense, Electrostatic Air Cleaning Filter, 4-Pack (actual size 15.88 x 24.56 x 4.31)

Filtrete

$104.98

$116.08
(9% Off)

More Details
Main highlights
- SMART APP: Use the Filtrete Smart App (iOS or Android) to set 90-, 180- or 365-day reminders to change your air filter
- MOST TRUSTED: Filtrete Brand is North America’s most trusted brand of HVAC Filters, based on 2024 Sago US Brand Health Survey of Residential HVAC Air Filters
- MAKE YOUR HOME YOUR SANCTUARY: 1000 MPR + MERV 11 rating helps capture up to 2X more microparticles than MERV alone(2)
- EXCLUSIVE TECHNOLOGY: Designed with exclusive Filtrete 3-in-1 technology to pull in and trap unwanted particles, allowing cleaner air to flow through
- DIFFERENT FROM NOMINAL SIZE: Slightly different from the nominal size, this air filter’s exact dimensions are 15.88 in x 24.56 in x 4.31 in, This item is a 1-pack of a 12-month Filtrete Air Filter
- DESIGNED TO FIT: Honeywell and Lennox brand media air cleaners
- CHANGE YOUR FILTER OFTEN: For optimal performance, make sure to change your 4-inch filter at least once every 12 months
- CERTIFIED: This furnace filter is CERTIFIED asthma and allergy-friendly (2) and helps capture dust, lint and other allergens in your household air
$104.98
$116.08 (9% Off)
3
Best Value
26% Off

✖
Our rankings are cleverly generated from the algorithmic analysis of thousands of customer reviews about products, brands, merchant’s customer service level, popularity, trends and more. The rankings reflect our opinion and should be a good starting point for shopping.

Filtrete
26% Off

Filtrete 16x25x1 AC Furnace Air Filter, MERV 11, MPR 1000, Micro Allergen Defense, 3-Month Pleated 1-Inch Electrostatic Air Cleaning Filter, 4 Pack (Actual Size 15.69 x 24.69 x 0.81 in)

Filtrete

$43.98

$59.75
(26% Off)

More Details
Main highlights
- VERSATILE USES: Works for changing the air filters in your furnace, air conditioner/heating system or HVAC system
- SMART APP: Use the Filtrete Smart App (iOS or Android) to set 30-, 60- or 90-day reminders to change your air filter
- MOST TRUSTED: Filtrete Brand is North America’s most trusted brand of HVAC Filters, based on 2024 Sago US Brand Health Survey of Residential HVAC Air Filters
- MAKE YOUR HOME YOUR SANCTUARY: 4-pack of 3-month pleated Filtrete 16x25x1 MERV 11 MPR 1000 AC Furnace Air Filter helps capture unwanted particles from your household air to contribute to a cleaner, fresher home environment
- EXCLUSIVE TECHNOLOGY: Designed with Filtrete 3-in-1 technology to pull in and trap unwanted particles, allowing cleaner air to flow through
- COUNTLESS MICROPARTICLES: With a 1000 MPR and MERV 11 rating, your Filtrete Filter will help capture many microparticles from the air passing through it
- CHANGE YOUR FILTER OFTEN: For optimal performance, make sure to change your filter at least once every 90 days
- CERTIFIED: This furnace filter is CERTIFIED asthma and allergy-friendly (2) and helps capture dust, lint and other allergens in your household air
$43.98
$59.75 (26% Off)
4

✖
Our rankings are cleverly generated from the algorithmic analysis of thousands of customer reviews about products, brands, merchant’s customer service level, popularity, trends and more. The rankings reflect our opinion and should be a good starting point for shopping.

Filtrete

Filtrete 20x25x5 AC Furnace Air Filter, MPR 1000, MERV 11, Fits Lennox Devices, Allergen Defense, Electrostatic Air Cleaning Filter, 2-Pack (actual size 19.63 x 24.75 x 4.31 in)

Filtrete

$49.99

More Details
Main highlights
- SUBSCRIBE AND SAVE: On your first order, simply click on "Subscribe and Save" to set up your delivery schedule and save up to 10% on your orders
- SUBSCRIBE AND SAVE: On your first order, simply click on "Subscribe and Save" to set up your delivery schedule and save up to 10% on your orders
- RECYCLED CONTENT: Verified to contain at least 50% recycled content by GreenCircle Certified, a third-party auditor
- MOST TRUSTED: Filtrete Brand is North America’s most trusted brand of HVAC Filters, based on 2024 Sago US Brand Health Survey of Residential HVAC Air Filters
- MAKE YOUR HOME YOUR SANCTUARY: 1000 MPR + MERV 11 rating helps capture up to 2X more microparticles than MERV alone(2)
- FOR RESIDENTIAL use only
- EXCLUSIVE TECHNOLOGY: Designed with exclusive Filtrete 3-in-1 technology to pull in and trap unwanted particles, allowing cleaner air to flow through
- DIFFERENT FROM NOMINAL SIZE: Slightly different from the nominal size, this air filter’s exact dimensions are 19.63 in x 24.75 in x 4.31 in, This item is a 2-pack of 12-month Filtrete Air Filters
- DESIGNED TO FIT: Lennox brand media air cleaners
- CHANGE YOUR FILTER OFTEN: For optimal performance, make sure to change your 5-inch filter at least once every 12 months
$49.99
5

✖
Our rankings are cleverly generated from the algorithmic analysis of thousands of customer reviews about products, brands, merchant’s customer service level, popularity, trends and more. The rankings reflect our opinion and should be a good starting point for shopping.

Filtrete

Filtrete 16x25x4 AC Furnace Air Filter, MPR 1000, MERV 11, Fits Lennox & Honeywell Devices, Allergen Defense, Electrostatic Air Cleaning Filter, 2-Pack (Actual Size 15.88x24.56x4.31 in)

Filtrete

$54.20

More Details
Main highlights
- SMART APP: Use the Filtrete Smart App (iOS or Android) to set 90-, 180- or 365-day reminders to change your air filter
- MOST TRUSTED: Filtrete Brand is North America’s most trusted brand of HVAC Filters, based on 2024 Sago US Brand Health Survey of Residential HVAC Air Filters
- MAKE YOUR HOME YOUR SANCTUARY: 1000 MPR + MERV 11 rating helps capture up to 2X more microparticles than MERV alone(2)
- EXCLUSIVE TECHNOLOGY: Designed with exclusive Filtrete 3-in-1 technology to pull in and trap unwanted particles, allowing cleaner air to flow through
- DIFFERENT FROM NOMINAL SIZE: Slightly different from the nominal size, this air filter’s exact dimensions are 15.88 in x 24.56 in x 4.31 in, This item is a 2-pack of 12-month Filtrete Air Filters
- DESIGNED TO FIT: Honeywell and Lennox brand media air cleaners
- CHANGE YOUR FILTER OFTEN: For optimal performance, make sure to change your 4-inch filter at least once every 12 months
- CERTIFIED: This furnace filter is CERTIFIED asthma and allergy-friendly (2) and helps capture dust, lint and other allergens in your household air
$54.20

Best furnace filters - September 2025

AirX Filters MERV 16 Furnace Filter Replacement for Lennox X6669 Filter - 21x26x4

Filtrete 16x25x4 AC Furnace Air Filter, MPR 1000, MERV 11, Fits Lennox & Honeywell Devices, Allergen Defense, Electrostatic Air Cleaning Filter, 4-Pack (actual size 15.88 x 24.56 x 4.31)

Filtrete 16x25x1 AC Furnace Air Filter, MERV 11, MPR 1000, Micro Allergen Defense, 3-Month Pleated 1-Inch Electrostatic Air Cleaning Filter, 4 Pack (Actual Size 15.69 x 24.69 x 0.81 in)

Filtrete 20x25x5 AC Furnace Air Filter, MPR 1000, MERV 11, Fits Lennox Devices, Allergen Defense, Electrostatic Air Cleaning Filter, 2-Pack (actual size 19.63 x 24.75 x 4.31 in)

Filtrete 16x25x4 AC Furnace Air Filter, MPR 1000, MERV 11, Fits Lennox & Honeywell Devices, Allergen Defense, Electrostatic Air Cleaning Filter, 2-Pack (Actual Size 15.88x24.56x4.31 in)

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