Home > Air Filters > Lennox Air Filters > Box Filters

Thick Lennox Filters for Furnace

Your filter needs to be replaced regularly. Check your filter when your system is in the off position, by pulling the filter straight out from its housing to inspect it. If your filter looks dirty, it will restrict airflow to your cleaner, AC or furnace.
We offer three to five-inch Lennox air filters designed for various systems. If you're not sure which box filter for Lennox you need, contact us!


Tips for replacement:

Always ensure you point the airflow arrow toward the furnace chamber. For the sake of convenience, it's a good idea to write the date when you changed your filter on the filter itself before inserting it into the furnace. Check your filter in three months and observe its condition. Lennox box-style filters are designed to be replaced every six-12 months, but depending on the air quality around you, this might be more often.

Here at Filter Shipping, we carry a full line up of Lennox filters for your furnace, air conditioner, and air cleaner. Lennox also makes filters for other major brands, such as Honeywell, Air Bear, Aprilaire and more.

Sort By:
Page of 2
Lennox x0581 MERV 11 Filter Lennox x0583 MERV 11 Filter Lennox x6670 2-Pack Special
Lennox Healthy Climate
x0581 Box Filter
Nominal Size: 16" x 25" x 3"
Exact Size: 15.875" x 24.25" x 3"
Filter Rating: MERV 11
Expected Duration: 6 to 12 monthsReplacement For: Trion 255649-101
Lennox Healthy Climate
x0583 Box Filter
Nominal Size: 16" x 25" x 5"
Exact Size: 16" x 24.75" x 4.375"
Filter Rating: MERV 11
Expected Duration: 6 to 12 monthsReplacement For: Honeywell FC100A-1029 & FC200E-1029
Lennox Healthy Climate
x6670 2-Pack Special
Nominal Size: 16" x 25" x 5"
Exact Size: 15.75" x 24.75" x 4.375"
Filter Rating: MERV 11
Expected Duration: 6 to 12 months
Quantity in Case: 2
Lennox x6670 5-Pack Special Lennox x6670 MERV 11 Filter Lennox x6672 2-Pack Special
Lennox 16x25x5 x6670 Box Filter
Our Price: $27.00

(12)
Lennox Healthy Climate
x6670 5-Pack Special
Nominal Size: 16" x 25" x 5"
Exact Size: 15.75" x 24.75" x 4.375"
Filter Rating: MERV 11
Expected Duration: 6 to 12 months
Quantity in Case: 5
Lennox Healthy Climate
x6670 Box Filter
Nominal Size: 16" x 25" x 5"
Exact Size: 15.75" x 24.75" x 4.375"
Filter Rating: MERV 11
Expected Duration: 6 to 12 months
Lennox Healthy Climate
x6672 2-Pack Special
Nominal Size: 16" x 25" x 5"
Exact Size: 15.75" x 24.75" x 4.375"
Filter Rating: MERV 16
Expected Duration: 6 to 12 months
Allergen Grade: Premium
Quantity in Case: 2


Lennox x6672 5-Pack Special Lennox x6672 MERV 16 Filter Lennox x0584 MERV 11 Filter
Lennox Healthy Climate
x6672 5-Pack Special
Nominal Size: 16" x 25" x 5"
Exact Size: 15.75" x 24.75" x 4.375"
Filter Rating: MERV 16
Expected Duration: 6 to 12 months
Allergen Grade: Premium
Quantity in Case: 5
Lennox Healthy Climate
x6672 Box Filter w/ Carbon
Nominal Size: 16" x 25" x 5"
Exact Size: 15.75" x 24.75" x 4.375"
Filter Rating: MERV 16
Expected Duration: 6 to 12 months
Allergen Grade: Premium
Lennox Healthy Climate
x0584 Box Filter
Nominal Size: 16" x 26" x 5"
Exact Size: 16.375" x 26" x 5.156"
Filter Rating: MERV 11
Expected Duration: 6 to 12 months
Lennox 17"x26"x4" x6664 MERV 11 Box Filter Lennox 17"x26"x4" x6666 MERV 16 Box Filter Lennox x0585 2-Pack Special
Lennox Healthy Climate
x6664 Box Filter
Nominal Size: 17" x 26" x 4"
Exact Size: 16.625" x 26.75" x 4"
Filter Rating: MERV 11
Expected Duration: 6 to 12 months
Lennox Healthy Climate
x6666 Box Filter
Nominal Size: 17" x 26" x 4"
Exact Size: 16.625" x 26.75" x 4"
Filter Rating: MERV 16
Expected Duration: 6 to 12 months
Lennox Healthy Climate
x0585 2-Pack Special
Nominal Size: 20" x 20" x 5"
Exact Size: 20" x 19.75" x 4.375"
Filter Rating: MERV 11
Expected Duration: 6 to 12 months
Replacement For: Honeywell FC100A1011 & FC200E1011
Quantity in Case: 2


Lennox x0585 MERV 11 Filter Lennox x7935 2-Pack Special Lennox x7935 5-Pack Special
Lennox Healthy Climate
x0585 Box Filter
Nominal Size: 20" x 20" x 5"
Exact Size: 20" x 19.75" x 4.375"
Filter Rating: MERV 11
Expected Duration: 6 to 12 months
Replacement For: Honeywell FC100A1011 & FC200E1011
Lennox Healthy Climate
x7935 2-Pack Special
Nominal Size: 20" x 20" x 5"
Exact Size: 20" x 19.75" x 4.375"
Filter Rating: MERV 16
Expected Duration: 6 to 12 months
Allergen Grade: Premium
Quantity in Case: 2


Lennox Healthy Climate
x7935 5-Pack Special
Nominal Size: 20" x 20" x 5"
Exact Size: 20" x 19.75" x 4.375"
Filter Rating: MERV 16
Expected Duration: 6 to 12 months
Allergen Grade: Premium
Quantity in Case: 5
Lennox x7935 MERV 16 Filter Lennox x0586 MERV 11 Filter Lennox 20"x25"x5" x1152 MERV 11 Box Filter
Lennox 20x25x5 x0586 Box Filter
Our Price: $29.00

(2)
Lennox 20x25x5 x1152 Box Filter
Our Price: $25.00

(2)
Lennox Healthy Climate
x7935 Box Filter w/ Carbon
Nominal Size: 20" x 20" x 5"
Exact Size: 20" x 19.75" x 4.375"
Filter Rating: MERV 16
Expected Duration: 6 to 12 months
Allergen Grade: Premium
Lennox Healthy Climate
x0586 Box Filter
Nominal Size: 20" x 25" x 5"
Exact Size: 20" x 24.75" x 4.375"
Filter Rating: MERV 11
Expected Duration: 6 to 12 months
Replacement For: FC100A-1037 & FC200E-1037
Lennox Healthy Climate
x1152 Air Bear Filter
Nominal Size: 20" x 25" x 5"
Exact Size: 19.75" x 24.25" x 5"
Filter Rating: MERV 11
Expected Duration: 6 to 12 months
Replacement For: 255649-102 & 229990-102
Lennox x6673 2-Pack Special Lennox x6673 5-Pack Special Lennox x6673 MERV 11 Filter
Lennox 20x25x5 x6673 Box Filter
Our Price: $29.00

(8)
Lennox Healthy Climate
x6673 2-Pack Special
Nominal Size: 20" x 25" x 5"
Exact Size: 19.75" x 24.75" x 4.375"
Filter Rating: MERV 11
Expected Duration: 6 to 12 months
Quantity in Case: 2


Lennox Healthy Climate
x6673 5-Pack Special
Nominal Size: 20" x 25" x 5"
Exact Size: 19.75" x 24.75" x 4.375"
Filter Rating: MERV 11
Expected Duration: 6 to 12 months
Quantity in Case: 5
Lennox Healthy Climate
x6673 Box Filter
Nominal Size: 20" x 25" x 5"
Exact Size: 19.75" x 24.75" x 4.375"
Filter Rating: MERV 11
Expected Duration: 6 to 12 months
Lennox x6675 2-Pack Special Lennox x6675 5-Pack Special Lennox x6675 MERV 16 Filter
Lennox Healthy Climate
x6675 Box 2-Pack Special
Nominal Size: 20" x 25" x 5"
Exact Size: 19.75" x 24.75" x 4.375"
Filter Rating: MERV 16
Expected Duration: 6 to 12 months
Allergen Grade: Premium
Quantity in Case: 2


Lennox Healthy Climate
x6675 Box 5-Pack Special
Nominal Size: 20" x 25" x 5"
Exact Size: 19.75" x 24.75" x 4.375"
Filter Rating: MERV 16
Expected Duration: 6 to 12 months
Allergen Grade: Premium
Quantity in Case: 5

Lennox Healthy Climate
x6675 Box Filter w/ Carbon
Nominal Size: 20" x 25" x 5"
Exact Size: 19.75" x 24.75" x 4.375"
Filter Rating: MERV 16
Expected Duration: 6 to 12 months
Allergen Grade: Premium
Lennox x0587 MERV 11 Filter Lennox 21"x26"x4" x6667 MERV 11 Box Filter Lennox 21"x26"x4" x6669 MERV 16 Box Filter
Lennox 20x26x5 x0587 Box Filter
Our Price: $29.00

(2)
Lennox 21x26x4 x6667 Box Filter
Our Price: $30.00

(1)
Lennox Healthy Climate
x0587 Box Filter
Nominal Size: 20" x 26" x 5"
Exact Size: 20.438" x 26" x 5.156"
Filter Rating: MERV 11
Expected Duration: 6 to 12 months
Lennox Healthy Climate
x6667 Box Filter
Nominal Size: 21" x 26" x 4"
Exact Size: 21.25" x 26" x 4"
Filter Rating: MERV 11
Expected Duration: 6 to 12 months
Lennox Healthy Climate
x6669 Box Filter
Nominal Size: 21" x 26" x 4"
Exact Size: 21.25" x 26" x 4"
Filter Rating: MERV 16
Expected Duration: 6 to 12 months
Lennox x8789 MERV 16 Filter Lennox x8790 MERV 16 Filter Lennox x8788 MERV 16 Filter
Lennox Healthy Climate
x8789 Box Filter
Nominal Size: 16" x 26" x 5"
Exact Size: 16.375" x 25.5" x 4.375"
Filter Rating: MERV 16
Expected Duration: 6 to 12 months
Allergen Grade: Premium
Lennox Healthy Climate
x8790 Box Filter
Nominal Size: 20" x 21" x 5"
Exact Size: 20" x 20.625" x 4.375"
Filter Rating: MERV 16
Expected Duration: 6 to 12 months
Allergen Grade: Premium
Lennox Healthy Climate
x8788 Box Filter
Nominal Size: 20" x 26" x 5"
Exact Size: 20" x 25.5" x 4.375"
Filter Rating: MERV 16
Expected Duration: 6 to 12 months
Allergen Grade: Premium