21x26x4 Lennox X6667 / X6669 Air Filters

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Products   MERV Rating Filter Life Annual Cost Value Pack
21x26x4 Lennox MERV8 SpiroPure N
Lennox Compatible (MERV 9)
  • $50.99
  • 2 Filters
  • ($25.50 / filters)
MERV 8
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6 Months $50.99
Best Value!

$50.99
2 Filters

($25.50 / filter)
Aprilaire 261 Aprilaire
261 Air Cleaner Filter
  • $112.99
  • 1 Filters
  • ($112.99 / filters)
MERV 10
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12 Months $112.99

$112.99
1 Filters

($112.99 / filter)
Lennox X6667 Lennox
Lennox Air Filters X6667
    5 stars
  • $61.99
  • 1 Filters
  • ($61.99 / filters)
MERV 11
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6 Months $123.98

$61.99
1 Filters

($61.99 / filter)
Lennox X8348 Lennox
X8348 Healthy Climate PureAir Maintenance Kit
  • $386.99
  • 1 Filters
  • ($386.99 / filters)
MERV 11
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12 Months $386.99

$386.99
1 Filters

($386.99 / filter)
21x26x4 Lennox MERV13 SpiroPure N
Lennox Compatible (MERV 13)
  • $57.99
  • 2 Filters
  • ($29.00 / filters)
MERV 13
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6 Months $57.99

$57.99
2 Filters

($29.00 / filter)
X6669 21x26x4 SpiroPure O
Lennox X6669 Replacement (MERV16)
  • $114.99
  • 1 Filters
  • ($114.99 / filters)
MERV 13
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6 Months $229.98

$114.99
1 Filters

($114.99 / filter)
Lennox X6669 Lennox
X6669 Healthy Climate 21" x 26" x 4"
  • $168.99
  • 1 Filters
  • ($168.99 / filters)
MERV 13
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6 Months $337.98

$168.99
1 Filters

($168.99 / filter)
Lennox X8344 Lennox
X8344 Healthy Climate PureAir Upgrade Kit
  • $318.99
  • 1 Filters
  • ($318.99 / filters)
MERV 13
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12 Months $318.99

$318.99
1 Filters

($318.99 / filter)
Lennox X8345 Lennox
X8345 Healthy Climate PureAir Upgrade Kit
  • $458.99
  • 1 Filters
  • ($458.99 / filters)
MERV 13
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12 Months $458.99

$458.99
1 Filters

($458.99 / filter)
MERV Rating - Contaminant Removal Guide
MERV Rating   8 11 12 13
Lint & Dust  
Dust Mite Debris  
Pollen  
Mold Spores  
Pet Dander  
Auto Emissions  
Smoke  
Tobacco  
Bacteria  
Note: equals efficient removal of contaminant by filter.