21x39x2 Geothermal Air Filters

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Products   MERV Rating Filter Life Annual Cost Value Pack
21x39x2 MERV8 SpiroPure O
MERV 8 Geothermal Filters (6 Pack)
  • $136.99
  • 6 Filters
  • ($22.83/filter)
MERV 8
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3 Months $91.33/yr
Best Value!

$136.99
6 Filters

($22.83/filter)
21x39x2 MERV11 SpiroPure O
MERV 11 Geothermal Filters (6 Pack)
  • $164.99
  • 6 Filters
  • ($27.50/filter)
MERV 11
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3 Months $109.99/yr

$164.99
6 Filters

($27.50/filter)
21x39x2 MERV13 SpiroPure O
MERV 13 Geothermal Filters (6 Pack)
  • $177.99
  • 6 Filters
  • ($29.67/filter)
MERV 13
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3 Months $118.66/yr

$177.99
6 Filters

($29.67/filter)
MERV Rating - Contaminant Removal Guide
MERV Rating   8 11 12 13
Lint & Dust  
Dust Mile Debris  
Pollen  
Mold Spores  
Pet Dander  
Auto Emissions  
Smoke  
Tobacco  
Bacteria  
Note: equals efficient removal of contaminant by filter.