18" X 20" X 1" Lifetime Permanent Washable Filter

Permatron 3856-1820LRG | Our#: 178136
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18" X 20" X 1" Low-Resistance, Electrostatic Permanent Washable Filter

  • 18x20x1" Nominal
  • 17½x19½x⅞" Actual
  • Washable

$39.99 $51.99
In Stock
Ships Monday, Aug. 3rd
5 stars (2 reviews)

18" X 20" X 1" Low-Resistance, Electrostatic Permanent Washable Filter

(actual size - 17-1/2" X 19-1/2" X 3/4")

Never buy another filter!  Our permanent washable filter is designed to provide great value and last a lifetime.   This durable filter is constructed with a combination of woven polypropylene media supported by heavy-duty steel mesh in a galvanized steel frame. The filter carries a lifetime warranty and is ideal for heat pumps, sensitive 90+ efficient furnaces and systems with limited air flow.  This is the best and last filter you will ever buy.


  • Designed to minimize initial resistance to airflow
  • Reduces the number of pollutants and allergens in recirculated air and keeps your HVAC system clean
  • Uses natural static electricity to attract and capture airborne particles
  • Washable - cleans up in minutes
  • Includes anti-microbial polymeric protection
  • Durable steel frame
  • Dirt won't get caught in the filter during washing - due to specially-designed drainage ports in the filter frame
  • Lifetime warranty

Clean Monthly by rinsing your filter with running water.  For tough dirt and/or grease, use a mild detergent (i.e., 409 or Simple Green) and rinse thoroughly with warm water.

Average arrestance efficiency - 74%
Initial resistance - 0.07" w.g.
Dust holding capacity - 110 grams

18" X 20" X 1" Lifetime Permanent Washable Filter
18" X 20" X 1" Lifetime Permanent Washable Filter Reviewed by 2
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Displaying reviews 1-2:

By Dennis L.


 5 of 5

18" X 20" X 1" Lifetime Permanent Washable Filter


The electrician who installed my new electric furnace never once mentioned a lifetime filter was available. I learned about your filters from an old friend who lives on a poverty level income. Your filter is not only affordable, but it saves a lot of money in only one year's time. I was using paper filters, changing them once a month. They were costing me $15.00 per month (not too bad) but over time it really added up. I paid around $40.00 for your lifetime washeable filter and am very happy with it. I even bought a 2nd one for when I change out the filter once a month, that way I don't have to shut down the unit while the newly cleaned filter drys. Your filter saves me about $175.00 a year, or around $1800.00 in ten years. Every penny counts. Thanks.

BOTTOM LINE: Yes, I recommend this product

By r m.


 5 of 5

still have one of the old filters to use before installing the permanent filter


quick delivery.

BOTTOM LINE: Yes, I recommend this product

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