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Whole House Air Filters

20x25x5 MERV 11 Air Bear 259112-102 Compatible 2 Pack by Atomic Filters

Size Guide

MERV 11 Air Bear Compatible Whole House Air Filter By Atomic Filters is a  Deep Pleat Nominal size 20" x 25" x 5"MERV, or Minimum Efficiency Reporting Value, indicates when a filter will be least efficient. So the higher the MERV rating, the more efficient the filter. Uses 100% electro-statically charged synthetic fibers. Also provides minimum resistance and higher dirt holding capacity to maximize filter life. Pre-applied gasket on the assembled filter prevents air by-pass. These replacement filters effectively trap and remove airborne particles like pollen, dust, dirt, mold, and spores as small as 1 micron. Perfect for Reducing allergy causing particles in your household air with the Trion 259112-102 Compatible by Atomic Filters replacement  for Air Bear HVAC filter. The pleated non-woven filtration media traps microscopic particles that reduce air quality and irritate sinuses.Allergy Suffers related  having symptoms inside you home such as a runny nose, sneezing, headaches, or trouble breathing along with other more severe respiratory problems like asthma, then it would be a good time to replace your air filter. Replacement filter for Air Bear 2000 Air Cleaner Air Bear Classic Air Cleaner Air Bear Plus 2000 Air Cleaner Son of a Bear Air Cleaner Air Bear Right Angle Air Cleaner Air Bear Supreme 2000 Air Cleaner Air Cleaner Model 435790-027 Air Cleaner Model 455602-025 Part # 229990-002 Part # 229990-102 Part # 248713-102 Part # S1-FM10202505 Totaline # P101-2025

  • Part Number: 259112-102 Compatible
  • Dimensions: 20x25x5 (Actual:  19 3/4" X 24-1/4" X 4 7/8")
  • MERV Rating: 11
  • Easy replacement
  • Non-woven, 5" thick, pleated Air Bear media filter traps particles as small as one micron
  • Fits most popular models of media air cleaners.
  • Qty: 2 filters

The Trion 259112-102 Compatible by Atomic Filters Fits Select Air Cleaners That Use 20x25x5 Filters With The Following Models:

  • 259112-102 455602-025 Part # 229990-002 Part # 229990-102 Part # 248713-102 Part # S1-FM10202505 Totaline # P101-2025

Customer Reviews

Based on 2 reviews
Wrong size

Although they said they were compatible the size was wrong 20 25 5. On closer inspection the width needed was 4 3/8 not 4 7/8. The site said this was the correct replacement for the model I have. I have two big filters that don't fit.

Excellent service and website was easy to navigate

I will order from them next time I need furnace filters. I like the no delivery cost. Thanks,

Nominal Vs. Actual Sizes: Finding the Right Air Filter Size

Buying the Correct Size Air Filter- The Most Important Thing to Know 

When you are buying your air filter online most important thing to know is Air Filters have two sizes that you need to understand the Nominal size and the Actual Size. Not understanding these numbers often leads to consumers purchasing a filter that does not fit their Furnace or HVAC system. See the complete list of Air Filters by Size Rating and Brand.

Nominal vs Actual air filter size by Atomic


Understanding Nominal Filters Size Could Save You Time and Money

Not understanding the Nominal Filter Size is the primary culprit for incorrectly purchased filters.The Nominal Size is the usually the dimensions used to Label the filter. For instance 16x20x1. These dimensions are a rounded value on the filters actual measurements. The actual measurements on this filter may be 15.5x19.5x.75, but that could vary by brand and manufacturer. So in order to make sure you have the correct size filter, especially if you are replacing with a different brand it is important to confirm the actual size on the filter. When purchasing filters on the internet the Nominal size is usually found in the product title.

Actual Filter Size- The Key to Making the Right Replacement Filter Purchase

The actual size as you might have guessed are the actual dimensions of the filter by length, width and thickness. This size is often on the filter right below the Nominal size and is usually labeled as the actual size. When you are buying a filter online the actual size is sometime in the product bullet point or the product description. If your filter does not have actual dimensions on the outside of the filter, you can measure you filter to get the correct dimensions. Some brands have a foam gasket on the outside of the filter, in this case, you will want to make sure you have a compatible actual size and that it also has the foam to ensure a snug fit. 

Lennox Air Filter X0851 with Foam strips

Examples of Nominal and Actual Sizes

 Size  Example 1  Example 2
Nominal Size 20x20x1 16x20x1
Actual Size 19.5x19.5x.75 15.75x19.75x.75


 Furnace filters should fit securely but should not have to be forced into position. If you have to force the filter into its slot, then it is probably too big. Forcing an improper filter size in a filter can cause it to buckle, damaging the filter or reducing its ability to function properly. Filters are a smaller than their slot to allow for easy replacement. Some HVAC units may need a filter with dimensions that are unique or uncommon. In these cases, a custom filter needs to be ordered.

Find Your Filter Sizes Easy in 1" Deep Filters , 2" Deep Filters, 4" Deep Filters