Filterbuy Pet & Allergy Defense MERV 11 Air Filter

Why it matters

The Filterbuy Pet & Allergy Defense MERV 11 Air Filter is a pleated furnace and air conditioner filter rated MERV 11. Its size table lists 147 sizes in 1-inch, 2-inch, 4-inch, 5-inch depths, each linked to its own listing.

Sizes by depth: 1-inch: 96 sizes (from 10x10x1 to 30x36x1); 2-inch: 33 sizes (from 10x10x2 to 30x36x2); 4-inch: 17 sizes (from 12x20x4 to 25x25x4); 5-inch: 1 sizes (from 20x25x5 to 20x25x5).

MERV 11 is the usual allergy upgrade: it catches most pollen, pet dander and mold spores, and part of the 1 to 3 micron range.

The listing sells it as 4 filters per pack.

As general guidance, check a 1-inch filter monthly and change it every one to three months; deeper 4- and 5-inch filters usually last six to twelve months.

The Filterbuy listing names 4 filters per box.

Compared with the Filterbuy Smoke & Allergy Defense MERV 13 Air Filter: MERV rating 11 here vs 13.

Who it's for, and who should skip it

Sizes and where to buy each

Each size below links to that exact size; check the nominal size printed on the frame of the filter you have now.

Sizes are nominal (the label size); actual dimensions are usually about 1/4 to 1/2 inch smaller so the filter slides into the slot.

Pros and cons

Limitations to weigh

• Specifications are the maker's or seller's own figures; check fit against your equipment's model number and the actual size.

Specifications

The bracket shows where each figure comes from.

Alternatives worth comparing

Glasfloss MERV 11 1-inch Furnace FilterMERV 11 from Glasfloss.

Aerostar Pleated MERV 11 Air FilterMERV 11, MPR 1200 from Aerostar.

Amazon Basics MERV 11 1-inch Furnace FilterMERV 11 from Amazon Basics.

More hvac and furnace filters we cover

• Aerostar MERV 13 1-inch Furnace Filter
• Nordic Pure 16x24x1 Pleated MERV 12 Air Filter
• Filtrete 4-Inch MPR 1000 (MERV 11) Air Filter
• AirPurete MERV 8 4-inch Replacement Filter for Filtrete
• AIRx MERV 11 4-inch Furnace Filter

All hvac and furnace filters, compared in one table · Every Filterbuy product we cover

Final verdict

A practical choice for allergy households. Check the size table and order the exact size on your old filter's frame.

Where to buy

Questions buyers ask