Customer reviews from Filterbuy
Filterbuy - 21x21x4 MERV 13 Smoke & Allergy Defense, Electrostatic Pleated HVAC AC Furnace Air Filters Replacement (4-Pack) - Blue
Average customer rating
4.1
(1,155 Reviews)
Rating breakdown 1,155 reviews
5 Stars
716
4 Stars
109
3 Stars
127
2 Stars
88
1 Star
115
Customer Reviews for Filterbuy - 21x21x4 MERV 13 Smoke & Allergy Defense, Electrostatic Pleated HVAC AC Furnace Air Filters Replacement (4-Pack) - Blue
Customer Rating
5
on July 11, 2025
Posted by: Lyndell K.
Purchased filters from them before always have been satisfied with them.
Written by a customer while visiting Filterbuy
Customer Rating
3
Do not fit.
on July 8, 2025
Posted by: Anonymous
Even though they say the right size, they are way too small and I cannot use them. I think they are just the wrong kind of filter. Can I please return them for a refund? Please let me know how to go about the return.
Written by a customer while visiting Filterbuy
Customer Rating
5
24x24x4 MERV 13 Pleated Air Filter
on July 7, 2025
Posted by: Priscila B.
[This review was collected as part of a promotion.] The 24x24x4 MERV 13 Pleated Air Filter is a high-efficiency filtration solution designed for commercial HVAC systems that require superior air quality. After testing and installing multiple units in a facility with moderate to heavy air circulation demands, here's a breakdown of its performance and overall value:Performance:The MERV 13 rating offers excellent filtration, capturing airborne particles as small as 0. 3 microns. This includes allergens like pollen, dust mites, mold spores, pet dander, and even bacteria and virus carriers. Its particularly beneficial in environments prioritizing indoor air qualityoffices, churches, schools, healthcare facilities, and multi-use buildings.Build Quality:This filter features a durable pleated design with a rigid frame that holds up well under consistent airflow. The pleats are evenly spaced and well-constructed, maximizing surface area for particle capture without causing significant pressure drop. The filter media is moisture-resistant and doesnt sag or collapse under typical HVAC stress.Installation:Standard sizing ensures a snug and proper fit into most 24x24x4 filter racks or housings. Installation is straightforward and hassle-free, with clear directional airflow markings on the frame. The rigid design helps prevent bowing or bypass.Longevity:With normal use, the filter lasts approximately 36 months depending on air quality and system usage. Facilities with higher occupancy or environmental pollutants may require more frequent replacements, but the filter maintains integrity over its full lifespan.Value:While priced slightly higher than lower-rated filters (MERV 8 or MERV 11), the performance upgrade is well worth the investment, especially for facilities aiming to improve IAQ (Indoor Air Quality) and reduce strain on HVAC systems over time.Overall Rating: (4. 8/5)The 24x24x4 MERV 13 Pleated Air Filter is a reliable, high-performance choice for those needing enhanced air filtration without compromising HVAC system efficiency. Its durability, ease of use, and exceptional filtering capabilities make it a solid go-to option for professional facility management and maintenance.
Written by a customer while visiting Filterbuy
Customer Rating
4
so far so good, easy
on July 2, 2025
Posted by: Caroline H.
so far so good, easy to install into the HVAC system. . . will wait and see if it works long term.
Written by a customer while visiting Filterbuy
Customer Rating
2
Size matters
on June 28, 2025
Posted by: Anonymous
While I should have paid more attention to the dimensions, the 1/2" difference in height and width means that the so-called 20x20 flops around in my filter cabinet. Just buy a 3M which will actually fit. The blue filter color is nice.
Written by a customer while visiting Filterbuy
Customer Rating
5
Very sloppy fit. The actual
on June 28, 2025
Posted by: Anonymous
Very sloppy fit.The actual size should be at least twenty by twenty five by four
Written by a customer while visiting Filterbuy
Customer Rating
5
Great filters
on June 27, 2025
Posted by: Anonymous
Wouldnt buy anywhere else great quality and pricing
Written by a customer while visiting Filterbuy
Customer Rating
5
Does an excellent job of
on June 24, 2025
Posted by: Anonymous
Does an excellent job of keeping the air clean and controls the dust. Its nominal size fits where other 4" filters won't. Excellent product.
Written by a customer while visiting Filterbuy