Filterbuy 21x22x1 Air Filter MERV 13 Optimal Smoke & Allergy Defense (4-Pack), Electrostatic Pleated HVAC AC Furnace Filters Replacement, Made in USA (Actual Size: 20.50 x 21.50 x 0.75)

These filters are the best made filters I have found to date. Sharp folds, tight construction. They filter so well that I had to tape them, otherwise they are vacuumed by my Carrier system. Unfortunately, filter housings are very poorly designed in most AC systems. By blue taping the filters you prevent any filtering loss that will happen with most systems. Air quality has improved by a huge massive lot vs Merv 8 that I was using. These Merv 13 even help with fumes and cooking smells. I have some serious allergies and these filters are definitely a game changer for those who spend more time at home. I feel soo much better. Extremely happy with the change and the filtration capabilities. I have noticed no change in my carrier system performance whatsoever. I'm sure it is harder for the blower motor to use merv 13 filters, but my AC handles it perfectly. Merv 13 could be too much for some older AC systems, so always consider check your model and capabilities of it. My AC is purposely undersized. I run my AC for about 10 to 15 hours a day during the long Central FL summers. You can see how the new vs old looks in the picture after a hard month of use. If you can, get these, you will love them.

Does a good job of cleaning the air. Good quality, fit properly. Lasts very well.

The 4" Filterbuy has a 4" slim fit option. Filters are good quality and arrived promptly.

Ordered 16x20x4. The actual size is a bit short. It’s really beneficial to have the filter true to the actual size namely, 16x20x4 . 15.5” is not 16”

These work great! and a good price.

Excellent Product

I’ve been using these MERV 13 16x20x1 filters for a few months now, and the difference in air quality is noticeable. They catch everything—dust, pollen, and pet dander. My allergies have improved, and the house just feels cleaner. They fit perfectly in my HVAC system and last the full 3 months (sometimes longer, depending on the season). Just be aware, since they’re a higher MERV rating, your system might have to work a bit harder—but mine has handled it just fine. If you want cleaner air, especially with pets, allergies, or sensitive lungs, these are 100% worth it.

My hvac uses the 14x24x1 filter size. Every other brand I would buy, did not fit correctly. I had to bend the corners to fit it in. But these are slightly smaller, and they fit perfectly.