# Filterbuy 13x21.5x1 MERV 11 Air Filter, 4-Pack

Filterbuy 13x21.5x1 air filters are a four-pack of pleated MERV 11 replacements for compatible HVAC equipment. The listing gives the actual filter size as 12.88 x 21.50 x 0.75 inches, so confirm the installed filter dimensions before ordering.

- [Original product page](https://best-deals.pro/product/filterbuy-13x21-5x1-merv-11-air-filter-4-pack)
- [View offer](https://best-deals.pro/visit/filterbuy-13x21-5x1-merv-11-air-filter-4-pack)
- Market: US
- Language: en-US
- Currency: USD
- Brand: Filterbuy
- Category: Home & Kitchen > Appliance Parts & Accessories > Air & HVAC Filters
- Price: 48.56 USD
- Previous price: 53.96 USD
- Discount: 10%
- Price checked: 2026-11-11T11:58:07.331Z
- Rating: 4.6 / 5
- Reviews: 24122

Prices and deal status are the latest recorded data, not a guarantee of availability. Confirm the price and availability with the store.

## At a glance

- MERV 11 synthetic filter media, the listing claims it captures 95% of dust.
- Electrostatically charged media and 14 pleats per foot are claimed to support particle capture.
- Listing recommends replacing the filter every 90 days for optimal performance.
- Pleated construction with a beverage-board frame and dual wire backing, according to the listing.

## Pros

- Four filters are offered as a pack, reducing the need to reorder after each replacement.
- The stated actual size is included, which helps compare the filter against an existing filter or equipment slot.
- Listed compatibility covers several common HVAC devices, including furnaces, air conditioners and heat pumps.

## Specifications

### Identity
- Brand: Filterbuy
### Dimensions and installation
- Dimensions listed: 21.5"L x 12.88"W x 0.75"Th
- Actual size stated in listing: 12.88" x 21.50" x 0.75"
- Filter shape: Rectangular
- Mounting type: Slide In
- Construction: Pleated
### Filtration and compatibility
- MERV rating: 11
- Compatible devices: Air Cleaner, Air Conditioner, Furnace, HVAC System, Heat Pump
- Pleats per foot: 14 pleats per foot
### Materials and protection
- Material listed: Aluminum, Plastic, Polypropylene
- Maximum temperature: 200 °F

## Before you buy

- The title uses nominal 13x21.5x1 sizing, while the stated actual size is 12.88" x 21.50" x 0.75", compare the actual dimensions with your equipment's required filter size before purchase. Performance and longevity figures are manufacturer claims, not independently verified.

## A good fit for

- Buyers replacing a rectangular slide-in filter who have confirmed the listed actual dimensions fit.
- Households seeking a MERV 11 replacement filter for listed furnace, air-conditioner, heat-pump or HVAC use.

## Less suited to

- Buyers who need a filter matching a different actual size or whose equipment requires a different filtration rating.

## Customer feedback

The supplied customer evidence contains an aggregate rating of 4.6 out of 5 stars, but no review count or written feedback. The rating alone does not show what buyers liked or disliked, confirm fit using the stated actual dimensions, especially if your equipment requires a precise size.

## Frequently asked questions

### What size is this filter?
The listing gives the actual size as 12.88" x 21.50" x 0.75", the title uses nominal 13x21.5x1 sizing. Check your equipment's required dimensions before ordering.
### Which equipment is it listed for?
The listing names air cleaners, air conditioners, furnaces, HVAC systems and heat pumps. Confirm the filter size and requirements for your specific equipment.
### How often does the listing recommend replacement?
It recommends replacement every 90 days for optimal performance, actual replacement needs may depend on use and equipment.

## Alternative options

- [Filterbuy 13x20x1 Air Filter MERV 8 Dust & Allergy Defense \(2-Pack\) \| Electrostatic Pleated HVAC AC Furnace Filters Replacement, Made in USA \(Actual Size: 12.88 x 19.88 x 0.75\)](https://best-deals.pro/visit/filterbuy-13x21-5x1-merv-11-air-filter-4-pack)
- [Filterbuy 13x20x1 Air Filter MERV 8 Dust & Allergy Defense \(4-Pack\) \| Electrostatic Pleated HVAC AC Furnace Filters Replacement, Made in USA \(Actual Size: 12.88 x 19.88 x 0.75\)](https://best-deals.pro/visit/filterbuy-13x21-5x1-merv-11-air-filter-4-pack)
- [Filterbuy 13x20x1 Air Filter MERV 8 Dust & Allergy Defense \(6-Pack\) \| Electrostatic Pleated HVAC AC Furnace Filters Replacement, Made in USA \(Actual Size: 12.88 x 19.88 x 0.75\)](https://best-deals.pro/visit/filterbuy-13x21-5x1-merv-11-air-filter-4-pack)
- [Filterbuy 13x21.5x1 Air Filter MERV 13 Smoke & Allergy Defense \(4-Pack\) \| Electrostatic Pleated HVAC AC Furnace Filters Replacement, Made in USA \(Actual Size: 12.88 x 21.50 x 0.75\)](https://best-deals.pro/visit/filterbuy-13x21-5x1-merv-11-air-filter-4-pack)
- [Filterbuy 13x21.5x1 Air Filter MERV 8 Dust & Allergy Defense \(6-Pack\) \| Electrostatic Pleated HVAC AC Furnace Filters Replacement, Made in USA \(Actual Size: 12.88 x 21.50 x 0.75\)](https://best-deals.pro/visit/filterbuy-13x21-5x1-merv-11-air-filter-4-pack)
- [Filterbuy 13x21.5x1 Air Filter MERV 8 Dust & Allergy Defense \(3-Pack\) \| Electrostatic Pleated HVAC AC Furnace Filters Replacement, Made in USA \(Actual Size: 12.88 x 21.50 x 0.75\)](https://best-deals.pro/visit/filterbuy-13x21-5x1-merv-11-air-filter-4-pack)
- [Filter King 17x22x1 Air Filter MERV 8, AC Furnace Filters \(12-Pack\) \| Dust & Allergy Control \(Actual Size: 16.5 x 21.5 x .75\)](https://best-deals.pro/visit/filterbuy-13x21-5x1-merv-11-air-filter-4-pack)
- [Filterbuy 21x21.5x5 Air Filter MERV 8 Dust & Allergy Defense \(2-Pack\) \| Pleated HVAC AC Furnace Replacement for Trane Perfect Fit & American Standard \(Actual Size: 20.00 x 21.09 x 4.97\)](https://best-deals.pro/visit/filterbuy-13x21-5x1-merv-11-air-filter-4-pack)
- [Aerostar 21 1/2 x 21 1/2 x 1 Air Filter MERV 13, AC Furnace Filter, 4 Pack \| HVAC & Home, Air Conditioner & Heater Replacement, Actual Size \(21 1/2 x 21 1/2 x 3/4\), MPR 1500/FPR 10, Made in USA](https://best-deals.pro/visit/filterbuy-13x21-5x1-merv-11-air-filter-4-pack)
- [Filterbuy 17x22x1 Air Filter MERV 13 Smoke & Allergy Defense \(4-Pack\) \| Electrostatic Pleated HVAC AC Furnace Filters Replacement, Made in USA \(Actual Size: 16.50 x 21.50 x 0.75\)](https://best-deals.pro/visit/filterbuy-13x21-5x1-merv-11-air-filter-4-pack)
- [Filter King 13x21.5x1 Air Filter MERV 8, AC Furnace Filters \(6-Pack\) \| Dust & Allergy Control \(Actual Size: 13 x 21.5 x .75\)](https://best-deals.pro/visit/filterbuy-13x21-5x1-merv-11-air-filter-4-pack)
- [Filterbuy 13x21.5x1 Air Filter MERV 8 Dust & Allergy Defense \(4-Pack\) \| Electrostatic Pleated HVAC AC Furnace Filters Replacement, Made in USA \(Actual Size: 12.88 x 21.50 x 0.75\)](https://best-deals.pro/visit/filterbuy-13x21-5x1-merv-11-air-filter-4-pack)

## Add-ons

- [Aerostar Air Filter 19.875x21.5x1 MERV 13 AC Filter, Furnace Filter, 6 Pack \| ACTUAL SIZE \(19.875 x 21.50 x 0.75\) AC Filter, Furnace Filter, Allergies, Dust, Pet Dander & Smoke MERV 13 \(MPR 1500\)](https://best-deals.pro/visit/filterbuy-13x21-5x1-merv-11-air-filter-4-pack)

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