These 21x21x5 Rheem/Ruud (Protech 540018) style air filters are specifically engineered to substitue for the name brand Rheem/Ruud 21x21x5 filters. Our filters are MERV rated to ASHRAE 52.2 test ratings ensuring that our air filters will capture dust as good or better than the original brand part number (Protech 540018) air filter. Our air filters can be selected with Odor Ban odor filtrating carbon-inlayed material. *Name brands are used for air filter style identification purposes only.
- 21 x 21 x 4. 5 nominal size.
- 20-3/4 x 20-3/4 x 4-3/8 actual size.
- Replaces Rheem/Ruud brand 21x21x5 part number: Protech 540018.
- Envaero brand by Accumulair.
- Engineered to replace the original manufacturer filter.
- Filters framed and preassembled for ease of intallation. (No need for extra combs, end-caps, etc.)
MERV rated to ASHRAE classifications.
- Available in Odor Ban odor capturing carbon-infused properties.
- 2 air filters per case.