Our 21x21x5 Rheem/Ruud (PD540018) substitute filters are specifically engineered to replace the original manufacturer Rheem/Ruud 21x21x5 filters. Filter Hut's filters are MERV classified to ASHRAE 52.2 test classifications establishing that our air filters will capture particulate as good or better than the name brand part number (PD540018) air filter. Our filters also come in Odor Ban odor isolating carbon-inlayed media. *Company names are listed for filter substitution 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: PD540018.
- Envaero brand by Accumulair.
- Designed to replace the original manufacturer filter.
- Filters framed and preassembled for ease of intallation. (Non-expandable, no end caps needed, etc.)
MERV classified to ASHRAE grades.
- Available with Odor Ban odor isolating carbon-inlayed technology.
- 2 filters per case.