Return Air Grille Filters
Return air grille filters sit in the grille itself rather than in a central filter rack—common in older homes, historic properties, and systems where the return air handler doesn't have a dedicated filter slot. These are typically larger (often 20x30 or 25x30) and thinner (1/2″ or 1″) than central HVAC filters.
Where They're Used
-
Older homes built before centralized filter racks were standard
-
Multiple return grilles — each grille gets its own filter
-
High ceilings & commercial — where maintenance access favors the grille location
Common Grille Sizes
20x20, 20x25, 20x30, 25x25, and 25x30 are the most common—with 1/2″ and 1″ depths. Non-standard grille openings are a great use case for our custom cut service.
MERV Considerations
Grille filters are typically available in MERV 4 through MERV 11. Higher MERV ratings can restrict airflow more significantly when applied to multiple return grilles in parallel, so verify with your HVAC tech if you're considering MERV 13 across multiple grille locations.
Vendor:AAF Flanders
MERV 8Vendor:AAF Flanders
