Description
This air filter is made to a 38-3/8 x 31-3/8 x 1″ nominal size for HVAC systems, air handlers, and return grilles that require an exact custom dimension rather than a standard retail size.
Filter bypass — air slipping past a loose frame instead of through the pleats — is one of the most common reasons a filter underperforms its MERV rating in the real world. A precise fit closes that gap.
MERV 13 targets the fine particulate fraction that lower MERV ratings allow through — including smoke, bacteria-carrying dust, and combustion byproducts. Airflow resistance is higher than MERV 8 or 11, so systems with borderline static pressure should be evaluated before switching up.
Specifications
- Nominal size: 38-3/8 x 31-3/8 x 1″
- Actual dimensions: 38-3/8 x 31-3/8 x 3/4″
- Efficiency rating: MERV 13
- Quantity: 12 filters per carton
Common applications for a 38-3/8 x 31-3/8 x 1″ custom filter include retrofit installations, legacy HVAC systems installed before standard sizes were codified, built-in return grilles that were framed to non-standard dimensions, and commercial unit housings that don’t match any current off-the-shelf size.
Features
- Replace approximately every 90 days in standard installations; shorter intervals in high-dust, smoky, or heavy-use environments
- Suitable for forced-air furnaces, central AC, heat pumps, and packaged HVAC systems
- Sold as a 12-pack so you have a full year of replacements on hand
- Cardboard frame with reinforced media for structural stability during handling and installation
Same 38-3/8 x 31-3/8 x 1″ size, different efficiency rating
| MERV 1-4Basic dust-stop | MERV 8Standard efficiency | MERV 11Enhanced efficiency |
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Need 38-3/8 x 31-3/8 x 2″ or another depth? This size is available in other depths we don’t stock online — reach out and our team will quote it for you, typically same business day.
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