Make-up air. The documented stage is the Viledon F45A 1/1 pocket filter at 24" x 24" x 26", available by the two-pack (SKU 000-140) or single (SKU 000-141), plus the four-pocket 36" x 48" x 18" bag unit (SKU 000-230). Pocket filters fail politely, losing airflow gradually rather than collapsing, so watch AMU pressure rise and change them before the booth starts running lean on make-up air.

Intake ceiling. Seven panels across the plenum. The documented matches are the 38.5" x 108" polyester ceiling pad (SKU 700-229) and PA 560 G-10 pads at the 39" x 108" nominal trim (SKUs 560-390 four-pack and 560-400 three-pack). The half-inch spread is nominal-versus-trimmed catalog sizing within one slot family; check one frame before you standardize.

Exhaust floor. The Blackhawk exhausts downward, and the documented media is 22 gram fiberglass arrestor cut from roll stock, with the extra-heavy-duty 36" x 100' roll (SKU 200-080) the cataloged match. Cut a complete grid set per change. Roll media on a floor grid is economical, but only if the cut pads actually fill the openings; gaps at the grid edges are unfiltered exhaust.

Cycle math. Three stages, three cadences: pockets by pressure rise, the ceiling on a fixed set schedule, and the floor rolls by loading, which spray volume drives.

A Blackhawk spraying automotive refinish coatings sits under EPA 6H: filtered booth, maintained per specification, documented changes. OSHA 1910.94(c) requires the ventilation system to keep doing its job during spray operations, and on a downdraft the floor arrestor is the component that quietly erodes compliance as it blinds. NFPA 33 adds the fire-protection lens: captured overspray in floor media and residue in the exhaust plenum are combustible deposits to be changed out and disposed of properly, not accumulated. A change log that lists pockets, panels, and floor media on dated lines is the audit answer for all three.