Commercial HVAC Restoration Kilmer USPS Hub

We mobilized a four-person NADCA-certified crew to execute a top-to-bottom decontamination of the USPS distribution hub, approximately 410,000 sq ft complex that was already in the middle of a major HVAC restoration. Pre-clean borescope footage and manometer readings confirmed dense particulate loading across all four processing levels, especially in the main trunks feeding the sortation floor and mailroom mezzanines. Working after hours to avoid interrupting postal operations, we broke the network into 12 sections, set HEPA-filtered negative-air machines at each air handler, and used rotary cable whips, skipper balls, and soft-brush agitation to dislodge buildup from the 37 VAV boxes, reheat coils, and branch runs. Every diffuser and grille was removed, washed, and sanitized; drip pans and condensate lines were flushed and treated with EPA-registered biocide. Post-clean differential pressure dropped by 0.3–0.5 in. w.c., airflow at the farthest registers increased by 18%, and IAQ sampling showed particulate counts back within ASHRAE specs—all while keeping the postal facility fully operational.