GSH Maintenance Team Overhauls Critical AHU Vibration Springs
Deep beneath the laboratories and animal facilities of the National Institutes of Health in Baltimore, a dedicated crew keeps the air flowing reliably — day in, day out.
Right now, the GSH maintenance team is in the middle of a major project: replacing the massive vibration-isolation springs on air handling units that serve the NIA and NIDA vivariums. These are no ordinary AHUs. Each one pulls 100% outside air, cools it across chilled-water coils, and delivers over 30,000 CFM to sensitive animal holding rooms and research labs.
At the heart of each unit sits a single 125 hp motor driving a Twin City fan — a combined assembly weighing almost 6 tons. The only thing keeping that mass from shaking the building apart? Four heavy-duty coil springs that had been on duty for nearly 20 years. After two decades of humid Baltimore summers, condensate dripping from the cooling coils had migrated into the motor compartments. The result: springs that looked more like rust fossils than precision components.
Decades of condensate exposure turned solid steel into rust; almost no original metal remains – just rust flakes.
The GSH team, often working in the tightest spaces, has been tackling these units one by one.
Phil Heim, Assistant Chief Engineer, cutting free rust-locked components.
Removing the springs for a 6-ton motor/fan assembly in a cramped air handling unit requires rigging, jacks, grinding, torches, and decades of collective experience.
Some springs literally crumbled upon removal. Replaced with springs fresh, powder-coated, and ready for the next 20+ years.
Alongside the replacement, GSH redesigns drainage paths to prevent condensate from reaching the spring mounts. This isa proactive upgrade that significantly extends the lifespan of the new components.
Before: on the edge of failure. After: smooth, quiet, and built to last.
The project remains ongoing, with three additional Air Handling Units still scheduled for the same treatment. That means more heavy lifts and sparks in the dark—all to ensure research animals and vivarium staff remain comfortable. Meanwhile, keeping the laboratories operating so they never miss a breath of perfectly conditioned air. The next time everything in a critical NIH facility simply works, remember the GSH maintenance team. Nonetheless, the professionals who wrestle rust, gravity, and six‑ton assemblies so vital science continues without interruption.
See how GSH keeps mission‑critical environments operating safely and reliably. Connect with our team to learn how proactive maintenance and technical expertise protect your most critical assets.