Corrosion-Resistant Exhaust for a Working Research Lab

When a mechanical engineer stamps a lab exhaust drawing, “corrosion resistance” isn’t a nice-to-have line item — it’s a requirement checked component by component. That was the case on a recent tenant-improvement project for a research and analytical lab in Richmond, BC, referred to here as the Kemetco Lab project.

The Challenge

The lab’s fume hoods each ran dedicated exhaust up to rooftop fans, and the mechanical engineer wasn’t leaving corrosion resistance to chance anywhere along that path. The stamped review comments for fan tags EF-5, 7, and 8 covered the usual ground — discharge velocity, controller location — but they went further, stating directly that components in the exhaust airstream needed corrosion resistance, not just the ductwork feeding them.

That distinction mattered because the ductwork itself was already built to a demanding standard: seam-welded, gas-tight construction, pressure-tested for leaks under negative pressure. Whatever sat at the end of each run had to hold up to the same corrosive exposure, with no coating to maintain and no weld seam to worry about.

The Solution

Plastec supplied five V35 Velocity Series centrifugal blowers, one per exhaust branch, built entirely in polypropylene. Each unit is a 2 HP, 870 RPM, 208–230V three-phase blower rated for up to 3,730 CFM at up to 1.4 in. wg of static pressure — well above the roughly 3,000 CFM at 1.0 in. wg the branches are designed to move — with the discharge nozzle sized to maintain the minimum 3,000 FPM exit velocity the engineer’s design called for.

Because the mechanical contractor was still finalizing drive controls, Plastec shipped each blower control-ready: a wired-breaker enclosure in place, with space reserved for VFDs to be sourced and installed separately. That kept fan selection and the controls decision on two independent timelines instead of forcing one to wait on the other. Motorized backdraft dampers and spring isolators rounded out the package, addressing both airflow control and vibration — these units sit directly over occupied lab space.

The Result

Five fume hood exhaust branches, five corrosion-resistant blowers, matched to a design that didn’t leave room for a weak link. No coatings to inspect for wear, no seams to track for early failure — just a polypropylene blower built for the same chemical exposure the ductwork around it was engineered to handle.

It’s a straightforward example of what corrosion-resistant ventilation is supposed to solve: not a spec-sheet checkbox, but the actual chemistry moving through the system, from the fume hood to the roofline.