Field notes on FRP air-handling: what’s changing with fans, dampers and demisters

If you work around scrubbers, odor-control rooms, or chlorine emergency lines, you already know the gear that quietly keeps everyone safe. I’ve been touring plants where Fans & Dampers & Demisters made from fiberglass (FRP) are replacing legacy metal hardware. Why? Corrosion, uptime, and—surprisingly—noise. People want less of all three.

What’s trending in 2025

• Shift to FRP vinyl-ester systems for acid/alkali duty in wastewater and chemical processing.
• Higher efficiency backward-curved fans with AMCA-verified curves—people want their power bills down.
• Demister upgrades to reduce visible plume and carryover; facility neighbors complain quicker these days.
• Tighter leakage specs for isolation dampers in emergency chlorine scrubber influent ducts.

Typical specifications (condensed)

Manufacturing process in a nutshell: corrosion barrier layup (2× C-glass veil), structural mats with ECR glass, hand lay-up or vacuum infusion for housings, filament winding for round shells, post-cure, then AMCA 210 fan curve verification and AMCA 300 sound tests where applicable. Chemical resistance screening per ASTM C581 and laminate QA per ASME RTP-1. I like to see spark testing on linings and hydrostatic leak checks on housings—saves headaches later.

Vendor snapshot (real-world buying concerns)

Where they’re used (and what people report)

• Municipal odor-control skids: operators say the FRP housings “just don’t pit like the old ones.”
• Emergency chlorine scrubber influent ducts: tight shutoff dampers reduce standby leakage anxiety.
• Fume scrubbers/strippers in battery plants and pulp & paper: demisters cut visible plume; neighbors calm down.
• Waste treatment and alkali neutralization lines: less maintenance, fewer Saturday callouts.

Case notes and test data

A mid-size WWTP retrofitted Fans & Dampers & Demisters on biofilter trains: fan brake horsepower dropped ≈12% after a wheel redesign; demister carryover measured <0.01 mL/m³ with 99% removal at ≥5 μm droplets; isolation damper leakage tested to Class 1A at 300 Pa. Another chemical site reports two-year inspection showing intact corrosion barrier (no blush), which—honestly—is what you want to see.

Customization and logistics

Options include resin systems (VE, bis-A VE, novolac), PP/PVDF liners, seismic bases, ATEX/IECEx motors, sound packages, and removable demister cassettes. Flanges per ANSI 150/DIN PN10. Origin: No. 1289, Yingbin South Street, Jizhou District, Hengshui, Hebei, China. Lead time is typically 4–8 weeks, and yes, factory FAT with AMCA 210 curves is available on request.

Why FRP here?

Lower corrosion, lighter installs, and stable performance under acid gas exposure. For teams juggling uptime and compliance, Fans & Dampers & Demisters in FRP are, frankly, the pragmatic choice.

1. AMCA 210: Laboratory Methods of Testing Fans for Certified Aerodynamic Performance Rating. https://www.amca.org
2. AMCA 300: Reverberant Room Method for Sound Testing of Fans. https://www.amca.org
3. AMCA 500-D: Laboratory Methods of Testing Dampers. https://www.amca.org
4. ASTM C581: Standard Practice for Determining Chemical Resistance of FRP. https://www.astm.org
5. ASME RTP-1: Reinforced Thermoset Plastic Corrosion-Resistant Equipment. https://www.asme.org
6. ISO 9001/14001 Quality and Environmental Management Systems. https://www.iso.org