Engineered for high static pressure overcoming, dual-purpose fire safety, and acoustic attenuation across commercial, municipal, and industrial envelopes.
A transition from basic air exchange towards precision aerodynamics, variable-air-volume (VAV) pressure tracking, and life-safety dual operation.
Modern duct configurations demand inline blowers that balance the high CFM capability of axial impellers with the high static pressure tolerance of centrifugal wheels. Mixed-flow inline duct fans bridge this operational gap, enabling uninterrupted airflow across extended duct paths, elbows, and HEPA filter banks without aerodynamic stall or excessive wattage penalties.
With stringent international standards such as ASHRAE 90.1, EN 13779, and LEED v4 acoustic thresholds, inline duct fans are engineered inside acoustic cabinet enclosures featuring high-density perforated internal acoustic liners. By stabilizing intake turbulence and attenuating motor whine, inline cabinet fans reduce breakout sound down to industrial-leading dBA ratings.
Critical mechanical infrastructures in high-density facilities integrate emergency fire smoke extraction directly into primary ducting. Rated to withstand 280°C for at least 30 to 120 continuous minutes under high thermal stress, our dual-purpose inline units operate as daily low-RPM exhaust fans while immediately transitioning to maximum evacuation speed when triggered by fire dampers.
Based in Dezhou, Shandong—the epicentre of China's commercial ventilation cluster—Shandong Fengdun delivers integrated cost control, advanced sheet-metal tolerances, and rapid prototype turnarounds.
All duct fan housings, flanges, and fire-resistant shells are cut via multi-axis high-precision laser centers and molded through CNC punch presses. This mechanical precision guarantees zero frame deflection, airtight circular flange connections, and consistent tolerance alignment down to 0.1 mm, preventing casing leakage under high pressure heads.
Every impeller wheel undergoes dual-plane computerized dynamic balance verification complying with ISO 1940 Grade G2.5 standards. Eliminating microscopic mass imbalances suppresses harmonic vibration propagation down mechanical ducts, reduces operational strain on motor bearings, and extends overall MTBF beyond 50,000 running hours.
Unlike regional assemblers reliant on multiple tiers of third-party vendors, Fengdun manufactures commercial cooling towers, insulated stainless steel / enamel water tanks, UL/CE-grade fire dampers, and soundproof mixed-flow duct fans within one unified facility. This consolidated cluster ensures identical metallurgical certifications, matched control integration, and reduced container logistics costs.
Select equipment based on hydrodynamic design configurations, pressure thresholds, and environmental requirements.
| Fan Architecture | Static Pressure Range | Efficiency Rating | Primary Industrial Application | Key Mechanical Feature |
|---|---|---|---|---|
| Industrial Mixed Flow Inline | 250 – 1,200 Pa | Up to 82% Total Efficiency | Commercial Office Plenums, Industrial Production Lines, Underground Parking | Aerodynamic straight-through casing with diagonal blade acceleration |
| Soundproof Cabinet Duct Blower | 150 – 800 Pa | Up to 76% Total Efficiency | Hospital Cleanrooms, High-End Hotels, Recording Studios, Rooftop Plant Rooms | Double-skin acoustic casing lined with sound-absorbent rockwool core |
| Dual-Speed Smoke Extraction Axial | 300 – 1,500 Pa | Up to 85% Total Efficiency | Subway Tunnels, Highway Tubes, Atrium Roofs, Logistics Complexes | Cast aluminum / alloy aerofoil blades; high-temp Class H insulation rated to 280°C |
| Centrifugal Inline Utility Blower | 500 – 2,500 Pa | Up to 79% Total Efficiency | Chemical Laboratory Fume Hoods, Battery Manufacturing, Heavy Exhaust | Backward-curved non-overloading impeller with corrosion-proof coating |
Addressing structural trends across European, North American, Middle Eastern, and Southeast Asian mechanical engineering projects.
Global mechanical consulting firms increasingly mandate Electronically Commutated (EC) motors or standard IE3/IE4 premium efficiency motors coupled with Variable Frequency Drives (VFD). Direct-drive mixed flow duct fans with 0–10V modulation reduce power waste during partial-load conditions, satisfying strict international decarbonization mandates.
Projects across coastal zones, desalination facilities, and petrochemical processing hubs require specialized anti-corrosion treatments. In addition to standard hot-dip galvanized sheet steel, Fengdun manufactures duct housings in SUS304 and marine-grade SUS316 stainless steel, backed by fluorocarbon electrostatic spray coatings resisting severe C4/C5 corrosive environments.
Large infrastructure developers require exact 3D BIM models (.rfa / .step) for computerized clash detection in complex ceiling plenums. Furthermore, pre-shipment FAT verifications—covering complete airflow tests under AMCA 210 chambers, sound acoustic room trials according to AMCA 300, and certified high-voltage spark tests—have become standard procurement prerequisites.
Direct answers addressing fan selection, acoustic engineering, system balance, and export requirements.
Standard axial fans produce high air volumes at low resistance, but their blades stall and cavitate when confronted with the static resistance of complex duct networks, silencers, and bends. Mixed-flow inline fans utilize a unique diagonal-flow hybrid impeller. As air enters along the longitudinal axis, the conical wheel and twisted blade profile redirect the stream through a centrifugal vector, combining axial continuous intake with centrifugal radial compression. This increases the total air pressure (often exceeding 500–800 Pa) without requiring the bulky 90-degree transition casings of conventional centrifugal fans.
Our smoke extraction duct fans are engineered to operate at 280°C for up to two continuous hours. Key structural measures include: heavy-gauge galvanized or cold-rolled steel casings welded with anti-warp structural stiffeners; Class H high-temperature copper windings insulated with vacuum pressure impregnation (VPI); sealed high-temperature ball bearings lubricated with synthetic perfluoropolyether (PFPE) grease; and dedicated motor cooling chambers that isolate sensitive drive components from hot exhaust airstreams.
Yes. We regularly supply international EPC contractors and HVAC distributors worldwide. We build inline fans with specific motor configurations matching local grid demands, including 380V/400V/415V 50Hz (Asia, Middle East, Europe), 220V/440V/480V 60Hz (North America, Philippines, Saudi Arabia), and 110V/220V single-phase systems. Explosion-proof (ATEX / IECEx), dual-speed Dahlander winding, and VFD-inverter-duty motors are fully integrated upon specification.
In life-safety fire ventilation designs, the inline exhaust fan operates in tandem with mechanical fire dampers. Under normal operation, 70°C fusible-link dampers remain open for constant comfort ventilation. During an emergency fire condition, the central BMS or smoke sensor commands the inline fan to shift into emergency high-speed purge mode. If flue gas duct temperatures reach 280°C, the associated 280°C smoke fire damper triggers automatically, cutting the electrical interlock circuit to stop the fan and close the blades, containing fire spread between compartmental zones.
Each production run undergoes comprehensive mechanical checks: dynamic balancing verification reports, casing air-leakage tests, insulation resistance and dielectric withstand tests, and continuous running checks. Full technical documentation dossiers—including certified dimension drawings, performance fan curves (Volume vs. Static Pressure vs. Brake Horsepower), Certificate of Origin (CO), CE compliance certificates, and material mill test certificates (MTC)—are included with every export container.
Combining heavy-duty ventilation with cooling towers, commercial fire safety dampers, and certified industrial water tanks directly from our factory.
