Axial Flow Fan for Tunnel Ventilation — Manufacturer & Supplier
Vayuvents Pvt. Ltd. manufactures and supplies heavy-duty axial flow jet fans for tunnel ventilation — including road tunnel CO dilution, railway tunnel heat and smoke exhaust, metro tunnel emergency ventilation, and utility tunnel fresh air supply.
Road and railway tunnels create enclosed environments where vehicle exhaust gases, combustion products, and heat rapidly accumulate without forced ventilation. In India's rapidly expanding road and metro tunnel network including NHAI highway tunnels and metro projects — engineered tunnel ventilation is a mandatory safety requirement.
Jet fans are the standard solution for longitudinal tunnel ventilation. Suspended from the tunnel ceiling, they create a high-velocity air jet that entrains a much larger volume of tunnel air — creating longitudinal airflow that pushes pollutants from traffic entry to the exit portal without requiring ductwork.
For emergency smoke extraction, reversible jet fans can reverse airflow direction to create a tenable environment upstream of a fire for evacuation. Vayuvents supplies both standard and fire-rated tunnel jet fans for normal ventilation and emergency smoke extraction duty.
How It Works in This Application
Traffic Entry Zone
Vehicle exhaust from traffic entering the tunnel generates CO, NOx, and particulates that must be diluted and exhausted before reaching hazardous levels.
Jet Fan Entrainment
Ceiling-mounted jet fans discharge a high-velocity air jet that entrains surrounding tunnel air, creating longitudinal airflow from entry to exit portal.
Pollutant Dilution and Transport
The longitudinal airflow dilutes vehicle exhaust and carries pollutants toward the exit portal, maintaining CO and visibility levels within safe limits.
Emergency Smoke Mode
On fire detection, reversible jet fans operate in smoke extraction mode, directing smoke toward the downstream portal while maintaining fresh air upstream.
Recommended Variants
Reversible Jet Fan
Bidirectional operation for both normal longitudinal ventilation and emergency smoke extraction — standard for road tunnels.
Most RecommendedFire-Rated Jet Fan
F400 or F600 fire-rated jet fans for operation at 400 or 600 degrees Celsius for 120 minutes during tunnel fires.
Tube Axial Tunnel Fan
Large-diameter axial fans for transverse tunnel ventilation systems with supply and exhaust ductwork.
VFD-Controlled Jet Fan
Variable speed jet fans for energy-optimised tunnel ventilation matched to real-time traffic and pollutant measurements.
Technical Specifications
| Parameter | Specification |
|---|---|
| Airflow Capacity | 15,000 to 1,00,000 m3/hr per fan |
| Jet Thrust | 100 to 2,000 N |
| Outlet Velocity | 20 to 34 m/s |
| Motor Power | 5.5 to 90 kW |
| Fan Diameter | 630 to 1,800 mm |
| Fire Rating | F400 / F600 120 min on request |
| Standards | IS 4894, IRC SP-91, EN 12101-3 on request |
Key Features
- Reversible operation provides both normal ventilation and emergency smoke extraction from a single fan unit
- Fire-rated variants maintain operation at 400 or 600 degrees Celsius for 120 minutes for emergency scenarios
- Silencer sections available at both inlet and outlet to reduce noise in occupied tunnel environments
- VFD-compatible for traffic-responsive ventilation control reducing energy during low-traffic periods
- Stainless steel impeller and casing options for tunnels passing through aggressive groundwater environments
- Suspension bracket system designed for ceiling mounting within tunnel crown clearance constraints
- Control panel and SCADA integration for remote operation from tunnel control room
- Works performance test with measured airflow data and thrust measurement certificate
Industries That Use This Application
Road Tunnels
National highway tunnels under NHAI, state PWD, and expressway authorities
Railway Tunnels
Indian Railways and private freight railway tunnel ventilation
Metro Tunnels
Urban metro rail tunnel ventilation and emergency smoke management
Under-River Tunnels
Immersed tube and bored tunnels under rivers in major Indian cities
Cable Tunnels
Power cable and utility tunnel fresh air supply and heat exhaust
Mountain Tunnels
High-altitude highway tunnels with long lengths and high traffic
Urban Underpasses
City road underpasses with CO accumulation from traffic congestion
EPC Contractors
Tunnel construction contractors requiring temporary and permanent ventilation
✓ Supply & Support: Vayuvents manufactures tunnel jet fans at our Vasai, Mumbai works. We provide jet fan selection based on tunnel geometry, traffic volume, CO design concentration, and emergency smoke scenarios. Complete supply with suspension brackets, silencers, and control panels is available.
FAQs
A jet fan is a high-velocity axial fan suspended from the tunnel ceiling that discharges a high-speed air jet along the tunnel axis. This jet entrains a much larger volume of surrounding tunnel air — typically 10 to 20 times the fan airflow — creating longitudinal airflow that carries pollutants toward the exit portal without requiring full-length ductwork.
A reversible jet fan can operate in both forward and reverse airflow directions. In normal operation all fans blow in the same direction matching traffic flow. In a fire emergency fans on the fire side reverse to create a fresh air zone upstream of the fire and push smoke toward the downstream portal.
Tunnel ventilation fans near or above the fire design point require F400 or F600 fire rating — meaning they continue to operate at 400 or 600 degrees Celsius for 120 minutes, allowing evacuation and fire brigade intervention.
The number depends on tunnel length, cross-section area, design traffic volume, and CO design concentration. For a typical 1 km two-lane bidirectional tunnel, 6 to 10 jet fans of 45 kW each are typically required. Vayuvents provides sizing calculations based on IRC SP-91 methodology.
Yes. Vayuvents supplies axial fans for metro rail tunnel ventilation including shaft fans, underplatform exhaust fans, and over-track exhaust fans in addition to jet fans.
Yes. Vayuvents provides jet fan commissioning including thrust measurement and airflow verification at site. Works acceptance tests with calibrated thrust measurement are available for critical tunnel projects.
Contact Vayuvents at enquiry@vayuvents.com or call +91 90961 88703. Share your tunnel geometry, design traffic volume, CO design limit, and fire safety requirements. We will provide a jet fan selection and commercial proposal within 48 hours.
