Impulse JET fans — smoke extraction and car park ventilation without duct networks

Impulse JET fans are a distinct category of ventilation and smoke extraction equipment, designed specifically for underground car parks and tunnels where traditional ducted ventilation is impractical or prohibitively expensive. Instead of collecting and transporting air through ductwork, jet fans generate a high-velocity directed air jet (15–25 m/s) that entrains by induction the large air volume in the car park, creating a controlled longitudinal flow from fresh air inlets to extract points.

Why without ductwork: a 200-space car park has a floor area of 4,000–6,000 m² and a volume of 12,000–18,000 m³. A duct network to uniformly distribute air in this volume would be enormous, expensive and would consume valuable headroom. Jet fans ceiling-mounted at 15–25 m spacing replace the entire network with a few compact units — faster installation, lower cost, simpler maintenance.

Dual function: the same jet fans used for normal ventilation (maintaining CO concentration below 30 ppm) are those that, in the event of fire, direct smoke in the desired direction, away from evacuation routes and toward extract points. F300 or F400 certification to EN 12101-3 guarantees that the jet fan continues to operate and direct hot smoke throughout the evacuation — 60 or 120 minutes.

The ventilation.ro range includes Casals jet fans certified to EN 12101-3 (F300/60 and F300/120), with thrust airflows of 3,000–25,000 m³/h, with reversibility option (bi-directional), with connections for CO sensor and fire detection-alarm panel integration.

How to choose: the number and placement of jet fans is determined by CFD (Computational Fluid Dynamics) simulation or the simplified methodology from EN 13779 and EN 12101. The maximum effective range of one jet fan is 40–60 m. Contact our technical team for calculation and design of the ventilation-smoke control system for your car park.

👉 Centrifugal JET fans smoke extraction — centrifugal variant for higher thrust 👉 Smoke extract fans inside hazardous area — ducted extraction