Have you executed tunnel or metro ventilation projects before?
Not yet — this is an engineered-capability page, and we will not claim a tunnel reference we do not have. What is proven is the underlying fan engineering across our range: large-diameter impellers, high-volume ventilation duty, high-temperature construction to 600 °C, and reversible airflow. We engineer each tunnel or metro fan to your stated flow, static pressure, rated smoke temperature and emergency period, and we prove the design on our test rig before dispatch. Tell us your duty and your emergency case and we engineer to it.
What smoke temperature and duration can the emergency fans handle?
We build to the rated emergency duty you specify. Tunnel smoke fans are typically rated for 250 to 400 °C over a 60 to 120 minute emergency period, and our envelope ceiling is 600 °C continuous, so the rated smoke duty sits inside what we engineer. Above about 350 °C we fit a shaft cooling disc to keep heat off the bearings, keep the bearings outside the airstream, and add expansion joints for the thermal growth. The wheel and shaft are sized for stress at temperature, not just cold, so the fan holds its rated flow through the emergency instead of distorting or stalling. We build to your stated temperature-time rating, not a generic figure.
Can the fan run supply one way and extract smoke the other?
Yes. Reversible airflow is a design case we engineer to, because most tunnel smoke strategies flip the ventilation direction on a fire — the fan that supplies clean air must extract smoke the other way, and often restart against a hot moving air column already in the bore. We engineer the impeller and drive so the fan makes its rated flow in both directions and can restart hot, and we prove the reversal case on the test rig before dispatch, not on the day of the incident.
How do you keep a large tunnel fan quiet and efficient for the everyday duty?
The emergency runs for minutes; the ventilation runs for decades, so we size the everyday operating point onto the best-efficiency region of the selected wheel — an aerofoil or backward-curved plate wheel for clean high-volume air — rather than tuning only to survive the fire. A fan running 5 percent off its best efficiency burns that gap in power every hour for the life of the tunnel, so best-efficiency selection is the energy story. We add inlet and outlet silencer scope and choose blade geometry to hold your site sound limit, and specify the whole scope on the GA drawing you sign off.
Can you build a replacement to match our existing tunnel or car-park fan?
Yes. We reverse-engineer to the existing duty point (flow, static pressure, rated smoke temperature and emergency period), bearing centres, inlet/outlet orientation and foundation bolt pattern so the unit drops onto the existing base and ducting — whether it is a jet fan, a shaft supply or exhaust fan, a car-park extract fan or an emergency smoke fan. Made to your installation and your emergency rating, not a nearest-catalogue substitute. Send the old GA, the nameplate and the emergency rating and we match it.
Do you performance-test the fans, and what about AMCA, CE, ATEX and quality certification?
Every fan is performance-tested in-house to the AMCA 210 / ISO 5801 method on our 200 HP VFD test rig, and dynamically balanced to ISO 21940 G6.3 as standard (G2.5 / G1.0 on application). To be precise: that in-house testing is to the AMCA 210 / ISO 5801 method, not AMCA-certified, and we are not an AMCA member; CE is self-declared per 2006/42/EC and 2014/35/EU, and ATEX Zone 2/22 is self-declared per 2014/34/EU (Category 3) where the area classification calls for it — those are self-declarations of conformity, not third-party certifications. Our only third-party certification is ISO 9001:2015.
