Car park ventilation:
Smoke control for car parks

Car park ventilation at Paradise Street, Liverpool

Enclosed or underground car parks need smoke clearance or smoke control ventilation to assist fire-fighting operations. Such systems are often combined with fume ventilation to prevent the build-up of vehicle exhaust gases in normal day to day use of the car park.

View our Car Park Ventilation leaflet for further information regarding the design approaches.

Jet fans, impulse ventilation, induction ventilation

Colt offers the latest technology in impulse or induction ventilation systems. Over the past ten or so years, the strategy for ventilating underground car parks has changed dramatically. Traditional ducted systems have been replaced by so-called ‘jet fan’, ‘impulse’ and/or ‘induction’ systems. These use relatively small fan units positioned around the car park to direct the smoke towards the extract points.

As a result, the need for distribution ductwork throughout the car park is eliminated. This may save car-parking spaces and make the car park a lighter, less cluttered environment.

Colt offer Jetstream impulse fans and Cyclone induction fans specifically for this purpose.

Features and benefits of impulse and induction systems compared to traditional ducted systems:

  • Easier and quicker installation
  • Lower excavation costs
  • Lower maintenance
  • Cleaner, less cluttered ceilings

Colt car park ventilation testing

In 2004 Colt carried out comparative full-scale tests in an underground car park in Bristol. The purpose of the Bristol car park ventilation tests (3 MB PDF) was to demonstrate that the impulse and induction systems can provide an equivalent performance to traditional ducted systems.

The tests showed that there was in fact a significant improvement in the time taken to clear the car park of smoke when using the new systems compared with traditional ducted systems.

In 2005 Colt and the Building Research Establishment (BRE) carried out a series of full-scale hot smoke tests (0.5 MB PDF), not only to demonstrate how well impulse systems can control the flow of smoke in a car park, but also to confirm the effectiveness of the computational fluid dynamics (CFD) modelling approach used by Colt. These tests included setting up a 35m x 30m x 3m test rig and setting light to a car shell containing a tray of diesel fuel to create a 1 MW fire size.

The results of the tests clearly indicated that impulse systems are capable of controlling the spread of smoke from a car fire and keeping significant areas of a car park effectively smoke free. BRE confirmed that: "The smoke movement during the fire with the impulse fans running was as predicted by the CFD modelling Colt had carried out before the tests." Read the Middlesborough smoke tests news story.

Further reading

Please see our Car Park Ventilation leaflet (4 MB) for further details relating to:

  • Legislation and standards
  • Design approaches
  • Features and benefits of impulse systems
  • Extract systems
  • Controls
  • CFD

Next steps

Contact Colt. We have considerable experience in the design and implementation of smoke control systems or smoke ventilation in car parks.

All our systems are specifically designed to blend into the building structure, and where possible are concealed until needed. They are compliant with all relevant codes and standards.

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