The effect of sprinklers in parking garages

Cegelec Fire Solutions Belgium (CFS), in collaboration with Fire Engineered Solutions Ghent (FESG), has initiated a study of fire safety in underground car parks. In January 2018, a new stricter Flemish directive took effect for the fire protection of car parks. The two parties wanted to demonstrate several alternatives in an innovative way.

On the Vesta Campus in Ranst, CFS has simulated a parking garage by welding containers together. Employees of Actemium were brought in to install various measuring instruments in the containers, so that the pressure, temperature and wind speed, among other things, could be measured during the various tests. In recent months, three cars have been put in the containers for each test, and the central car has been set on fire in a controlled way. The sprinkler configuration protecting the cars as well as the pressure and the flow rate were changed, so that the heat released by the fire could be determined and the best adjustment of the sprinklers could be comprehensively studied.

The aim of this test setup was to analyse the effect of sprinklers on burning cars in an underground parking garage. In tests without a SHEV (smoke and heat exhaust ventilation system) or with a less powerful SHEV, the fire never spread to the other two cars. The sprinklers were able to fight the fire very effectively and the fire brigade could safely finish extinguishing it manually. With a SHEV according to the current standard, the fire did spread.

The result of these fire tests, together with a substantiated risk analysis tool, gives an accurate picture of the safety level and the fire safety in underground car parks.

Dominique Goidts (Business Unit Manager, Cegelec Fire Solutions Belgium): “Thanks to the simulation we can study the fire behaviour of cars, the probability of fire spreading between the different cars and the effect of different sprinkler configurations. In addition, we measure the effect of the sprinklers on the smoke gas temperature and radiation fluxes. We monitor the influence of different set ventilation speeds and the effect of smoke propagation against this ventilation direction. Finally, we study what the different consequences can be for a safe intervention by the fire brigade.

WHAT DOES THIS NEW DIRECTIVE INVOLVE?

Since 1 January 2018, new legal requirements have been in effect in Flanders with regard to fire safety in underground garages. An important factor in this is the combined use of both smoke and heat exhaust (SHEV) and sprinkler systems. “Until the end of 2017 there was only a regulation in Belgium for underground parking garages with an area greater than 2500 m², where the builder had the choice of providing either a SHEV or sprinklers,” says Dominique Goidts. “Since 1 January 2018, this directive also holds for car parks larger than 250 m². And for car parks larger than 10,000 m² the builder is required to install a SHEV installation combined with sprinklers.”

Although the new requirements imposed by the government are stricter, they also open up new prospects, as they allow a choice between different systems. “For smaller car parks, a sprinkler installation connected to the public water system seems to be a very reliable solution. Such installations are relatively low-maintenance. On the other hand, for larger parking garages with sprinklers, the SHEV system can be dimensioned more efficiently, which leads to smaller ducts, fewer smoke screens and less maintenance,” says Xavier Deckers of FESG.