Newsheet 6

Multi-Storey Car Parks - Fire Detection Systems

Other Fire Protection & Heat Detection Newsheets

Although it would be accurate to say that each application for LINEAR HEAT DETECTION is, in its own way, " unique", some risks may seem more "unique" than others!

MULTI-STOREY CAR PARKS have repeatedly presented consultants, fire engineers and end users with many practical considerations - other than purely just specifying what are generically believed to be the most sensitive fire detection systems.

Car parks are in general, a much more "open area" risk protection consideration - therefore more susceptible to external environmental influences that could adversely affect many point type fire detectors response capabilities. The high airflows and vehicle exhaust fumes experienced in such areas, severely restrict detector selection options. Add to this the possible high ceilings and increased risk of vandalism (both to the parked vehicles AND installed detectors) and detector selection options are further reduced!

In some cases, " line of sight" detection (typically beam detection) has been selected. However, the construction of the car park ceiling / roof frequently employs large support beams - which will reduce the effectiveness of beam type detection. So what should be specified and installed? …..

Lets consider the risks..a localised fire outbreak, normally central to heavily populated shopping malls, airports, hospitals, hotels etc. Where the environmental conditions local to the detector are going to be polluted by exhaust fumes. Where, (locally again) high airflows exist - so the detector should be able to operate rapidly, with the minimum of costly maintenance, without false alarms, and be flexible enough in its construction so as to allow its installation close to the origin of the fire - therefore providing economical, fast, effective and efficient detection. It should be aesthetically acceptable, but not "invite" attention and potential mechanical damage - through its prime location at ceiling height and its instantly recognisable detector appearance (often white in colour) - from the inevitable groups of vandals that can be found regularly within such areas (even within security patrolled car parks) - regardless of Country or culture.

The detector must be able to withstand corrosive environmental conditions - possibly even the "attention" of hungry rodents - but most of all it MUST be able to efficiently and effectively protect both human life and capital investment.

PROLINE LINEAR HEAT DETECTION meets all the above design, installation and operating criteria required for MULTI-STOREY CAR PARKS.

As a cable and detector in one, the wide range of linear heat detection systems offered by PROLINE LINEAR DETECTION provide TOTAL area coverage - not just localised point sensitivity. They can be cost effectively and rapidly installed at regular intervals across the underside of the roof / ceiling (using "T" type clips to ensure a clear air flow around the heat sensitive cable, and therefore eliminate loss of system sensitivity from heat absorbent surfaces). The maximum distance between parallel runs across the roof / ceiling should be 10.6m/35feet -UL listed -all alarm temperature ratings, or 9.0m/30feet (TH68 &TH88) or 7.5m/25 feet (TH105)- F.M. Approved - with the runs closest to the outside walls being not greater than 50% of this distance from the walls. IN ADDITION, the sensor cables can also be regularly directed in a vertical mode from roof / ceiling height to floor level (and back to roof / ceiling height) by using the concrete roof support beams of the car park construction - thus bringing the detection capability to the local heat source and thereby ensuring detection is NOT restricted only to high level!

The corrosion resistant external extrusion of the heat sensitive cable, has repeatedly proven its ability to withstand rodent attack and other physical abuse (including direct repeated impact, manually applied by a heavy device - such as a "hammer") far beyond levels one would expect from a 4mm diameter cable! Added to which the colour of the same outer extrusion (black or dark grey - depending on product selection) allows the detector to rapidly "blend" in with the background. Not instantly obvious (only to those that should be made aware) that it is a detection system!

In the event of mechanical damage, an open circuit fault condition will be signalled. After detection of a fire condition - only sectionalised replacement is necessary. Without the requirement for specialist tooling or training.

The sensor cable can be DIRECTLY integrated with a central fire alarm control panel (supplied by others), without the need for any dedicated interface unit provided the following criteria is met by the control panel:-

It will detect and signal open circuit FAULT, short circuit FIRE conditions on the sensor (and any interconnecting) cable
It is capable of working with a maximum of 650 ohms / km electrical resistance connected to its zone card (the sensor cable resistance)

Alternatively, a linear detection interface unit MAY be specified and supplied, which increases the system integration, signalling and annunciation capabilities by way of: -

An alarm point location meter (the visual indication of EXACTLY where along the sensor cable length the alarm condition is being signalled).
FIRE and FAULT relay contact outputs.
4-20 ma outputs
0-5v outputs.

For additional information, assistance, pricing and system supply, contact us.