Electric vehicles are becoming a more familiar sight in car parks, and charging points are appearing in everything from shopping centres to residential developments. But as the mix of vehicles changes, does car park fire detection need to change too?
Petrol and diesel vehicles have always presented a fire risk. EVs haven’t replaced those concerns, but they have introduced another type of fire that building owners and operators need to understand. In particular, lithium-ion battery fires can be difficult to manage, especially in enclosed spaces where access is restricted.
How are car park fire detection risks changing?
Vehicle fires aren’t a new problem. Petrol, diesel, electrical faults and combustible materials have long been part of the risk assessment for car parks. What has changed is the growing number of vehicles powered by lithium-ion batteries, alongside the infrastructure needed to charge them.
Installing EV charging points can mean additional electrical equipment, cabling and connections throughout a car park. These need to be properly designed, installed and maintained, just like any other electrical installation.
The location of the car park also makes a difference. In an open-air facility, smoke and heat can disperse more freely. Underground and enclosed car parks present a different challenge, with restricted access, ventilation requirements and potentially difficult conditions for emergency responders.
What makes EV fires different?
The main concern with lithium-ion batteries is thermal runaway. This occurs when a battery cell begins to generate heat through a self-sustaining chemical reaction. That heat can affect neighbouring cells, allowing the problem to spread through the battery pack.
Once thermal runaway develops into a fire, dealing with it can be difficult. Battery fires may require prolonged cooling, and firefighters may need to monitor the vehicle for further heating or reignition after the initial incident.
These problems are particularly relevant in underground car parks, where getting close to the affected vehicle may be difficult and smoke can make conditions worse.
That doesn’t mean EVs are necessarily more likely to catch fire than petrol or diesel vehicles. Fire frequency and fire behaviour are two different questions. For car park operators, the practical issue is being prepared for the types of incidents that could occur, rather than focusing on one vehicle technology alone.
Why is early car park fire detection important?
A fire in a large car park can be difficult to locate quickly. Vehicles may be parked across several levels, with long distances between different areas of the building. If an incident starts away from occupied spaces or staff, it may not be immediately obvious where the problem is.
Finding the source early matters. The sooner operators know something is wrong, the sooner they can investigate, activate the relevant procedures and provide emergency responders with useful information.
Location is particularly important. Knowing which level or section of a car park is affected is far more useful than receiving a general alarm with little indication of where to look. It can help responders reach the right area sooner, when conditions allow.
The difficulty is that car parks aren’t always straightforward environments for fire detection. Air movement, vehicle exhaust, dust and the sheer size of the space can all influence which technologies are suitable. Detection therefore needs to be designed around the building and its fire strategy, rather than treated as a standard installation that works the same way everywhere.
How can fiber optic linear heat detection help?
Fiber optic linear heat detection takes a different approach from systems that rely on individual detectors positioned around a space.
A sensing cable is installed along the areas that need protection, with temperature measured continuously along its length. This gives operators information about conditions across the cable route, including where an unusual increase in temperature is occurring.
Bandweaver’s FireLaser system uses this approach to monitor large areas and identify abnormal thermal activity. Its RapidScan intelligent alarm technology goes beyond checking whether a fixed temperature has been reached. It can also recognise unusually rapid temperature increases and localised hotspots.
That distinction can be useful in a car park. A developing heat source may produce an unusual temperature change before the surrounding area reaches a conventional fixed alarm threshold. Where the sensing cable is appropriately positioned, recognising that change can provide an earlier warning.
The sensing cable itself contains no powered sensors or electronics along its length, reducing the number of field devices that need maintaining. And because the system measures temperature rather than relying on airborne smoke reaching a detector, dust, fumes and other particulates don’t affect the sensing principle in the same way they can affect smoke detection.
As with any detection technology, cable positioning and system design are critical. FireLaser monitors the conditions along its installed sensing route; it doesn’t measure the temperature inside an EV battery or guarantee detection before a battery fire begins.
Preparing car parks for the future
The growing number of EVs is a good reason for car park owners and operators to revisit their fire risk assessments, particularly when adding charging infrastructure or making changes to an existing facility.
There’s no single detection arrangement that will suit every car park. A small open-air site has different requirements from a large underground facility beneath a residential building. The layout, ventilation, access arrangements and wider fire protection systems all need to be considered.
Early warning and accurate location information are key. If a fire does occur, operators need to know where it is and have a clear process for responding.
However, early detection is only a small part of the bigger picture. While raising the alarm quickly is essential for life safety and evacuation, limiting damage to vehicles and the building also depends on having appropriate fire suppression measures in place.
The most effective solution is one that uses fire detection and suppression systems working together. Utilising early detection to inform an automated suppression system allows the affected area to be dealt with sooner, controlling a developing fire and reducing the damage caused. When systems are designed to work together, accurate location information can enhance this, allowing suppression to be focused on the areas it’s needed most.
For larger facilities, fiber optic LHD can be part of that approach, providing continuous temperature monitoring and location information without the need for powered sensors along the cable route.
Find out more about Bandweaver’s FireLaser linear heat detection system, or contact us to discuss becoming a Bandweaver distribution partner.