Fire Engineering: sensing safety - part 2.


Thomas Michael & Louis Chaumont, Fire Engineering & Intelligent Buildings

Data-driven optimised evacuations.

Read part 1. 

How can smart building technologies make our spaces safer?

It’s a question that – with an increasing number of projects optimising a smart-building strategy – we are now fully able to explore.

Much of the sensing technology, algorithms, and automated workflows already being deployed within buildings give us insight into building occupancy and people movement.
As we outlined in part I, it’s possible to cost-effectively utilise these already-implemented technologies for fire safety purposes.

So how do we go about it?

1. Occupancy sensing.

We can deploy occupancy sensing to understand:

The total number of people per floor

Occupancy in pre-set zones, gridlines or predefined areas based on building escape paths or evacuation routes within the building design.

It’s vital that there are no ‘blind spots’ and the sensors provide an accurate count of all individuals at all times. This can be achieved by creating virtual threshold lines (that generate in/out counts) to understand the number of people within each of the spaces.

Although ideally incorporated during the base-build of a project, this technology is not static: new features can be implemented at any time or existing ones modified to suit any client/tenant needs.

2. Using the data.

The anonymous occupancy data gathered could be used in two different ways: informative or interactive.

The sensors could provide live data of occupancy to the building management in specific zones, floors or throughout the building. This could be used during emergencies to inform the management of the number of people in the building at the start of the evacuation and if anyone remains in the building after the evacuation. As a result, management procedures could be reduced and the need for manual occupancy counts, assembly points, roll calls, fire marshals etc could be alleviated.

This would be especially helpful in highly populated buildings with restricted management presence, such as co-working offices or university teaching buildings with no permanent staff.

It’s important to note that this data shouldn’t be relied on for life safety due to potential sensor inaccuracies, but rather used as supporting information.

Alternatively, the live data from the occupancy sensors could interact with the evacuation strategy and means of escape routes for the building.

By using the live occupancy data alongside with some intelligent signage etc, an evacuation could be optimised according to the density of people across the building, floors and zones by directing occupants to underutilised means of escape routes.

This could reduce the evacuation time of a building by ensuring the storey exits and stairs are used to their optimal capacity.

What’s going on behind the scenes?

The way the ‘interactive’ response is made possible is by analysing the live zonal occupancy data with machine learning algorithms. The zones can be configured in collaboration with the fire strategy to ensure the zones monitored accurately encompass the fire escape use cases. Traditionally, zones are placed to understand desk usage. To further this, greater, overarching zones can be configured to accurately count occupancy across banks of desks and group them as part of the optimised escape routes. This can then enable the smart building to trigger strategically placed digital signage to guide users to the most suitable point of exit (based on real-time occupancy data immediately prior to the alarm sounding), guiding each of the zones to the optimal exit to eliminate blockages and mass rushing in specific stair cores

As well as occupancy data, this live analysis of the optimal escape strategy would be based on:

– Understanding the precise location of fire/smoke (the heat detectors and overall fire detection system would be integrated into smart building platforms)

– Increased understanding (through associated metadata that can provide precise spatial coordinates, and all related systems and services)

– The fire evacuation strategy for the building

– The capacity of stairs and storey exits

Ultimately, this method uses real-time data to create an optimal evacuation, instead of fixed and pre-planned strategies that may not always be the best solution to ensure a safer building for all.