Designing fire detection systems for mixed-use buildings Paul Pope, Head of System Integration and Technical Support at Apollo Fire Detectors

A mixed-use building naturally combines commercial, residential, hospitality, and retail within a single property, which can make designing a fire detection system quite complex and challenging.

The way that each part of the building is used, the movement of people, occupancy levels and the need for phased or partial evacuation must be considered when choosing the most appropriate fire detectors for the different environments. As such, it is vital that architects, fire system designers, installers and manufacturers work closely together.

Safe evacuation
The safe and timely exit of the building’s occupants is of utmost importance in the event of a fire. A fire detection system can be designed so that a building can be evacuated individually or in sections, which ensures minimum disruption and avoids unnecessarily evacuating building users who are not at risk due to their position in the building in relation to the fire. A ‘phased’ emergency and personal evacuation plan should also consider the needs of disabled and sensory impaired people as well as those who may be unfamiliar with their surroundings, and those who speak different languages.

The right fire protection for each building area
It is important to assess every area of a mixed-use building to ensure the appropriate type of detection is used for the differing fire risks. For example, a hotel with busy kitchens and high 24/7 occupancy levels will have different fire risks and flammable materials than an office space.

The types of fire that can occur can vary from slow smouldering fires to rapidly flaming fires with little smoke. Manufacturers have developed different types of detectors for different types of fires and environments:

  • Optical smoke detectors are good for a wide range of smoke types symptomatic of early stages of fire. They are suited to detecting slow burning, smouldering fires which produce large smoke particles and are often used in areas such as bedrooms, escape corridors, and electrical switch rooms.
  • Heat detectors offer protection in environments that are dirty or smoky in normal conditions, such as kitchens or garages.
  • Multi-sensor detectors offer a combination of smoke and heat sensors. For their sheer flexibility, multi-sensors are the best general-purpose detectors currently available. They combine optical readings with temperature change to give a rapid response to the widest range of fires of any detector type, dramatically improving rejection of unwanted alarms.
  • Carbon monoxide (CO)/heat multi-sensor detectors provide good early warning of deep-seated, smouldering fires and are unaffected by common sources of unwanted alarms such as steam, cooking or dust.

Taking advantage of the latest technology
Analogue addressable fire detection technology is an ideal choice for mixed-use buildings where accurate identification of a fire is important because each individual detector can be pinpointed. When combined with a graphical display of the building, this information will indicate to building management staff and attending fire and rescue personnel exactly where and how the fire is spreading and, consequently, where their resources should be focused.

Modern and technologically advanced fire detection solutions are ideally suited to purpose built mixed-use modern buildings as they significantly improve the detection of smoke, enhance the reliability of the detection process and reduce the risk of false alarms. They are also stylish which suits the demanding aesthetic requirements of mixed-use buildings. They are also usually tamper-resistant, making them ideal for use in public areas of mixed-use buildings or areas where low ceilings mean that detectors may be more prone to vandalism.

Other considerations when choosing a fire detection system are ease of maintenance and servicing, and advanced features such as self-test capabilities and drift compensation warnings on dirty detectors.

Finally, the latest fire detectors are equipped with different operating modes, so that the sensitivity level of each device can be tuned to match the likely environmental conditions, which can be particularly beneficial in mixed-use buildings and can dramatically reduce false alarm incidents.

A joined-up approach to fire safety
As we’ve seen, designing a fire detection system for mixed-use buildings requires careful consideration of a number of factors. As with any building type, there is no ‘one size fits all’ solution and that’s why a joined-up approach between architects, manufacturers, fire safety officers, consultants, installers and end customers is required to identify the best bespoke solution for every project.

For more information on Apollo products visit www.apollo-fire.co.uk.