The LWF Blog

Fire Safety for Healthcare Premises – Fire Alarm System Design – Part 123

April 14, 2020 1:41 pm

In LWF’s blog series for healthcare professionals, our aim is to give information on best practice of fire safety in hospitals and other healthcare premises. In part 122, LWF looked at the assessment of fire alarm systems in healthcare venues and considered the non-patient areas where it may be that detectors can be omitted safely. In part 123, we discuss zoning for fire detection and fire alarms.

Within a healthcare building, all areas should be divided into zones for fire detection purposes (detection zones) and also for alarm purposes (alarm zones). Ideally, the alarm system for the building should be designed appropriately, so that alignment between detection zones and alarm zones is achieved. Where this cannot happen, it is acceptable that in non-patient areas, an alarm zone can comprise more than one detection zone, but a detection zone cannot comprise more than one alarm zone.

Within many (non-healthcare) buildings, this type of zoning is not required as a full alarm signal may be given in all areas and a full evacuation of the premises undertaken. However, this is not appropriate in a healthcare environment, where patient care is of the utmost importance.

The use of progressive horizontal evacuation (the movement of patients and staff from one area or fire-resistant compartment to a nearby area of safety for a set period of time or until the fire is controlled) in patient access areas requires that each sub-compartment should normally be in a separate zone.

It is common for healthcare streets to be extensively sub-divided by sub-compartment boundaries and so it is often the case that an alarm zone for a healthcare street may include several sub-compartments, but need to correspond where possible with the boundaries of adjoining alarm zones.

BS 5839-1:2017 – Fire detection and fire alarm systems for buildings. Code of practice for design, installation, commissioning and maintenance of systems in non-domestic premises sets out search distance criteria which apply where a fire alarm system is not addressable and the source of an alarm cannot be determined, however this does not apply in instances where the alarm is addressable and the source can be determined easily from the device location.

Any atrium area, commercial enterprise within the healthcare environment or hazard department should be in its own separate detection and alarm zone.

In Part 124, LWF will look at how alarm systems are designed to work specifically in a healthcare environment and how this can vary depending upon the type of care given in an environment. In the meantime, if you have any questions about this blog, or wish to discuss your own project with one of our fire engineers, please contact us.

Lawrence Webster Forrest has been working with their clients for over 25 years to produce innovative and exciting building projects. If you would like further information on how LWF and fire strategies could assist you, please contact LWF on freephone 0800 410 1130.

While care has been taken to ensure that information contained in LWF’s publications is true and correct at the time of publication, changes in circumstances after the time of publication may impact on the accuracy of this information.

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