The LWF Blog
Fire Engineering for Healthcare Premises – Examples of Fire-Engineered Healthcare – Part 72February 7, 2022 1:19 pm
LWF’s blog series for healthcare professionals aims to give information on best practice of fire safety in hospitals and other healthcare premises. In part 71 of Fire Engineering for Healthcare Premises, LWF looked the example given in HTM 05-03 of how fire engineered design was used in a hospital design where there were elements of non-compliance. In part 72, we discuss the case of an atrium as the centre of a district general hospital.
A design which proposed a two-storey atrium in a 533-bed Nucleus hospital contravened the HTM guidance at the time. The design team worked on three fire strategies to mitigate the effects of the various fire scenarios relating to the atrium design. These were the ‘Sterile Tube’ strategy, powered smoke ventilation option A and powered smoke ventilation option B.
The sterile tube strategy was based upon the atrium containing no significant amount of flammable materials. The sides of the atrium were to be fire-resistant and impermeable, which meant that the windows must be fire-resistant and could only be opened by the Fire Service. Rooms adjacent to the atrium would be fitted with sprinkler systems to minimise and control fire development and spread.
Powered smoke ventilation option A involved the fitting of a mechanical smoke extraction system to the atrium, designed to extract smoke produced by a fire within the atrium. The system would be sufficient to ensure that the accumulated smoke layer would remain above the lintels of the upper storey windows. This would ensure that there was no requirement for fire-resistant glazing to the windows and would mean atrium boundary windows could be openable by occupants.
The fuel load on the atrium floor would be restricted, allowing an acceptable fan size. The air inlet area would be situated on the ground floor with the air-inlet speed in escape doorways not exceeding 5ms-1. The fan capacity was proposed at not less than 8.5ms-1, allowing sufficient capacity to deal with a fire in an abutting room.
In Part 73 of LWF’s blog series, LWF will continue discussing the fire design for an atrium as the centre of a district general hospital by looking at powered ventilation option B. 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.