After a year's work, BSI has issued BS 9251:2014(fire sprinkler systems for domestic and residential occupancies – code of practice) for public comment. The Revised standard is considerably changed from the 2005 version, providing more clarification and insight. One of the significant changes is that it has removed 'residential' and 'domestic' classifications in favour of type 1, type 2 and type 3 classifications. This is undoubtedly a move in the right direction and will be given much more flexibility.
Some of the manager changes are:
- 2.04 mm/min design density for type 1 occupancies (domestic)
- 2.80 mm/min design density for type 2 and 3 occupancies
- Sprinkler head can cover 25 m² area
- Maximum spacing between sprinklers is 5.5 m
- Blocks of flats greater than 18m in height will require a minimum of 30 minutes of water supply.
The new standard also provides a considerable amount of guidance on such things as the effective capacity of the storage tank. The calculation of the most unfavourable and favourable area is more clearly defined and asks for what is basically a Qmax calculation to find the maximum flow demand of the system to determine the tank capacity.
The standard also tries to indicate its limitations and that it is not an appropriate standard in some circumstances. These are referred to as 'abnormal circumstances or where the system is being used for compensatory features or removing other fire safety provisions.
There's plenty for everybody in the standard, but undoubtedly, some of it will be controversial, and many comments are expected to be received. If you want to look at the standard or submit a comment, you can do so through the BSI draft review website and type in 'BS 9251' in the 'search by keyword'. You will need to register on the site before you are able to read or comment on the standard. You have until May 31 to submit your comment, and it is envisaged that the revised standard will be published before the end of this year.