The long-awaited revision to BS 9251 (fire sprinklers systems for domestic and residential occupancies – Code of practice) has now been published by BSI and is available to purchase through their website, the standard will come into effect from 31 October 2014. The new BS 9251 standard is a comprehensive revision and will help both designers and specifies provide excellent fire sprinkler protection to help protect the most vulnerable in our society.
A major change is that the standard no longer has 'domestic' and 'residential' as categories but instead they have opted for three classifications Type 1, Type 2 and Type 3. A Type 1 is generally what we would have known as a 'domestic' system in the old BS 9251 standard, Type 2 is high-rise flats > 18m in height and Type 3 cover larger residential care facilities. This is only a glimpse of what is a quite complicated table and classification system but it does illustrate the comprehensive changes which have been made.
Another significant change is that the standard now specifies a design density and this varies according to the classification of risk and can be as low as 2.04 mm/min to 2.80 mm/min with a requirement in some circumstances 4 mm/min from a single sprinkler head. The design density approach will be a major departure for many working in this field of fire sprinkler protection and the use of hydraulic calculation software such as FHC will allow designers to optimise their sprinkler design ensuring a cost-effective solution.
We have only covered a very small part of the new standard and we strongly recommend that anyone involved in this area obtains a copy of BS 9251: 2014 urgently and becomes familiar with its new methodology and requirements.