Mixing of Part 1 and Part 6 fire alarm systems

[William 29]

I have been questioned recently by a fire alarm provider for a client we have in that they state they have never heard of mixing part 1 and part 6 systems in the same building.  We have on occasions in our FRAs recommended a “mixed” fire detection system to meet a specific objective i.e. flat conversions where it would be cost prohibitive or very difficult to upgrade the fire resistance to support a stay put policy.

I am aware the LACoRS guide makes reference to such systems but was wondering if there is any other documents that detail the mixing of part 1 and part 6 systems? 

[colin todd]

The concept of mixed systems comes from BS 5839-6.  I used the term in that standard cos an old dinasaur in the Home Office kept saying you couldnt MIX smoke alarms and systems because it said so in Home Office guidance. We were doing it in the early 1980s, but it technically went against the Home Office thinking.  It amused me to throw the term back at them because it is a sensible concept.

[kurnal]

If the Fire Risk Assessment determines that this is the appropriate solution then let no man put it asunder.  
What are the alternatives after all? There are two.

1- Appoint a fire alarm responsible person 24/7 to be on standby in case someone burns the toast in their flat.
2- Train all occupiers on how to silence and reset the panel. I have found that with such systems they do get a lot of experience at it.

With many addressable systems and multi sensor heads now available the Cause and Effects can be modelled to emulate domestic  smoke alarms whilst the heat element contributes to L3 protection of the communal areas, but this still creates the problem of someone having to reset the panel every time they burn the toast, because  BS5839-1 requires a manual reset.

Rafiki tried to overcome this with their SITA 200 panel which had a self reset function after 5 minutes if the smoke has cleared. The trouble was that its non compliant with BS5839 -1 and the medicine is as bad as the ailment because whilst the  system will reset itself after 5 minutes if the smoke has cleared it cannot do so more quickly. 5 minutes seems an eternity in such circumstances.

[William 29]

Thanks guys for the responses, much appreciated.  I put together a response using some extracts from Article 13 of the RRFSO, LACoRS and BS5839 parts 1 and 2 that should be enough to put the fire alarm company in its place.

[John Dragon]

We fit quite a few mixed systems, usually in flats and usually to a spec provided by the enforcing authority.
False alarms on the part 1 system are virtually eliminated but we do often come across disabled part 6 systems (often disabled with a hammer!). When fitted by Mr Sparks, the part 6 systems usually have ion smokes installed so false alarms from cooking are the norm.

[kurnal]

I have come across an unmanaged HMO comprising bedsits with cookers and someone has recently installed a full L2 part 1 alarm system - as it happens with with multi sensor heads (Gent sQuad). Evacuations are now taking place on a daily basis.

I am aware of the possibility to re-configure the detectors to state 8- smoke and heat. The concern is whether this will  give adequate protection to occupants of the rooms when asleep?

Unfortunately the CTec hush button is not compatible with Gent protocols.