FireNet Community
FIRE SERVICE AND GENERAL FIRE SAFETY TOPICS => Technical Advice => Topic started by: David Rooney on June 09, 2009, 07:18:19 PM
-
A large plush hotel in London known to one or two of the members for sure.....
Part of the strategy is that a single detector in a room going into fire will start a 90 second "acknowledgement" timer (followed by a five minute search timer).
Simultaneously sounders operate in the room of origin only as soon as the detector activates.
Basically if either timer runs out or second detector/call point activates then a full evac alarm is provided by a voice alarm system throughout (including the bedrooms.)
It appears that the sounders in the rooms are basic 24volt switched by relays but they are not monitored for any fault conditions.
Forgetting the two stage timer and possible excessive search period.......Is the fact the bedroom sounders are not monitored a variation or not ??
-
if the sounder in the room didnt activate for 6 mins 30 secs would the risk assessment jusify that?
-
The assessment is likely to say the hotel is manned 24/7 and therefore a fire condition is likely to be confirmed long before this period is up...
-
if initial sounders are not required in the rooms then why would they be installed in the first place. if the alarm circuit is unmonitored the system could not comply with 5839 and would be imposible to certificate.
Surely?
-
The VA system should cater for this totally , thats if its a Va and not PA , sounds like a modified half breed of a part1 and part 6 combined.
-
The principle of the cause and effect sounds reasonable, but how it has been achieved sounds like a lash up.
As you know Dave using modern systems, delay blocks and sectors configuring this type of cause and effect is fairly straightforward. ( for you not for me- I still only drive the things)
As it is set up I would say that its a variation and would be wondering what other issues may lurk within.
-
I wonder whether I know of this Hotel?
The LFB (well a particular IO) had an issue with a very large Hotel with regards to time delay procedures. The issue revolved around the fact that whilst Hotel staff would be made aware of the AFD's actuation, the relevant person (customer) within the room/suite would not being alerted to a fire signal immediately during the search period. If I recall correctly. this was more of an issue in suites where there was a possibility of persons being/sleeping in rooms other than the room of origin.
The IO determined that this system was unsuitable and requested a local sounder in each room which would actuate (in the room/suite of origin) immediately, thereby protecting the relevant person(s). The last I heard was the Hotel were unsure whether this would be possible using their currently installed system and were investigating the most cost effective way of installing the sounders.
This might (or might not) account for why such as system has been installed and installed in a non standard way.
-
the system is up for refurbishment hence I don't want to broadcast the name... but suffice to say the system is around 15 years old now the suites do generally have a sounder (unmonitored) in each room... this may well have been an afterthought installed after the original FD&A system was installed.
The voice alarm is a monitored system but obviously not to modern day spec.
I just don't understand why these sounders aren't monitored, and if there is actually any reason why they should be if the VA system is the "primary" alarm...?
-
David, surely it is obviously a Variation to BS5839 Part 1 2002 + A2 2008.
That something might have been agreed as suitable currently or previously, doesn't make it exempt from being highlighted as a Variation to the current Code of Practice.
-
I think it depends on what angle you are coming from Wiz....
If the PA system is accepted as the means of warning with its delays etc etc meaning the person in the room of origin may not get warned for upto 6.5 minutes then the local alarm doesn't really come into it and could be a bicycle bell.... therefore if its not needed, its not a variation.
But if the local alarm is required to wake the person in the room instantly then surely it should be monitored and as it's not, should be a variation?
I suppose the other question then is in any hotel where a delay strategy is employed, is it acceptable to delay the sounders in the room of origin??
-
We maintain and have for many many years, some very well known barnds of large national hotels, and their policy is to delay the sounders for upto 5 minutes on activation on 1 detector (2nd detector or MCP triggers, then full alarm). No alarm is given in the room of origin until the delay timer has expired.
These hotel chains are in excess of 200+ hotels national each.
I think it appears to be common in hotels this kind of delay.
Although, all the hotels are worried about in these instances is lost revenue from unwanted evacuation.
-
If they are additional/secondary then surely they don't come under the original specification if they weren't included in it (as Dave says,could be bicycle bells or party blowers on compressors!?)
-
I think it depends on what angle you are coming from Wiz....
If the PA system is accepted as the means of warning with its delays etc etc meaning the person in the room of origin may not get warned for upto 6.5 minutes then the local alarm doesn't really come into it and could be a bicycle bell.... therefore if its not needed, its not a variation.
......
David,
The angle I am coming from is that you are reporting on the system in respect of current BS recommendations. If the angle is different then, obviously, my comments might be different!
Firstly, If the sounder is not needed why was it ever installed? I can't believe a hotel chain spent good money installing sounders that they didn't need!
But is it your problem anyway?
You appear to be spending your time trying to justify being able to ignore these sounders so they don't have to be noted as a variation. Why are you doing this?
It is obvious that you haven't been shown any documentation proving that this variation has previously been highlighted and has been approved by the relevant persons. If this existed you probably wouldn't be asking the question.
The point I was trying to make is that the sounders obviously form part of the fire alarm warning system and as such if they don't comply they should be highlighted as a variation.
As an analogy, if, for example, I found an area covered by two smoke detectors and one of these detectors was, say, incorrectly wired so that it wasn't monitored as per the recommendations but by calculation I worked out that one 'good' detector was actually sufficient to cover the whole area, I would still have to highlight the Variation of the non-monitored detector in my report, wouldn't I?
Your problem is the same. The sounders are not monitored to BS. The question for you surely isn't whether they are needed or not; They are installed as part of the fire warning system and they don't comply to current B.S.
In my opinion you should highlight them as a Variation and then let the relevant persons assess the risk and decide if not having them monitored is acceptable or not.
-
Just slightly off topic but what about secondary sounders in the industrial sector say,where they are mains operated and not monitored?They are part of the fire alarm strategy for the building due to excessive noise but are not monitored.They standard makes reference to these saying that they should be linked to a contactor and only operate when the machinery/process is in operation but they are not monitored.
-
Buzz, your point is a good one and not really that far off topic, but I don't think it applies in this case.
From David's explanation, it seems to me that these sounders were almost certainly installed because of the delay before voice evac. and not because they are needed to re-inforce any other audible warning.
David's explanation states that they operate in the room of origin only. Therefore they are there to provide the room occupant with an early warning (i.e not having to wait for the voice evac. to operate). Because of this they are an integral part of the fire alarm warning system and are surely subject to all the standard BS recommendations.
-
Surely, given the fact that there must be some cause and effect strategy in place to operate these local sounders, it cannot be a huge task to offer the customer the option to make them monitored. I assume the must be currently running off an interface? Change this to sounder controllers of what ever protocol is running and hey presto, monitored sounders
-
Having re-read the OP it appears that they may be using the remote LED to switch the room sounder (unless I have missed something else in my re-read!).
What protocol is it Dave - if it is Apollo you could use the ancillary sounder base which works the same as the above,gives 85dB at 1 metre and is monitored in that if the head is removed you get a fault up,thus keeping everyone happy with very little extra outlay!?
-
All very good points wizz big and buzz......!
The system is going to be replaced. My pointy for asking the question is simply because I am curious to know whether everyone thinks this is right wrong or indifferent....
The system is presently a Wormald PBS2 (!!!!!)
Yes sounder controllers is already a considered option, but IF the room sounders are not required under BS then there is no point.
The sounders could well be controlled by an LED output/relaybase as I'm not sure the PBS system has the processing power to handle the cause and effects which probably amount to around 800 separate events in this place.
Regading the side issue of whether the sounders are delayed in the room or not, this is perhaps more a moral question than a technical one...!
-
There is no cause and effect if they are using the LED Dave (as is the case with the modern Apollo solution) as it operates when the head does.
It's an easy solution if the aim is to waken the room occupant if their detector activates whilst permitting an investigation time prior to needing to get everyone out.
-
Indeed. It seems as if the system was installed using the voice alarm/delay method, then after the event someone wasnt happy with the delay in the point of origin so the sounders were provided after.
I think the PBS runs on system sensor protocol, does it not?
-
Yep Mr Fella.... tis SS protocol.....
So is general concensus that a reasonable risk assessment might conclude that the local room sounders are not necessary?
In which case presumably the RP has the authority these days to do away with them despite what the local IO might think (if he's still around) considering the evidence that other hotels also employ delays without alerting the occupant in the room of origin....?
-
Therefore they are there to provide the room occupant with an early warning (i.e not having to wait for the voice evac. to operate). Because of this they are an integral part of the fire alarm warning system and are surely subject to all the standard BS recommendations.
Wiz this is the crux of the issue. The jury is out on this and I believe one of our regular posters is involved in a current determination to clarify this point.
In Messys example of the hotel suites, it was clear that the detection and alarm was provided precisely for the benefit of the occupant of the room.
But in most hotels the detection is there to protect the escape routes as per the L2 category of BS5839 part 1. Hence the BS still allows heat detectors in rooms. So it could be argued that that the alarm sounder in the room is over and above the basic requirement for compliance. But I still agree with you that it should be reported as a variation.
My personal view is that we should protect the occupants of hotel rooms by the provision of smoke detection and sounders- because it can be done easily and cheaply. But thats back to an old chestnut and hopefully the forthcoming determination will provide clarification.
-
Therefore they are there to provide the room occupant with an early warning (i.e not having to wait for the voice evac. to operate). Because of this they are an integral part of the fire alarm warning system and are surely subject to all the standard BS recommendations.
Wiz this is the crux of the issue. The jury is out on this and I believe one of our regular posters is involved in a current determination to clarify this point.
In Messys example of the hotel suites, it was clear that the detection and alarm was provided precisely for the benefit of the occupant of the room.
But in most hotels the detection is there to protect the escape routes as per the L2 category of BS5839 part 1. Hence the BS still allows heat detectors in rooms. So it could be argued that that the alarm sounder in the room is over and above the basic requirement for compliance. But I still agree with you that it should be reported as a variation.
My personal view is that we should protect the occupants of hotel rooms by the provision of smoke detection and sounders- because it can be done easily and cheaply. But thats back to an old chestnut and hopefully the forthcoming determination will provide clarification.
....and hopefully an amen to that!
-
Prof. Kurnal,
I'm now very worried.
I thought this post was only about the need or not for a Variation to highlight unmonitored sounders.
It quickly transpired that some people thought that if the sounders weren't strictly necessary then a Variation was not necessary.
I still think a Variation for the lack of monitoring is necessary, but all this pales into insignificance against part of your last post. You wrote:
But in most hotels the detection is there to protect the escape routes as per the L2 category of BS5839 part 1. Hence the BS still allows heat detectors in rooms. So it could be argued that that the alarm sounder in the room is over and above the basic requirement for compliance.
I had no idea that the category of a system determined the requirement for sounders or not!
I would put it to you, my learned friend, that it doesn't matter a jot if you have smoke or heats in a bedroom and it doesn't matter what the L system category may or may not be. Quites simply sufficient sounders must be installed to achieve the recommended minimum sound level in all instances. This might include a sounder in the bedroom even if the bedroom only has a heat detector or no detectors at all.
Have I misunderstood what you meant?
-
Dr Wiz
I had assumed that in this case the room sounders in question were ancillary to the voice alarm system used for general evacuation and only there to give an immediate warning to the occupant because the fire is in their own room, ie performing the role of a domestic smoke alarm. I had assumed that they were NOT installed because of concerns over audibility of the main voice alarm cos that would be really confusing and may prevent people from hearing the voice alarm......
(just about to launch my new collection of confusing postings by Kurnal volume 19999)
-
Men.... please make as many assumptions as necessary because I have no definative answers.
This is simply an existing system I have come across, and am bi curious as to how and why it works the way it does.
And along the way am opening up the exploratory canals as to whether this complies, doesn't comply, and the ethics of not waking the person in the room immediately on activation of the local detector.
I don't believe the sounders are installed in order to attain 75db... the VA system can manage that.
So I assume they are there to wake/protect the sleeping risk whch as K rightly says, is not the objective of an L2 system. In which case:
A. I agree they are a variation as they are not monitored, moreover, if they were required then I think it was a diabolical variation (or a cheap fix) not to monitor the circuits !
B. Is it reasonable to delay sounders in the room of origin? (at £sillymoney/night i think i'd like to be woken straight away if there was a chance my room was on fire!!)
-
........This is simply an existing system I have come across, and am bi curious as to how and why it works the way it does................
David, are you on the wrong site?
I myself am buysexual - if I want sex, I have to pay for it!
-
........This is simply an existing system I have come across, and am bi curious as to how and why it works the way it does................
David, are you on the wrong site?
I myself am buysexual - if I want sex, I have to pay for it!
Thats the end of the salsa dancing in The Empire for you my boy!!!!
-
Errrr I'm a biker.... salsa.????.......moi.....???!!! :-X
-
........This is simply an existing system I have come across, and am bi curious as to how and why it works the way it does................
David, are you on the wrong site?
I myself am buysexual - if I want sex, I have to pay for it!
I think we all have to pay for it in some way shape or form..... and now the pound equals the euro you can't even offer a cheap weekend away....!!
-
Errrr I'm a biker.... salsa.????.......moi.....???!!! :-X
Sorry,Glam Rock is more your thing on a Friday right enuff!
-
oh yes.... can't beat a bit of glitter.........!!
Anyway... what about the question !!!!!
-
I think the only outstanding question (not the original question)(or the question about sexuality) is whether a delay before voice evac is acceptable in a hotel?
Is this the question, David?
-
Yes I think we should leave sexuality issues firmly in the closet.... amongst the frilly shirts and shawaddywaddy outfit...... and ask youself....
"would i want to be woken straight away if there were a fire in my hotel room, or is it acceptable to leave me in slumber for 5 minutes to possibly wake up dead.......?"
:)
-
"If some people have skeletons in the closet and homosexuals come out of the closet,does that mean that homosexuals are scared of skeletons?" - Jimmy Carr.
-
"would i want to be woken straight away if there were a fire in my hotel room, or is it acceptable to leave me in slumber for 5 minutes to possibly wake up dead.......?"
:)
Is that not the same as asking whether you agree with the current BS5839 part 1 that continues to recommends that heat detectors in hotel bedrooms are ok.
The outcome of the two scenarios is identical.
-
Prof. K, surely the heat detector in hotel bedroom scenario has arisen historically because of the number of unwanted alarms due to guests smoking and the problem of steam from the bathroom. It was obviously seen as the lesser of two evils. One being the risk that a heat detector wouldn't operate quickly enough to ensure the safety of the person sleeping in the room. The second being the evacuation of a hotel for unwanted alarms is costly for the hotel and leads to lack of confidence in fire detection systems by the public. Do you think the former is a greater risk and real problem than the latter? In all events I'm sure a solution for the smoking/steam in bedroom scenario will soon be resolved by technological advances. In fact, haven't Apollo recently announced a new smoke detection technique that would do this?
Curious Dave, the reason for the delay in voice evac. is obviously for the same reasons given above. Presumably someone with the appropriate knowledge has approved the delay as a Variation. If we are talking about a modern well-built hotel, good fire doors, plenty of fire escape routes etc. etc. with the delay only relating to detectors in rooms of good fire resistance (but not of those on fire escape routes) then I think I would be happy staying at the hotel of your scenario. At least the detector in my own room would provide an immediate local warning, although I'd want the room sounder wiring to be monitored!
-
Prof. K, surely the heat detector in hotel bedroom scenario has arisen historically because of the number of unwanted alarms due to guests smoking and the problem of steam from the bathroom. It was obviously seen as the lesser of two evils. One being the risk that a heat detector wouldn't operate quickly enough to ensure the safety of the person sleeping in the room. The second being the evacuation of a hotel for unwanted alarms is costly for the hotel and leads to lack of confidence in fire detection systems by the public. Do you think the former is a greater risk and real problem than the latter? In all events I'm sure a solution for the smoking/steam in bedroom scenario will soon be resolved by technological advances. In fact, haven't Apollo recently announced a new smoke detection technique that would do this?
Curious Dave, the reason for the delay in voice evac. is obviously for the same reasons given above. Presumably someone with the appropriate knowledge has approved the delay as a Variation. If we are talking about a modern well-built hotel, good fire doors, plenty of fire escape routes etc. etc. with the delay only relating to detectors in rooms of good fire resistance (but not hose on fire escape routes) then I think I would be happy staying at the hotel. At least the detector in my own room would provide an immediate local warning, although I'd want the room sounder wiring to be monitored!
I thought that the heat or a smoke detector in rooms leading onto escape corridors was purely for the protection of the escape route for L3 and not for actual protection of that room (ie - once the heat gets as far as the doorframe and assuming of course that the door is 30 minute).
-
I thought that the heat or a smoke detector in rooms leading onto escape corridors was purely for the protection of the escape route for L3 and not for actual protection of that room (ie - once the heat gets as far as the doorframe and assuming of course that the door is 30 minute).
Buzz, a detector in a room leading on to an escape route could equally be part of L1 systems and that might be the case in the scenario we have been discussing.
Detectors in rooms leading on to escape routes in L3 systems do have a special dispensation regarding potential siting of that detector. Is it this you are thinking of?
-
In the L1 system the aim is the earliest possible means of raising the alarm to achieve the longest time to escape - this in my opinion then includes the person in the bedroom which would mean that a smoke detector would have to be used to achieve this.
You're right though,I was referring to the mounting of a detector on the doorframe of the room for the L3.
-
Buzz, please don't think that I am purposely 'picking' on all your posts for any silly reason, but I would argue that the obvious purpose of any fire detection system (no matter the category!) is, as you state, the aim of the earliest possible means of raising the alarm to achieve the longest time to escape
I would agree that this would be best achieved by a smoke detector in a bedroom, but it has become a fairly common practice to sometimes use heat detectors because of the high unwanted alarms risk from smoke detectors in hotel bedrooms. The BS recommendations infer that the appropriate type of detector always is that which provides the best sensitivity butwith regard to the unwanted alarm risk, so this means heat detectors can sometimes be used. as an alternative to smoke. The BS recommendations indicate that the only place that heat detectors can't be used in place of smoke detection in any circumstances is on escape routes.
Furthermore, and I'm really not being pedantic, but it is above not on the doorframe for the L3 dispensation. Sorry to pick up on one word but it could mean a lot of difference in a court of law, m'lud :)
-
Too thick skinned fer that Wiz (and it is a forum after all).
The use of the heat detector in the room does not give adequate life protection of occupant of said room if they are asleep (which,after staying in so many hotel rooms,are all they are good for!) and I personally hate to see a heat in the room for that reason.Nice smokie in the middle of the room works for me.
-
I understand the basis for your preference. The point I am making is that your preference is not necessarily a recommendation of BS. So the unknowing shouldn't be surprised to find a heat detector in their hotel bedroom and they can't say 'this doesn't comply with BS!'
-
The issue of HD and detection in Hotel rooms has been discussed at great length here and it seems there's still much unease about it.
However, the example I gave of local sounders in a large London Hotel, related to Hotel suites - flats within the building. The aim of the local sounders would be to operate if a detector head operated anywhere in the suite (including the MOE hallways) and not just in the room where the punter is sleeping.
It's this type of accommodation which I believe is unsuitable for delayed actuation as an actuation involving the suite's escape route would delay the alarm. Surely that goes against the design principles of both L3 and L2 (the coverage which may be found elsewhere in the Hotel).?
-
I understand the basis for your preference. The point I am making is that your preference is not necessarily a recommendation of BS. So the unknowing shouldn't be surprised to find a heat detector in their hotel bedroom and they can't say 'this doesn't comply with BS!'
Wiz - fair enough,I am mixing what I see as better practice with what is acceptible but I still maintain that if an L1 system is specified then heat detectors do not give an adequate early warning to meet what is the aim of that category.
Reminds of the anecdote regarding the smoke detector and sprinkler salesmen at a conference in a hotel..
Both were debating the merits and effectiveness of their own product so,to settle it,the guy with the smoke detector makes the sprinkler guy an offer.
"Tell you what,lets both of us go to out rooms and you mount your sprinkler head in the room and I'll put up my smoke detector.Then set a fire in the wastepaper bin beside the bed.Only when our own devices activate can either of us leave the room"!
That's far better than my own anecdote regarding a hotel room,a bottle of Bush and cheese sandwich btw!