Audibility of Fire Alarm System in Sheltered Housing Scheme

[Tadees]

We have a sheltered housing scheme wherein the residents claim that they cannot hear the communal fire alarm system within their flats.

The fire alarm company have stated as follows:

?The sound pressure level at __________ is currently measured at 65dB (A) which is the minimum sound level of a sounder device or 5dBA above any background noise likely to exceed 30 seconds.

Guidance states that for areas where people are sleeping, sounder devices should produce a minimum 75dB(A) at the bed-head with all doors shut.

Sound levels can be upgraded to 85Db.  Guidance states that In all category LD systems the sound pressure level of fire alarm signals, if measured at the doorway of each bedroom (with the door open), should be at least 85 dB(A), irrespective of where fire is detected in the dwelling.

To increase the sound levels of the fire alarm will include a full system redesign as they need to consider the loop loading, space on the loop and if the system can take the extra devices.?

The only solutions I can think of are as follows:

(a) Additional sounders in the flat?  Would this be achievable or would the fire alarm system need upgrading?
(b) Link a detector within the flat to the communal fire alarm system?  Again, would this be achievable or would the fire alarm system need upgrading?

[Dinnertime Dave]

Sorry, a few questions -

Is this to alert residents of a fire in their flat? If no then why do they need to hear it inside their flat?
Is there a stay put evacuation strategy? If yes then why do they need to hear it inside their flat?

[Tadees]

That's what I am trying to find out at present

[Tom W]

DD raises the right questions.

I'd be interested to know how they are measuring 65dB(A). Calibrated sound measuring equipment is expensive, what equipment are they using and at what distance are they taking that measurement?

[Mike Buckley]

In answer to DD's 4th question, it could be that the residents need to know the fire alarm is operating in the common areas so that they will stay in their flats and not attempt to leave the flats until the alarm is over or they are evacuated from the flats if the whole building needs to be evacuated.

The other issue here would be how loud should the alarm be, considering the probable hearing problems of the residents?

With reference to Piglets point, I suspect that competent fire alarm companies would use some type of computer programme backed up by on site sampling. Other companies would probably go on fit sounders and hope!

[Dinnertime Dave]

DD raises the right questions.

I'd be interested to know how they are measuring 65dB(A). Calibrated sound measuring equipment is expensive, what equipment are they using and at what distance are they taking that measurement?

So the app on my phone is useless then

[colin todd]

Michael, would they not hear the alarm when they open the door so will then know to stay put.  They should preferably not hear anything at all, so they can sit watching Eastenders and sucking their boiled sweets in splendid ignorance of the fire.

[Dinnertime Dave]

In answer to DD's 4th question, it could be that the residents need to know the fire alarm is operating in the common areas so that they will stay in their flats and not attempt to leave the flats until the alarm is over or they are evacuated from the flats if the whole building needs to be evacuated.

In my experience it is better that they don't know.

[colin todd]

That is what I was trying to say Suppers.

[Dinnertime Dave]

Sorry Colin I think I posted just as you did. I always ignore the red warnings things. I'm glad we agree though.

[kurnal]

In answer to DD's 4th question, it could be that the residents need to know the fire alarm is operating in the common areas so that they will stay in their flats and not attempt to leave the flats until the alarm is over or they are evacuated from the flats if the whole building needs to be evacuated.

In my experience it is better that they don't know.

This may very well be true but here we have a scenario in which a system has been installed and some can hear it whilst others can't. Clearly an unsatisfactory situation. This will not lead to a satisfactory, co-ordinated or consistent response to fire alarms. On the other hand We don't know whether a communal system is justified or not and we don't know any other details of the cause and effect, or whether there is anyone on site to investigate and deal with such an alarm. The fire risk assessment is the tool to determine these issues and the appropriate response to the audibility issue.

[Tom Sutton]

I agree Kurnal, it all depends on the FRA and if a fire alarm is necessary then it should be heard by everybody in the premises, so they can determined their actions, which will depend on the situation.

[Tom W]

DD raises the right questions.

I'd be interested to know how they are measuring 65dB(A). Calibrated sound measuring equipment is expensive, what equipment are they using and at what distance are they taking that measurement?

So the app on my phone is useless then

The microphone in your phone isn't calibrated. It can give you an indication but if someone is being made to spend money installing more equipment you would expect the measurement to be correct.

[kurnal]

I agree Kurnal, it all depends on the FRA and if a fire alarm is necessary then it should be heard by everybody in the premises, so they can determined their actions, which will depend on the situation.

Or it could be a silent alarm that alerts the response team?

[Tom Sutton]

Would this apply in a sheltered housing situation are not the residents supposed to look after themselves?