how many sounders should be in a 3 storey house?

[bluesky]

Hi all, i am going to install a ACEL fire alarm system in a 3 storey house, 3 bedrooms on 1st fllor and 1 in the converted loft. smoke detectors in all rooms and one heat detector in kitchen,

however the client did not tell me how many sounders should be in the house, i checked the codes and going to design it as grade A and Category LD2. thinking to install 2 sounders in the house, one in ground floor corridor and the other one in 32nd floor corridor, looks fine based on my understanding but this is first ACEL system i am going to install, so will 2 sounders be enough?

cheers

 

[nikmet]

what about detectors for hallways and landings?

 

[bluesky]

yes, there are detectors in the hallways

 

[pushrod]

I thought that it is not so much the number of sounders but the minimum level of decibels recorded at certain locations ie bed heads when doors are shut. Sounders are usually located in the circulation areas, often top and bottom of large houses, but i am certainly no expert on this - would think you need to be looking at relevant BS and the manufacturer's instructions.

 

[robsparky1975]

Is it a HMO,if there are rated fire doors on every room,then its all down to the expected DB level at the bedhead,might be some fire alarm installers on here who can clarify,have you possibly looked into BS5839.

 

[Andy Ellis]

5839 states that the fire alarm SPL has to reach 75dB at the bedhead (for sleeping risk premises), all other areas 65dB. Think I'd go for one on each level

 

[bluesky]

on the 'electricians guide to fire and detection and alarm systems' page 46, the picture shows 2 sounders are ok for a 4 storey dwelling, but how can i know one bedroom has got 75DB at the bedhead?

 

[nikmet]

invest in a sound meter?, theyre not expensive

 

[Andy Ellis]

The only true way would be to measure with decible meter. its very difficult to advise, as sound behaves so differently in different environments. for example soft furnishings can have an effect, likewise hard floorings ect. Also how much the sound is obstructed, ie bedroom doors obviously lessen the sound level. The electronic sounders do tend to be fairly loud though and for domestic purposes im sure this would suffice.

 

[pushrod]

Also a fire certificate needs to be issued in certain cases after proper testing depending on the system and if it is an HMO there could be a whole host of other rules as they need to be licenced from the local council? TBH it is only odd bits of info i remember from when i did the 2330 - i just know that i don't know enough to do it without doing a lot of research and the relevant BS regs

 

[Andy Ellis]

Fire certificates have been obsolete for years. its all down to individual risk assesments, where by who evers name is on it, the book stops with! but domestic properties are not covered by this, unless you are planning to convert to student accom or a nursing home ect.. Also just thought, with regard to sounders, you need to consider ambient noise levels in the rooms, ie tv's and stereos ect.. obviously the SPL needs to be above this

 

[pushrod]

Fire certificates have been obsolete for years.

Just had a look in the IEE's 17th edition Electrician's guide to the building regs and page 126 shows a fire system certificate for D, E and F systems. Did nobody tell them?

 

[Andy Ellis]

lol clearly not! I've worked in fire industry for years and been on many training courses run by FIA ect, honestly, there gone. replaced by the regulatory reform order, which was brought into force in 2007 i think. under RRO risk assesments must be carried out in all work places

 

[bluesky]

Hi Andy, the only thing worry me is there is one room which has a ensuite shower room by the room entrance, so between the bed and staircase sounder there is a shower room, do you think the room can have enough DB?

Cheers

 

[Andy Ellis]

hmmm so long as there is only one door between the sounder and bed, assuming the shower room is only on one side, then it could well be loud enough. in my experience though, its hard to achieve 75db without sounders in the particular room, but not impossible. is the door to the bedroom fire rated? does it has intumescent strips fitted? both of these will reduce to sould level