Stairwell zones

[Graeme]

Gents

I am currently zoning a large FD+A system which has a section of offices ground to 3rd floor to which the stairwells are enclosed except for the ground floor which opens up into the main corridor. There are a couple of other areas with two floors again that open onto main corridor at ground floor.

As they are not fully enclosed do they still need to be on a zone of their own?

Thank you

G

[Allen Higginson]

Gents

I am currently zoning a large FD+A system which has a section of offices ground to 3rd floor to which the stairwells are enclosed except for the ground floor which opens up into the main corridor. There are a couple of other areas with two floors again that open onto main corridor at ground floor.

As they are not fully enclosed do they still need to be on a zone of their own?

Thank you

G

I take it that there is a set of doors from the stairwell leading onto the staircase to ground?that asided,if the remaining staricase is enclosed the the detection within should be on it's own zone.MCP's on zone of origin of course!
Any snow??

[Graeme]

no door seperating bottom of stairwell from main corridor.

snow at dinner time.

[Allen Higginson]

no door seperating bottom of stairwell from main corridor.

snow at dinner time.

So,what you have is like a [ or an L on sides with the long part representing the ground and the uprights the staircase.From the uprights (staircase) you enter the upper floors?

[Graeme]

4 storey office block.

2 stairwells.    1-enclosed

 2- 1st,2nd and 3rd floors have doors seperating the stairwell from the accomodation side and mcp's in the accomodation side but at the very bottom of the stairs at ground floor there is no door to seperate the stairwell from the open corridor of the ground floor.

The corridor is then broken by a door at either side of the stairwell. so would this small section of corridor count as the enclosed stairwell?

2nd building

open stairwell at ground floor onto entrance corridor about 5m long which again is seperated to the next corridor by a door.

and other side stairwell opens onto ground floor corridor which then goes 3 ways but all are seperated by doors.

[David Rooney]

Personally I'd think about whether an alarm originating from the ground floor corridor is going to be more confusing to the person investigating if it is on the same zone as the staircase.

If the normal route to the staircase from the panel is through the corridor then I don't think it matters that much.

Sounds more sensible to me for the ground floor corridor to be a zone, and the staircase from the first floor up to be a separate zone.

[Allen Higginson]

Tried sketching it (in tribute to the late Tony Hart) to get me head round it!
If the set(s) of doors are compartmentizing the ground floor stair case lobby then I would say (and in my opinion only) that it's an enclosed staircase and so should be on it's own zone from ground to top in both cases.Putting the detectors on floor specific zones within the staircase could give a miseading indication due to the nature that the smoke will travel.

[Graeme]

Thanks Allen and Dave.

I was thinking along the lines of Allen as the two doors in the corridor at the bottom of the stairwell do seperate it from the rest of the building but it's the other one i'm not to sure about as it open onto an entrance corridor which has toilets and a lecture room going off from the corridor although they are all seperated by doors. The entrance corridor is about 5m long by 3m wide.

i appreciated it's very hard to visualise if you have not seen the drawings so thanks for the input so far

G

[Allen Higginson]

Thanks Allen and Dave.

I was thinking along the lines of Allen as the two doors in the corridor at the bottom of the stairwell do seperate it from the rest of the building but it's the other one i'm not to sure about as it open onto an entrance corridor which has toilets and a lecture room going off from the corridor although they are all seperated by doors. The entrance corridor is about 5m long by 3m wide.

i appreciated it's very hard to visualise if you have not seen the drawings so thanks for the input so far

G

Entrance and front stairwell zone?

[Graeme]

could be an option Al.

thanks again