Russell, Yes, I used FDS-SMV, a full 3-D 'field model', open source software from the U.S. government (NIST). It is centered in the x,y directions of a .05m by 2m gap, and z dimension is .025m below the gap. So the ceiling jet crosses (2) panels, width-wise, with no sprinklers in them. Basically the presence of the gaps for the small piece I modelled delayed the activation by 5 seconds only.
thanks, Brad On May 30, 2016 3:31 AM, "Russell & Carol Gregory" <[email protected]> wrote: > Brad, > > Does that calculation differentiate where the sprinkler head is located? > In the gap???? Or just any where on the plane of ceiling. > > > > Regards, > > Russell Gregory > > Christchurch, > > New Zealand > > > > *From:* Sprinklerforum [mailto: > [email protected]] *On Behalf Of *Brad > Casterline > *Sent:* Monday, 30 May 2016 11:12 AM > *To:* [email protected] > *Subject:* RE: Cloud ceilings & sprinklers in gaps > > > > Excellent post Nicky; very good questions and observations. > I agree with what Mark S. said and suggest a few additional considerations: > 1) Use QR 155F cloud level sprinklers spaced slightly closer than the > plenum spinklers. > 2) Use QR 200F plenum sprinklers and avoid locating them directly above > the gaps. > > I modelled a piece of your scenario - - (4) panels with (3) gaps 'left to > right' at 3.5m height, and a continuous structural ceiling at 4m. > On the floor below the far left gap I put a 1,700 kW/m^2, t^2, FAST fire. > The panels are 1.1m wide and the gaps are .05m wide. Centered in the far > right gap is a QR, 155F, with a bulb height of 3.475m. Between 0 and 3m > height I used .05m^3 grid cells, and between 3 and 4m I used .025m^3. > Activation time was 99 sec. (14 hour calc time). > Then I eliminated the gaps and ran it that way. > Activation time was 94 sec. > > This would be an ideal scenario to model in detail using the Cloud Ceiling > Study you mentioned as the template. In fact you can copy/paste the sample > input file at the end of the report (from pdf to notepad), 'fix' a couple > things that get lost in that translation, and start tweeking to your > physical dimensions. Your clouds are not flat, but they are coplanar, and > the plenum depth is consistent. > > wbr, > > Brad Casterline > > On May 29, 2016 3:48 PM, "Nicky Marshall" <[email protected]> > wrote: > > 10 bays formed with Laminated timber beams, each with 24 panels. > > > > *Nicky Marshall* > > *Southern Regional Manager* > > *PROTECH DESIGN LIMITED* > > *Specialist Fire Protection Consultants* > > *Phone: *+64 (0)3 579 5577 *Mobile: *+64 (0)21 433 488 *Email:* > [email protected] *Skype: *nicky-marshall *Web:* > www.protechdesign.co.nz > > *Address:*105A Alabama Rd, Redwoodtown, Blenheim 7201, NZ *Postal: *PO > Box 4022, Redwood Village, Blenheim 7242, NZ > > > > *From:* Matthew J Willis [mailto:[email protected]] > *Sent:* Saturday, 28 May 2016 1:33 AM > *To:* [email protected] > *Subject:* RE: Cloud ceilings & sprinklers in gaps > > > > How many clouds? > > I ask because technically sprinklers are not required under them. You > stated 3’-6”.. > > > > R/ > > Matt > > > > *From:* Sprinklerforum [ > mailto:[email protected] > <[email protected]>] *On Behalf Of *Nicky > Marshall > *Sent:* Thursday, May 26, 2016 10:30 PM > *To:* [email protected] > *Subject:* Cloud ceilings & sprinklers in gaps > > > > I would appreciate if anyone has some thoughts on this arrangement: > > > > ~4m (13ft) high roof, ~3.5m (11.5 ft) high ceiling. Both slope 3 degrees. > > The ‘ceiling’ is to be made up of many Autex acoustic panels 1.1 x 2.3m > (3.6 x 7.5 ft), non-combustible, suspended with 50mm (2 in) gaps around > them. > > There will be sprinklers in the roof space because there are cable trays > with loads of combustible cables. > > They architect wants to put the sprinklers in the 50mm gaps to avoid > cutting holes in the acoustic panels. > > > > Whilst we are designing to NZS 4541, this code is silent on cloud ceilings > or anything like this, so I am looking for guidance from other sources. > > I note NFPA 13:2016 clause 8.15.24 gives some guidance and it seems to > indicate our ceiling arrangement would not require sprinklers above the > clouds or have any specific sprinkler location requirements. > > I am also aware of the Fire Protection Research Foundation report on cloud > ceilings. This seemed to suggest that each cloud must have its own > sprinkler – but doesn’t test with such small gaps – and recommends further > study in this area where coverage can be achieved without sprinklers in > every cloud. > > > > Three questions: > > Are the gaps small enough to just call this a ceiling – not a cloud > ceiling (what size gap affects the plume flow enough to make a difference)? > > Is it acceptable to locate the sprinklers within the small gaps, or will > this location significantly affect their operation? > > Do we have to cumulatively flow sprinklers above and below the ceiling, or > since NFPA permits this arrangement to not have roof space sprinklers > (suggesting heat flow into this space is not significant?), this would not > be required? > > > > Kind regards > > > > *Nicky Marshall* > > *Southern Regional Manager* > > *PROTECH DESIGN LIMITED* > > *Specialist Fire Protection Consultants* > > *Phone: *+64 (0)3 579 5577 *Mobile: *+64 (0)21 433 488 *Email:* > [email protected] *Skype: *nicky-marshall *Web:* > www.protechdesign.co.nz > > *Address:*105A Alabama Rd, Redwoodtown, Blenheim 7201, NZ *Postal: *PO > Box 4022, Redwood Village, Blenheim 7242, New Zealand > > > > > _______________________________________________ > Sprinklerforum mailing list > [email protected] > > http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org > > _______________________________________________ > Sprinklerforum mailing list > [email protected] > > http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org > >
_______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org
