Is there any specific easier method in determining Available Safe Egress Time after the simulation?

[veer prathihas]

I have been working on evacuation of a multi-storied building. A fire setup is done in the second floor at one of the corner. Is there any direct tools in FDS to use, so as I can directly get or calculate Available Safe Egress Time and Required safe egress time as well.

I have found one of the paper, in which an equation i determined with the concept of LLH but it is only for t squared fires and a maximum volume of 4800 cubic meters.

In my work, the volume of each floor is 30,600 cubic meters and a constant HRR has been given,

So, please help me, how can I attain Available Safe egress time by post processing of Simulations.

If you know any paper explaining how to calculate ASET, please share them here. 

[dr_jfloyd]

ASET is going to depend upon what your performance criteria are. There are no built-in FDS ASET criteria, it is a decision you need to make either based upon any applicable codes and standards or guidance from the fire protection literature.

Once you have established your performance criteria, you can then identify what FDS outputs are available that measure those criteria.

You could then either attempt to define some form of control system to identify when those criteria are first violated or you can just do it visually using Smokeview.

[Chris]

First determine how many people are in your building. Second use a evacuation-tool to calculate the egress time. Third the safe egress time is not the only quality criterion of an evacuation simulation: Also very important are person densities and jam times!

[veer prathihas]

There are 800 occupants in building, and egress time is 9 minute 50 sec. But, as I'm using FDS now, I want to calculate Available Safe egress time with respect to smoke being effected the motion of occupant.

Required safe egress time i.e., the total time in which complete floor being effected by the smoke such that because occupants visibility is reduced and considerable increase in toxic gases which effect evacuation has been calculated as 11 minutes. But i'm strucked with how to calculate Available safe egress time for the occupant to evacuate with out being effected by fire/smoke.

[dr_jfloyd]

If you are doing this work for an actual building where the lives of real people are at stake, please consider if you have the requisite skills to do this work.

I would suggest you review the chapters on egress and the health effects of smoke and heat in the SFPE handbook.  FDS is not going to predict ASET as single output.  You will need to define appropriate outputs for whatever tenability criteria you establish and then evaluate those outputs to determine ASET. 

If at 11 minutes you have visibility and/or toxicity conditions that would impact the ability of occupants to egress, I would argue that your egress is no longer safe.

[veer prathihas]

Thank you,
The fire properties what I have said has been just in fds simulations So i think there is no issue of real people life stake.
I knew there is no direct output for ASET from fds simulations. I want any papers or methods are suggestions like as you said sfpe handbook relating how to calculate safe egress times. So I can use standard calculations rather than assumptions.