Model Name: EgressPro
Version: 02
Classification: Consolidated egress model
Very Short Description: An egress model to predict
egress times and relevant
parameters for a deterministic time-line analysis
for a user
selected room, corridor, and stair arrangement.
Modeler(s), Organization(s): SimCo
Consulting
User’s Guide: Integrated in
Help File
Technical References: Help File
Validation References: The program uses established
engineering relationships as
given in references listed at the end of the program’s
Help
file.
The egress calculations are based on the theory
presented in
the SFPE Handbook on Fire Protection Engineering
as well
the Draft BS Code of Practice. The process of
egress
movement follows the general concepts of traffic
flow.
The model’s Help file provides a case study
to verify the
programs results.
Availability: SimCo@alphalink.com.au
Price: $ 150
Necessary Hardware: Intel architecture running
Windows 95 or higher
Computer Language: Delphi (pascal)
Contact Information: Peter Simenko,
SimCo@alphalink.com.au
Detailed Description:
EgressPro provides a fire-engineering
tool for assessing egress conditions during fire
emergencies in buildings. The program calculates
the response of sprinklers/heat or
smoke detectors and evaluates the response behavior
of people from the time of alarm to
the end of the egress from rooms, floors or buildings
on fire. The program predicts the
flow of groups of persons in emergency based on
the relationship between speed of
movement and the population density. Program provides
timing information required for
the construction of time-line presentations, usually
needed in fire engineering reports to
demonstrate whether the evacuation of the endangered
areas could be expected before the
fire tenability limits are exceeded.
Fire Detection Time
The program calculates the time
to alarm by calculating the detection time of
heat
detectors/sprinklers or smoke detectors in continuous
growth t-squared fires, based on the
Heskestad differential equations.
The procedure assumes the detector
is located such that it is exposed to both the
maximum ceiling jet velocity and temperature.
Correlation for ceiling jet temperature and
velocity were determined from limited experimental
data: (no beam or truss ceilings, no
cathedral ceilings, only smooth, horizontal unconfined
ceilings).
Pre-movement Time
The program enables the selection
of the pre-movement time, which depends on the
use
of the building and the type of alarm. Typical
values that may be used for design
purposes are provided for selected alarm types
and occupancies [Ref. BS-Draft].
Room Geometry and Occupant Density
Room geometry must be entered with
the egress door size. Value of the occupant density
can be selected from the table provided as part
of the program. The program multiplies
the selected density value with the room area
and displays it as the total number of
occupants in the edit box. Alternatively, the
user may enter his/her own number of
occupants in the edit box.
Stair Geometry and Type
The travel distance along the line
of travel on the stair slope must be entered and
the
stair-tread/riser geometry selected.
Egress Time Calculations
The program’s calculations
can be summarized as follows:
The number of occupants included in egress is
either entered or calculated by multiplying
the ‘occupant density’ with the corresponding
floor area.
The specific flow is derived by
multiplying the movement speed and the effective
occupant density. The exit’s effective width
is determined by subtracting the boundary
layer from its clear width.
The ‘Stair/Corridor Egress
Time’ is calculated next. It is the time
interval from the time
when the first occupant enters the stair to the
time when the last occupant exits the final
exit door.
The continuity of the occupant’s
flow is stipulated throughout and the specific
flow
densities and movement speeds are adjusted where
their limiting values exceed the
tabulated critical values.
