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Room with Hallway

Pathfinder 2011

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Room with Hallway This example has 16 occupants in a room that leads to a hallway with an exit.

Figure 1: Problem geometry

Create Geometry To select Metric measurements:

1. On the View menu, click Units and select SI.

To specify snap grid spacing:

1. On the View menu, click Edit Snap Grid....

2. In the Snap grid spacing box, type 1.0 m .

3. Click OK.

To create the room with a hallway:

1. In the View toolbar, click Top View ( ).

2. In the Tools toolbar, click Add a Rectangular Room ( ).

3. To add the first room, click and drag from point (X1: 0.0, Y1: 0.0) to point (X2: 5.0, Y2: 5.0).

4. In the Tools toolbar, click Add a Rectangular Room ( ).

5. To add the hallway, click and drag from point (X1: 5.0, Y1: 2.0) to point (X2: 7.0, Y2: 3.0).

6. To merge the room and hallway, hold the CTRL key and use the Selection tool ( ) to select the

two rooms. Next, right-click anywhere on the selected rooms and from the pop-up menu click

Merge. The room and the hallway are now one room.

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Figure 2: The room and hallway

Add Exit Door To add the exit door:

1. Click the Add a new Door tool ( ).

2. Click and drag from point (X1: 7.0, Y1: 2.0) to point (X2: 7.0, Y2: 3.0).

3. In the Name box, type Exit.

Figure 3: After drawing the exit door

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Add Occupants To add 16 randomly distributed occupants to the room:

1. On the left toolbar, click the Add Rectangular Group of Occupants ( ).

2. In the Count box, type 16.

3. Click and drag from point (0,0) to (5,5) to define the space in which the occupants will be

added, Figure 4.

Figure 4: The occupants in the room

The occupants will be assigned the default Behavior, which is to leave the building using any available

exit.

Run Simulation To run the simulation:

1. Save your document to a new folder. Use the name room_with_hallway.pth.

1. On the toolbar, click Run Simulation ( ). By default, the problem will be solved using the

Steering behavior mode.

2. A summary report is provided in the analysis dialog. It provides FIRST IN and LAST OUT times for

each room and door.

View Results When the simulation is finished, the 3D Pathfinder results window will display.

To view results:

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1. Click the Play button. This will display the occupants as cylinders with their direction indicated

by a triangle.

2. At any time click the Pause or Stop button. You can drag the time line to control the animation.

3. To view occupants as people, click the Stop button, on the Agents menu, click Show as People,

then click the Play button, Figure 5.

Detailed information for each room is provided in comma-separated value (CSV) files that can be

imported to a spreadsheet. The LAST OUT exit time is 12.5 seconds in steering mode.

Figure 5: The 3D results view using steering behavior

Select SFPE Mode Pathfinder provides the option to select different simulation modes. The SFPE movement mode is

consistent with the assumptions used in the SFPE Engineering Guide - Human Behavior in Fire (SFPE,

2003). Assumptions include:

1. The occupants move toward the exits using the shortest path

2. The maximum occupant speed is a function of room density

3. Occupants move independently and can occupy the same space as other occupants

4. Queues form at doors, with the flow rate through the door as specified by SFPE guidelines.

Because multiple occupants can occupy the same space, a queue may appear as a single

occupant.

To select the SFPE mode:

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1. On the Simulation menu, click Simulation Parameters....

2. Click the Behavior tab.

3. In the Behavior Mode box, select SFPE.

4. In the Door Boundary Layer box, type 0 cm. This removes the boundary layer from the flow

calculation of the door

5. Click OK.

On the File menu, click Save As… and save the model using the name

room_with_hallway_sfpe.pth and run the analysis. The LAST OUT time in SFPE mode is 13.1

seconds.

Compare SFPE Calculation with Expected Result The SFPE egress time is calculated as the time it takes the first occupant to move to the exit, plus the

time it takes all occupants to move through the exit door.

The first occupant in the simulation is approximately 2 meters from the exit door and has a velocity of

1.19 meter/second. That equates to a time of 1.7 seconds to reach the door. The exit time for the other

occupants is the number of persons divided by the effective flow rate times the effective door width.

There are 15 persons waiting to use the door, SFPE specifies an effective flow rate of 1.32

persons/meter*second for flow through a corridor, and since we specified a boundary layer thickness of

zero earlier in the problem, the effective door width is 1 meter. This equates to a door queue time of

11.4 seconds. The total expected SFPE egress time is then 13.1 seconds, which matches calculated value.

References (SFPE, 2003) Engineering Guide - Human Behavior in Fire. June, 2003. Society of Fire Protection

Engineers. 7315 Wisconsin Avenue, Suite 620E Bethesda Maryland USA 1-301-718-2910.