MS in Fire Protection Engineering
College of Engineering
Frederick Mowrer and Christopher Pascual
This report analyzes the fire protection systems of Engineering IV building at California Polytechnic State University, San Luis Obispo. It is a cumulative project of the Fire Protection Engineering Program at Cal Poly. The report consists of a prescriptive analysis and a performance-based design analysis. The building contains dry laboratories, classrooms, offices, and administrative spaces. The building is a three-story structure. There is an atrium that connects the first floor to the third floor. However, the building has a horizontal enclosure to separate the connection between the second floor and the third floor.
The prescriptive analysis is based on the code standards and regulations, which includes five subsections: means of egress analysis, structure analysis, fire alarm analysis, and sprinkler system analysis. The means of egress analysis section determines the occupancy load of each floor, occupancy capacity based on the door/stair width factor, common path, travel distance, and dead-end corridors. The structural analysis determines height limitations, number of story limitations, and area limitations based on the construction type of this building. The fire alarm analysis discusses detection devices application, notification devices application, and battery calculations for the system. The sprinkler system analysis discusses water source information, water demand curve, and design area. Overall, the Engineering IV building meets the code requirements and standard regulations.
The performance-based design establishes a computational fire dynamic simulation (FDS) to calculate the time to reach untenable conditions based on the assumed tenability criteria (smoke density, visibility, the temperature at 6 feet above the walking surface). The tenability criteria are referred from SFPE Handbook 5th edition. Pyrosim is utilized in the analysis to present a visual friendly output result and to determine the available safe egress time based on assumptions. Required safe egress time (RSET) is determined by an evacuation model (hand calculation) and the results are compared to ASET. Three design fire scenarios are selected in this report based on recommendations of NFPA 101, Chapter 5. The first design fire scenario is a typical office catching on fire. The consequence of the office fire is smoke spreading to a corridor which may cause occupants to get stuck in a corridor. The ASET for this design fire scenario is 385 seconds, which is greater than RSET. The second fire scenario is selected in the atrium. Smoke spread into a large open space may delay the time to detect the fire. As a result, it will raise the risk for occupants to evacuate the building within a safe time. The result shows that ASET is 355 seconds and RSET is 343 seconds. The last design fire scenario is in a lab with a large fuel load. In this report, it discusses the possibility of people getting stuck in the compartment and corridor. Based on the assumptions, the result indicates that ASET is greater than RSET. Therefore, all three design fire scenarios proves that the fire protection system design in this building is adequate for occupancy to evacuate before the time reaches untenable conditions. In one of the design fires, ASET is only slightly greater RSET and the safety factor is close to 1, which may challenge occupant’s life safety. But Stair 3 in the atrium may be used for means of egress at the beginning of the fire. Even though it is not designed for evacuation, it can decrease overall evacuation time by avoiding queuing on the second floor.