MS in Fire Protection Engineering
College of Engineering
Frederick Mowrer and Christopher Pascual
This report provides an in-depth analysis of the fire safety systems and design considerations of the Costco store located at 450 10th Street in San Francisco, California, satisfying the requirements for completion of the FPE 596 – Culminating Experience in Fire Protection Engineering academic series. The building is introduced, followed by an analysis of the building structure, alarm and detection, egress, and sprinkler systems are designed based on prescriptive code. These systems are then analyzed from a performance based perspective to gain understanding of how the systems will respond to a challenging design fire. Their response is used to determine if the building is compliant with requirements of performance based design.
The Costco store is a large warehouse style building of mixed occupancy. The fully sprinklered 122,000 sq. ft. building is of noncombustible construction and is used for multiple occupancies. The primary occupancy of the large, warehouse-style building is for mercantile purposes. As seen in Figure 1, the store features an open floor plan with goods such consumer electronics, clothing, home, office, and work supplies, fresh and packaged foods and beverage are stored throughout the store in floor display and high piled rack storage orientations. Office, kitchen, and dining occupancies constitute a portion of the building, along with some areas designated service occupancies as shown in Figure 2.
The study begins with an introduction to the structure of the building. Occupancy classification is determined, which combined with height and area data is used to determine allowable types of construction and the materials used. An array of prescriptive codes is examined and the structure of the building is found to be acceptable. After the structure of the building is fully explored, the life safety systems that impact occupant safety during a fire are discussed.
An alarm and detection system is designed for compliance with prescriptive code. The alarm and detection section first identifies components used in the system, such as heat detectors, horn- strobes, and the fire alarm control panel. The locations of the system components are presented, and the expected response of the system to a fire is calculated. Adequate backup power is provided and maintenance of the system is established. Application of a Voice Alarm Communication Systems (EVACS) is considered but deemed unnecessary.
After the alarm and detection design, the Costco is analyzed for its ability to allow for safe egress of occupants. The maximum occupancy of the building is determined, and the number, size, and location of exits are evaluated with consideration to the expected demographics of the store. Expected evacuation time is calculated, and tenability of occupants in a fire environment is discussed. 7
Once egress is investigated, a sprinkler system is designed with the goals of reducing the risk of harm to life and property. The sprinkler system components are discussed and the systems are laid out based on the occupancy and materials found the building. The hydraulic demands of the systems are calculated using hand calculations and sprinkler system modeling software, followed by a discussion of inspection, testing, and maintenance protocol. Recommendations are made to improve the sprinkler system performance.
With these life safety systems designed and analyzed from a prescriptive approach, their effectiveness is put the test using performance based design. In the fire scenario, an ultra-fast growth rate fire with high heat release rate and output of toxic gases, based on full-scale testing of electrical equipment similar to that found in the Costco, is located in front of the main exit from the building, blocking its use. The Costco is filled to maximum occupancy. The required safe egress time of 5.5 minutes is demonstrated to be less than the available safe egress time, based on the height of the smoke layer filling the store.
Recommendations are then made for furthering the research of this report and exploring other design fires and performance criteria.