MS in Fire Protection Engineering
College of Engineering
Frederick Mowrer and Christopher Pascual
The Jack E Brown Chemical Engineering building at Texas A&M is located in College Station, TX. While this building is dedicated to chemical engineering, it serves many different departments as they use the lecture halls on the first floor. It was built and opened in 2004 and has 206,500 square feet with 7 stories. The building consists of multiple labs as well as study hall rooms, computer labs, offices, and the normal MEP/storage rooms. Jack E Brown building is one of the foremost buildings of the Texas A&M engineering quadrant and is further proof that Texas A&M desires to keep leading out on the engineering front. This is one of the busiest buildings on campus and with a wide range of room usages, an in-depth analysis of the building components as it relates to fire protection and life safety will be completed prescriptively for compliance. This prescriptive based analysis covers egress, fire alarm, fire suppression, structural, and flammability requirements to analyze compliance with the International Building code (IBC) and governing NFPA standards.
The first portion of the analysis relates to the egress components which mostly comply for this building. There are a sufficient number of exits in this building, but the occupant calculations determine there are too many occupants on the 3rd through 6th floors. The building has only two exits on the upper floors, but they are separated by more than one-third the overall length of the building and meet the requirements for exit separation. Travel distances, dead end corridor lengths, and common paths of travel are all within the limitations required by NFPA 101. Exit signs are the other component of the egress analysis which are determined to be located in accordance with the requirements
The fire alarm system provides detection and notification per NFPA 72 throughout the building as required at the time this building was built. This building does not have a mass notification system, but it was not required at the time of construction. The average ambient sound level for an educational occupancy is 45 dBA and 55 dBA for a business occupancy. It appears from the plans that the requirement for sound levels to be at 15 dB greater than ambient would be met based on the locations of the placed devices. The power supply is analyzed per the requirements of Texas A&M and appears to be in accordance. A summary regarding the inspection, testing, and maintenance requirements are provided. Overall, there are no major issues with the fire alarm system from the prescriptive based analysis.
The water-based fire suppression system in the building is installed per NFPA 13 as a wet pipe sprinkler system with an automatic standpipe. The hydraulic calculation for the system is driven by the demand of the automatic standpipe system which requires 100 psi at the most remote hose valve and 750 GPM total. The water supply from the city was insufficient to meet the standpipe system demand and a fire pump was installed. The fire pump installed was rated for 750 GPM at 100 psi and was found to be adequate for the sprinkler system and standpipe demand based on NFPA 20 requirements. The hydraulic calculations performed for the sprinkler system were also found to be compliant with NFPA 13 utilizing both light and ordinary hazard occupancies. The combined sprinkler/standpipe system is required to be inspected, tested, and maintained per NFPA 25 which is summarized in the analysis. In addition to the sprinkler system, there is an FE-13 clean agent system provided in the chemical storage room on the first floor. The fire suppression components within this building appear to be in accordance with the appropriate codes and standards.
The structural fire protection analysis identifies the building as Type IB and confirms that the design is in accordance with restrictions placed on Type IB buildings per IBC. The number of stories, height, occupancy types, and area are all confirmed to be within code regulations. The IBC also outlines requirements for separation of occupancies and the first floor of the Jack E Brown building is a mixed occupancy requiring a 2-hour fire wall to separate between the lecture halls (educational occupancy) and the remainder of the building (business occupancy). The building components are also analyzed with the requirements for each identified per the code. The resources were not available to confirm the compliance of each of these items, but it is assumed that they comply with the code. Flammability requirements are outlined for the building requirement based on time of construction, but the details were not available to confirm that the installation complied.
A performance-based design is also discussed to compare available safe egress time vs required safe egress time. This design is based on the goals and objectives provided in NFPA 101 and considers three different fire scenarios for the Jack E. Brown building. The first fire considered is in the first-floor lecture hall and is analyzed for both sprinkler detector response time and structural failure. With the fire resistance ratings applied to the structure, there is no structural failure for this area based on the fire scenario. The second fire scenario is for an office space on the seventh floor that would be affected by the exterior windows present in this space. This design fire is important to analyze since the door opens directly to the exit corridor and could be detrimental to occupants in the area. The third and final design fire is in one of the laboratories on the 4th floor adjacent to the exit stairwell. This fire is chosen since this fire would be the most severe fire affecting occupants in this building. Along with the fire analysis, a building model is completed to determine the tenability conditions presented by design fire three.
The available safe egress time is the amount of time between ignition and when circumstances become untenable. Tenability conditions presented in this analysis and discussed include visibility, temperature, and carbon monoxide exposure limits. Each one of these criteria are analyzed utilizing the Fire Dynamics Simulator and Smokeview models. The visibility in the exit corridor becomes untenable just before two minutes due to the initial growth of design fire three but when the fire stabilizes, the visibility is at a level which would be tenable. The temperature is extreme inside the laboratory and reaches untenable conditions within the first two minutes, but the hallway remains tenable throughout this time. Beyond the moment in which the heat release rate stabilizes, the temperature in the hallway remains tenable for all occupants. The third condition analyzed using FDS and SMV is the CO exposure which does not exceed the tenable conditions at any point throughout the model.
With the available safe egress time determined, the required safe egress time is calculated to confirm that occupants have enough time to egress. The required safe egress time is approximately 24 minutes when calculated by hand. In addition to the hand calculations, results from Pathfinder, a computer-based egress modeling system, are presented as 23 minutes and 24 seconds for total egress.
The conclusion for the performance-based analysis is that the Jack E Brown building, as constructed per the appropriate codes and standards, provides a large enough available safe egress time to allow all occupants to exit the building. This remains true as long as the building is maintained, and inspections are completed as required. A fire safety management plan is included at the end of this report to provide insight for the building owner on how to maintain the building to ensure the best chance of survival for occupants in the event of a fire. In addition to the fire safety management plan, it is recommended that all self-closing doors are properly functioning, and that staff is trained to allow these doors to close instead of propping them open. It is also recommended that a mass notification system is installed in the building as this was not required when the building was constructed but is required per codes today. This system would provide an additional level of safety for the occupants.