Fire Safety Science Digital Archive

In performance-based fire safety design for means of egress, t-squared heat release rates have been used as design fires. In order to estimate fire growth rates in office rooms, eleven full-scale fire experiments were conducted for typical office arrangements. They included cases with and without suppression. Typical office arrangements were modeled based on fuel load surveys in contemporary office buildings. The results of experiments clarified that: 1) fire growth in office rooms largely depends on the combustion of plastic materials, which are commonly used in office fuel packages; and 2) In the case of quick response sprinkler operation, HRRs continued to be approximately 200 kW during suppression. We estimated fire growth rates for all experimental cases by modeling the t-squared fires and examined the effects of parameters on fire growth rates. We compared the results of experiments with several design fires in the engineering design guidelines and discussed design fires for office buildings. Fire growth rates for office desk units range from 0.007 to 0.017 kW/s², that are close to the ‘medium’ fire growth in NFPA 92B. Heat release rate curves with suppression are almost included within the design fire that was proposed by Lougheed, even if only one sprinkler head was activated.