A Framework for Selecting Design Fires in Performance Based Fire Safety Engineering

In fire safety engineering, the concepts of design fire scenarios and design fires are important for several reasons. In the design phases of a construction project the performance of safety measures, and the potential consequences of a fire, must be assessed by exploring design fire scenarios and design fires. Active and passive fire safety measures are dimensioned by exposing the systems to predetermined fire events. A predetermined fire event can also be used to extract fire-related quantities, such as smoke production rates, temperatures, and heat fluxes. Therefore fire events, which form the basis of these analyses, must be established. In this paper we report results from our investigation of current approaches used to determine design fires and their associated input variables. We present a framework to categorize design fires based on various engineering principles, in which fuel properties and environmental factors are emphasized. The framework provides a more consistent methodology than seen elsewhere, taking the perspective of the practicing engineer into account. Furthermore the creation of design fires encompasses considerations of uncertainty and validity.