Evaluating the Transient Radiant Heat Flux Impacts to Occupied Buildings

Abstract

Traditional methods of evaluating radiant heat impacts on occupied buildings typically rely on a threshold radiant heat flux value to evaluate occupant vulnerability. While this is acceptable within the methodology of fire hazard evaluation presented in the API RP 752 standard, the approach does not account for structure properties, the transient nature of the fire, or duration of exposure. These factors are an important part of describing the potential impact on occupied buildings, as well as the vulnerability of the building’s occupants. Because API RP 752 does not provide any specific guidance on these topics, the specific evaluation of a building and its response to thermal radiation is left to the analyst. Previous work applied first principle numerical tools to define the impacts from continuous external fires. This paper continues that work to evaluate transient thermal loading on the building exterior and heat transfer through the building materials to better determine building occupant vulnerability. This work will help to define the limits of radiant heat dose for occupied buildings that may be exposed to external fires.