Comparative data shows mass loss, heat flux, and damage pattern to gypsum wallboard exposed to a wood crib fire.

Technical Report on Heat Transfer and Fire Damage Patterns on Walls Released by FSRI

September 4, 2024

The Fire Safety Research Institute (FSRI), part of UL Research Institutes, in collaboration with the Bureau of Alcohol, Tobacco, Firearms and Explosives Fire Research Laboratory released the technical report Measurement of Heat Transfer and Fire Damage Patterns on Walls for Fire Model Validation. The report is part of the Heat Transfer and Fire Damage Patterns on Walls for Fire Model Validation research project that was funded through a grant from the National Institute of Justice.

Heat Transfer and Fire Damage Patterns on Walls Exposed to Fire

Fire models may be used by fire investigators to make predictions of fire dynamics in structures. However, suitable data for validating fire model predictions of heat transfer and fire damage patterns on walls exposed to fires is limited. Since mass loss and discoloration fire effects are related to heat transfer and thermal decomposition of walls, this report provides a novel dataset for validation of fire models addressing these topics.

The report details the measurements and findings from a series of experiments that address three validation spaces: thermal exposure to walls, heat transfer within walls, and fire damage patterns on walls. A total of 63 experiments were conducted, encompassing seven fire sources and three wall types (each combination in triplicate). Fire sources include a natural gas burner, gasoline and heptane pools, wood cribs, and upholstered furniture. Three types of walls were used to address the three validation spaces:

  • A calcium silicate board (CSB) wall was used to address the heat transfer through walls validation objective. Heat flux and surface temperatures were measured in these experiments.
  • A gypsum wallboard (GWB) wall was used to address the fire damage patterns validation objective. Discoloration and mass loss fire effects were measured in these experiments.
  • A steel wall (in the form of a plate heat flux sensor of equivalent area to the CSB and GWB walls) was used to address the heat transfer to walls validation objective. The plate temperature and gas temperatures on both sides of the sensor were measured in these experiments.

Research Findings

This study revealed that the cumulative heat flux over the surface of a fire-exposed GWB wall was not consistent with the observed discoloration and mass loss fire effects. On the other hand, a distinct relationship was found between mass loss and discoloration fire effects, and it was determined that lines of demarcation between charred and un-charred regions of the fire-exposed wall coincided with a mass loss ratio of 14.9 ±2.1% for the GWB considered. This study revealed a pathway for fire investigators to relate fire model predictions (mass loss occurring in a GWB wall, driven by thermal decomposition of the material) to physical evidence collected in an investigation (discoloration fire damage patterns). The dataset from this project is available in a public repository, and is expected to be leveraged in future validation studies.

“This research has produced a novel dataset encompassing heat transfer and fire damage patterns on walls exposed to fires. By measuring heat flux and mass loss fields over the surface of gypsum wallboard, we have identified key relationships between fire exposures and discoloration and mass loss fire effects.”
—Matt DiDomizio, lead research engineer, FSRI

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Research Project: Heat Transfer and Fire Damage Patterns on Walls for Fire Model Validation
Report Title: Measurement of Heat Transfer and Fire Damage Patterns on Walls for Fire Model Validation
Report Authors: Matthew J. DiDomizio and Jonathan W. Butta, P.E.
Download the Report: https://dx.doi.org/10.54206/102376/HNKR9109
Release Date: September 4, 2024
This report may be cited as follows: M.J. DiDomizio and J.W. Butta, Measurement of Heat Transfer and Fire Damage Patterns on Walls for Fire Model Validation, Tech. Rep., UL Research Institutes, Fire Safety Research Institute, Columbia, MD, 2024.

This research was supported by Award No. 15PNIJ-21-GG-04167-RESS, from the National Institute of Justice, Office of Justice Programs, U.S. Department of Justice. The opinions, findings, and conclusions or recommendations expressed in this publication / program / exhibition are those of the author(s) and do not necessarily reflect those of the Department of Justice.

Heat Transfer and Fire Damage Patterns on Walls for Fire Model Validation

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