Comparison Testing Protocol for Firebrand Penetration through Building Vents: Summary of BRI/NIST Full Scale and NIST Reduced Scale Results
Samuel L. Manzello, Seul-Hyun Park, John R. Shields, Yoshihiko Hayashi, Sayaka Suzuki
An ASTM task group on vents, organized within Subcommittee E05.14.06, External Fire Exposures, has developed a reduced scale test method (not presently a standard) aimed at evaluating the ability of vents to resist firebrand intrusion into attic and crawl space areas. In the ASTM test method, firebrands are produced by igniting wood pieces and the firebrands are subsequently deposited on top of the vent installed in the test chamber. The vent is placed horizontally in the apparatus and air is pulled through the vent using a fan placed downstream. The mechanism of firebrands residing on top of vents and being pulled down onto vents is not actually seen in practice. In reality, the firebrands are actually blown onto the vents themselves. Therefore, a comparison testing protocol was undertaken, with the formal support of the ASTM E05.14.06 task group, between the methods developed by ASTM to full scale experiments using the NIST Firebrand Generator coupled to the Fire Research Wind Tunnel Facility (FRWTF) at the Building Research Institute (BRI) in Tsukuba, Japan. The BRI/NIST full scale experiments attempt to replicate a wind driven firebrand attack that is seen in actual fires. NIST has also developed a reduced scale test method aimed at investigating firebrand penetration through building vents that consists of a reduced scale Firebrand Generator (Baby Dragon) coupled to a bench scale wind tunnel. The newly developed NIST reduced scale test also replicates a wind driven firebrand attack. This comparison testing protocol will determine if the reduced scale methods (ASTM and NIST reduced scale test method) are able to capture the salient physics of firebrand penetration through building vents observed using the full scale test method. Experiments conducted by NIST in support of this comparison testing protocol are presented and discussed.
, Park, S.
, Shields, J.
, Hayashi, Y.
and Suzuki, S.
Comparison Testing Protocol for Firebrand Penetration through Building Vents: Summary of BRI/NIST Full Scale and NIST Reduced Scale Results, Technical Note (NIST TN), National Institute of Standards and Technology, Gaithersburg, MD, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=904793
(Accessed October 2, 2023)