Thermal Breakage of Double-Pane Glazing by Fire.
Thermal Breakage of Double-Pane Glazing by Fire.
(951 K)
Cuzzillo, B. R.; Pagni, P. J.
Journal of Fire Protection Engineering, Vol. 9, No. 1,
1-11, 1998.
Sponsor:
National Institute of Standards and Technology,
Gaithersburg, MD
Keywords:
glazing materials; cracking (fracturing); windows; heat
transfer; equations; convective heat transfer
Abstract:
A model for double-pane window breakage due to heating
by fire is developed that applied to both compartment
fires and to urban/wildland intermix fires. This work
builds on the model and computer code, BREAK1, for
single-pane window breaking by fires, as described in
previous publications, with additional features
including the inter-pane gap heat transfer and
sequential pane-breaking. A Mathcad-based computer
code, McBreak, is developed that implements the
double-pane model. Radiation is shown to dominate the
inter-pane gap transport unless low-emissivity interior
glass surfaces are used. Fires on the outdoor side of
double-paned windows are included, since windows
represent one of the most vulnerable features of
dwellings in the urban/wildland intermix and
double-paned windows help fire-harden a structure.
Examples are presented for double-pane window breakage
in compartment fires and wildland fires. Confirmed is
the empirical observation that double-pane equipped
structures might survive urban/wildland intermix fires
better than their single-pane equipped neighbors.
Building and Fire Research Laboratory
National Institute of Standards and Technology
Gaithersburg, MD 20899