Effect of Recessed Sprinkler Installation on Sprinkler Activation Time and Prediction.
Effect of Recessed Sprinkler Installation on Sprinkler
Activation Time and Prediction.
(7112 K)
Madrzykowski, D.
Thesis; 158 p. 1993.
Keywords:
sprinklers; sprinkler response; building technology;
compartment fires; computer models; fire protection
engineering; gas burners; large scale fire tests;
sprinkler activation
Abstract:
The objectives of this study were to analyze the effects
of recessed sprinkler installation on sprinkler
activation time and evaluate the ability of sprinkler
activation models to predict activation time. Full
scale compartment fire tests were used to obtain
activation times for four different types of sprinklers.
The tests were conducted in an 18.9 m by 9.1 m by 2.35 m
high compartment using floor based fires with constant
heat release rates of 115, 155, 215, 290 and 520 kW.
Non-dimensional sprinkler radial positions, r/H, of 0.64
and 1.28 were evaluated. In addition to sprinkler
activation times, ceiling jet temperature, velocity and
radiation measurements were made. Comparisons of
activation times were made between sprinklers in a fully
exposed pendent position versus those in a 25 mm
recessed position. The 95% confidence limits for the
test data were developed and a thermal tenability
analysis was made to determine if the difference in
response times was significant with respect to life
safety. This analysis suggests that recessed
installation does not have an adverse effect on life
safety for the conditions tested. Several sprinkler
activation models were compared to the test data. A
modified sprinkler activation algorithm was developed
that includes hot gas layer effects to the ceiling jet
once the ceiling jet is fully developed.
Building and Fire Research Laboratory
National Institute of Standards and Technology
Gaithersburg, MD 20899