Normalized Heat Load Research Articles

Failure probabilities of constructions designed for fire resistance

Abstract‘Normalized heat load’ is a quantifier of the destructive potential of fires, real‐world compartment fires and test fires alike. For real‐world fires it is subject to some uncertainties owing to the random nature of two of the variables it depends on: ventilation and fire load. For test fires also it is subject to uncertainties owing to a moderate degree of randomness that characterizes the results of test fires. A procedure is described for predicting the failure probability in fire of the boundaries of a compartment designed for fire resistance on the basis of information concerning the characteristics of the compartment and the design value of the fire load. The procedure is essentially deterministic, employing statistical considerations only as far as required by the nature of some of the input variables. With the aid of second‐moment analysis, it is possible, furthermore, to design the compartment boundaries for appropriate target failure probabilities.

Effective thermal inertia in relation to normalized heat load

AbstractNormalized heart load, obtained by dividing heat absorption by thermal inertia, is a quantity useful in building design for relating fire severity in fully developed compartment fires to fire severity in standard fire resistance tests. Harmathy has shown how normalized heat load may be used for determining required fire resistance in projected buildings. The present work describes how effective values of thermal inertia can be calculated for such important materials as brick and concrete, both normal and lightweight, for which thermal properties depend strongly upon temperature.

Normalized heat load: A key parameter in fire safety design

AbstractIt is demonstrated that he normalized heat load is a suitable parameter for ranking various enclosure fires on a ‘potential for destruction’ scale. This parameter is convertible to the familiar fire resistance.

Assessment of fire resistance requirements

The calculation of normalized heat load, a succinct quantifier of the potential of compartment fires to spread by destruction, is greatly simplified by the introduction of two semi-empirical equations. These afford direct insight into the relation between the destructive potential of fire and the principal characteristics of the fire compartment and its contents of combustibles.