1.1 The requirements in this International Standard govern the application of explicit algebraic equation sets to the calculation of specific characteristics of ceiling jet flows. 1.2 This International Standard is an implementation of the general requirements provided in ISO/TR 13387-3 for the case of fire dynamics calculations involving sets of explicit algebraic equations. 1.3 This International Standard is arranged in the form of a template, where specific information relevant to algebraic ceiling jet flows equations is provided to satisfy the following types of general requirements: a) description of physical phenomena addressed by the calculation method; b) documentation of the calculation procedure and its scientific basis; c) limitations of the calculation method; d) input parameters for the calculation method; e) domain of applicability of the calculation method. 1.4 Examples of sets of algebraic equations meeting all the requirements of this International Standard are provided in separate annexes to this International Standard for each different type of ceiling jet flow. Currently, there is one informative annex containing algebraic equations for quasi-steady state, axisymmetric ceiling jet flows.