ISO 21925-2:2021

This document specifies a test method for the determination of the resistance of fire dampers to heat, and for the evaluation of their ability to prevent fire and smoke from spreading from one fire compartment to another through an air distribution system.
This document describes the test requirements related to intumescent fire dampers. It is intended for intumescent fire dampers that are expected to be classified as EI dampers. Without the addition of a mechanical damper, they are unable to achieve the “S” classification, which includes a leakage limit imposed at ambient temperature.
This document is not intended to be used for dampers used only in smoke control systems, for testing fire protection devices which only deal with air transfer applications, or for dampers used in suspended ceilings, as the installation of the damper and duct can have an adverse effect on the performance of the suspended ceiling, requiring other methods of evaluation.
NOTE       "Air transfer" is a low-pressure application through a fire separation door (or wall, floor) without any connection to an air duct.