This part of ISO 10294-5 describes the test requirements related to intumescent fire dampers. It identifies the minor modifications needed to adapt the test method described in ISO 10294-1 (which was intended for mechanical dampers) to suit intumescent fire dampers. Additional tests are included to give an assessment of the operational reliability of intumescent fire dampers. This test is intended for intumescent fire dampers that are expected to be classified as EI dampers in accordance with ISO 10294-2. Without the addition of a mechanical damper, they are unable to achieve the “S” classification, which includes a leakage limit imposed at ambient temperatures.