LAUSR

Abstract Fires in residential buildings originating in flue ducts pose a significant problem in Europe, especially in countries where heating systems rely on devices fired with solid fuel. The high temperature of fumes emitted from heating devices is a main cause of fires. In the case of soot fires, the risk increases, as the temperature in the flue duct can exceed 1000 °C. Chimneys are often located close to flammable (wooden) construction materials, which further increase the risk of fire. This article presents statistical data confirming the significance of the problem. The subject of this study is fire safety of a three-layer chimney system. The diameter of the flue duct of the inspected chimney was 180 mm, while air space and insulation measured 30 mm. The main research involved the use of thermocouples and a thermal imaging camera. The analysed chimney is an innovative construction, as it is equipped with an additional insulating air layer. The purpose of the research is to assess the impact of this air layer on fire safety during the use of a three-layer thin-walled flue pipe. The air space discharges heat from the flue duct through a parallel flow of cold air. Analysis explored the impact of the chimney's thermal radiation on unprotected and easily flammable construction materials. Particular attention has been devoted to the impact the air layer has on reduction of the amount of thermal radiation. Final conclusions from the study can be used to increase fire safety of residential buildings. This may be achieved by reducing temperatures emitted from the chimney cladding.