The problem of removal of combustion products during the reconstruction of existing boiler houses is considered. The issue of determining pressure losses due to friction in steel and brick gas ducts when performing an aerodynamic calculation of gas ducts from gas-fired boilers is considered. Nomograms have been developed that make it possible to determine the specific pressure loss depending on the volume of flue gases and the diameter of the gas ducts.

Keywords: reconstruction, boiler units, aerodynamic calculation, friction pressure losses, gas ducts