Preliminary experimental investigation into the influence of bends on the thermal and hydraulic performance of domestic flues.

Because of the lack of valid information regarding the influence of bends on the thermal and hydraulic performance of flues, a series of preliminary experiments were conducted using a full-scale Perspex rig. Analysis of the results and observations enabled the development of a methodology capable of determining the reduction of flow rate arising from the presence of bends. The analysis has also shown that existing quasi-steady-state methods used for the design of these flue systems are valid. Consequently, it is possible to determine flue gas and flue wall temperatures with respect to height within a flue system containing bends operating under low bum rate conditions.