The paper presents the results of an experimental study of heat transfer and friction inside a circular tube containing a number of different turbulence promoters, among which is a novel device developed from earlier work on thermosyphons. (1) Measurements of the local and average heat transfer rate and pressure drop were taken across the test section. The results show a maximum local Nusselt number at a point 1 to 2 diameters downstream of the device. This is in keeping with the results from conventional promoters. Further downstream, i.e. beyond 10 diameters, all promoters were found to produce only a small increase in heat transfer. The average heat transfer rate and the friction factor were noticeably higher in the presence of a promoter.