The Hilton Concentric Tube Heat Exchanger has beca'designed specifically to demonstrate the working principles of industrial beat exchangera in the most convenient way poesible in the laboratory classroom. The apparatus requires only a cold water supply, fused electrical supply and a bench top to enable a series of simple measurements to be made by students noeding an introduction to heat exchanger design and operntion. Experiments can be readily conducted in a short period of time, with virtunlly no setting up operations, to nccurately show the practical importance of the ollowing