ESDU 79037 gives information to assist the specialist and non-specialist in fan selection and tender appraisal. For the non-specialist, the special terminology appropriate to fans is introduced, the types of fan available and their typical performance characteristics are reviewed, the requirements of a system are outlined in terms of stability, flexibility, growth potential, need for stand-by, and other factors, and the choice of a fan to match those requirements explained. Then, for specialist and non-specialist, a selection procedure is developed that enables the impeller power, speeds and maximum dimensions for a given duty to be estimated. A method of predicting the sound power spectra generated is also given, together with general guidance on the presentation and use of noise data. The specification of electric motors for fans is considered, covering the characteristics of the various types and those features of particular relevance to the application. A practical worked example illustrates the use of the procedures.