Single-phase ‘shaded-pole’ induction motors, which are commonly employed for driving small (i.e. <0·25-m diameter) tube-axial fans, are characterised by end-use efficiencies of less than 20%. However, electronically commutated (i.e. ‘brushless’) permanent-magnet, low voltage, DC motors achieve significantly greater efficiencies (e.g., typically exceeding 40%) when used for the same purpose. Although for air-moving applications, the popularity of brushless DC motors has been limited by their high manufacturing costs, the ready availability of monolithic, specific-purpose, integrated circuits now permits the development of designs which offer cost-effective alternatives to conventional low power-output (<100-W) AC, as well as DC, motive systems. In particular, a dsign of a low-cost brushless motor for driving a standard tube-axial fan, of 0·115-m diameter, is described: it is optimised so that the least cost per unit of mass production ensues. This fan unit achieves an 80% reduction in the rate of energy consumption and a 52% saving in weight, when compared with its AC counterpart of nominally identical performance. Further improvements in its efficiency (e.g. from 44% to 53%) are attainable, for relatively small increases in manufacturing cost (e.g. <5%).