Lessons learned from a reappraisal of the original heatpump.

This paper examines the concept presented in 1852 by Professor William Thomson of Glasgow University for heating and cooling buildings by currents of air. This was the first time that the use of a heat pump was discussed in an academic paper. Thomson’s system is described and his performance calculations are scrutinised in SI units (they are presented in “inch-pound” units in the original paper). The practicality of the proposed system is considered and the performance claims made for it are tested against current thermodynamic understanding and compared to modern systems. Some aspects of the concept are shown to be impractical but there are several important lessons to be learned from the approach taken which are relevant to the challenge of justifying the adoption of heat pumps in modern systems.