The move towards a low-carbon world, driven partly by climate science and partly by the business opportunities it offers, will need the promotion of environmentally friendly alternatives if an acceptable stabilisation level of atmospheric carbon dioxide is to be achieved. This requires the harnessing and use of natural resources that produce no air pollution or GHGs and provides comfortable coexistence of humans, livestock, and plants. GSHPs are receiving increasing interest because of their potential to reduce primary energy consumption and thus reduce emissions of GHGs. The main objective of the research is to stimulate the uptake of the GSHPs. This paper describes the details of a prototype direct expansion GSHP test rig and details of the construction and installation of the heat pump, heat exchanger, heat injection fan and water supply system. It also presents a discussion of the experimental tests currently being carried out.