This paper is concerned with testing an absorption-recompression chiller using water/potassium formate (H2O/HCOOK) as the working fluid. A limitation of current conventional absorption chillers is that they can be used only with a few refrigerant/absorbent combinations, principally water/lithium bromide. Concentrated lithium bromide solutions have a relatively high crystallisation temperature and can solidify or “freeze” inside the chiller unit. They are also corrosive to metals and very expensive. Many different refrigerant/absorbent combinations have been cited in the literature, but these have similar disadvantages to water/lithium bromide solution. This paper evaluates the performance of a new working fluid namely, water/potassium formate (H2O/HCOOK). The physical properties of potassium formate carry many benefits, i.e. it is less corrosive, less expensive to manufacture, and has a lower density and viscosity than absorbents such as lithium bromide. A small-scale chiller was constructed and tested in the laboratory. Experimental work was carried out using conventional refrigerant/absorbent combinations such as water/lithium bromide (H2O/LiBr).