An apparatus for cooling, comprising: a liquid pump for transport of fluid through a heating cycle, an external heat source for heating the fluid in the heating cycle, for example a solar heater directly connected to the heating cycle or connected through a heat exchanger, an expander with an expander inlet and an expander outlet, the expander inlet having a fluid connection to the external heat source for receiving fluid in the gas phase to drive the expander by expanding the fluid, a compressor with a compressor inlet and a compressor outlet, the compressor being driven by the expander for compressing working fluid from a low pressure compressor inlet gas to a high pressure compressor outlet gas, a first heat exchanger with a fluid connection to the compressor outlet and connected to the expander inlet for transfer of heat from the high pressure compressor outlet gas to the fluid in the heating cycle, a second heat exchanger with a condenser for condensing the working fluid from the expander by energy transfer to a second fluid of lower temperature, for example ambient air, a third heat exchanger with evaporator for evaporating the working fluid from the second heat exchanger by energy transfer from a third fluid and for creating a desired cooling effect in the third fluid. Particularly, according to the invention, the first heat exchanger is connected to the heating cycle between the external heat source and the expander inlet.