Apparatus for air conditioning or water production

An apparatus for cooling, comprising

• means for transport of fluid through a heating cycle
• an external heat source for heating the fluid in the heating cycle
• an expander with an expander housing having an inner side facing a first expander turbine inside the expander housing, and the expander housing having an opposite outer side, the expander having an expander inlet connected to the heating cycle for receiving fluid in a gas phase heated by the external heat source to drive the expander by expanding the fluid,
• a compressor with a compressor housing having an inner side facing a first compressor turbine inside the compressor housing, and the compressor housing having an opposite outer side, the compressor having 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 condenser for condensing at least one of the working fluid from the expander and the fluid from the compressor by energy transfer in a heat exchanger to a second fluid of lower temperature,
• an evaporator for evaporating the working fluid from the condenser by energy transfer from a third fluid in a further heat exchanger and for creating a desired cooling effect in the third fluid,
• wherein the external heat source is provided in thermal connection with liquid in a liquid buffer tank, and wherein the expander is provided inside the liquid buffer tank for transferring of heat to the expander housing by thermal contact of the liquid with the outer side of the expander housing.