Abstract: An absorption chiller includes a boiler with a vessel for storing a working fluid and a heat source configured to heat the working fluid. A first device is configured to cool the working fluid, and a second device is configured to cool the working fluid. A flow path is arranged to enable the working fluid to flow from the boiler through the first device, through the second device and back to the boiler. A first waste heat source is generated by the first device when cooling the working fluid. The first waste heat source is configured to heat the working fluid along the flow path after exiting the second device and prior to re-entering the boiler.