This paper describes the development of a Mobile Air Conditioning (MAC) system with a very small impact on the environment. The system based on adsorption cooling is powered by the waste heat recovered from the engine coolant. The advantages of such a system are: a drastic reduction of the fuel overconsumption and the CO2 emission associated to the MAC usage, and the use of water as the refrigerant, which is a no Global Warming Potential (GWP) fluid  compliant with the new EU regulation and naturally available. In addition the system being based on thermal compression and not on mechanical compression, is decoupled from the engine operation and has no impact on the vehicle handling. Finally, coupled with a small fuel burner or with a solar panel it can provide air conditioning when the vehicle engine is stop. Thus the system can provide the cabin preconditioning and allows the cabin cooling for those vehicles which are also used for rest or sleeping (truck, camper). The core of the system is an adsorption chiller that has been designed, manufactured and tested at first at the ECN laboratory. It produces 2 kW of chilling power with a COP of 0,4. The on board overall MAC system has been designed, manufactured and installed on a Fiat Grande Punto at CRF. The testes demonstrate the potential of such device to replace conventional vapor compression system. Following this experimental work a system redesign and car integration study was done and showed the potential to further reduce the volume and weight of the adsorption cooling system to the extent that the system can be integrated fully in the engine compartment.