To provide an air conditioning system for improving fuel efficiency.

This air conditioning system 1 includes a solar water heater 10 for heating water by solar heat, and an absorption type refrigerating machine 20 for obtaining cold water to be used in an indoor unit 30 by a circulation cycle of an evaporator 21, an absorber 22, a regenerator 23 and a condenser 24. The solar water heater 10 supplies warm water obtained by heating, to a hot water supply type refrigerating machine 20. The absorption type refrigerating machine 20 absorbs a refrigerant evaporated by the evaporator 21 by absorbing liquid in the absorber 22, supplies the absorbing liquid having absorbed the refrigerant, to the regenerator 23, and heats the absorbing liquid to be supplied from the absorber 22 to the regenerator 23, by the warm water from the solar water heater 10.