Abstract: Disclosed is an air cooling system for cooling a room at lower operational cost. In one aspect, the air cooling system comprises a primary water cooling system for cooling water based on a vapor compression refrigeration methodology and a secondary cooling system for cooling a room utilizing the cold water. The primary cooling system further comprises a liquid line coil for cooling the water based on heat transfer. Further, during operation the liquid line is configured to receive a liquid refrigerant. The secondary cooling system further comprises a container containing water, a pump and an evaporator for cooling ambient air in a room. Further, during operation the water in the container is cooled due to the liquid refrigerant flowing liquid line. Upon cooling, the cold water is pumped by the pump into the evaporator for cooling a room.