Chillers are designed to operate with a minimum water volume, which typically ranges from 22 litre to 38 litres per ton for air conditioning application, for to get better temperature accuracy. Most of the chiller compressors can only start 3 to 4 times per hour. If the compressor is off and if there is a demand for chilled water the compressor cannot get on immediately. Without chilled water, building will not get the required cooling. To solve this problem chilled water buffer vessels are added in the system. These tanks increase the capacity of the chilled water in the system and stabilize the return.