The engineering maintenance staff at a large hardware manufacturing plant were constantly suffering from failures of the air conditioning units throughout the warmer months. Although the air conditioning system was large with an adequate reserve the secondary cooling system was too small which resulted in short operating periods as the AC quickly cooled the system and cut out at the low temperature setting. The cooled water which served the individual room chillers quickly warmed which called on the compressors for further service.RAH Consultancy was approached to consider the operational requirements for the units and suggest options. The system was found to operate through a low loss header transfer system and RAH advised that the size of the stored water be increased by a large factor so as the increase the operational load and decrease the number of stop/starts that were stressing the system. The calculations for the water storage and operational times were provided to our client.