I intend to increase the temperature of the supply water in a FCU which was earlier designed for a 6deg supply and 12 deg return chilled water connection with a 10 deg supply and 18 deg return



What changes with respect to following needs to be incorporated
1. FCU Size. Will the Heat transfer surface needs to be increased. Or should it not be increased as the 'delta T' of 8 deg is achieved during transfer

2. Air flow. Is there any need for increase in Flow through the heat transfer surface. Or can this be achieved with increased heat transfer surface

1.I think the size of FCU should not be changed.
2. Same air-flow will give effect more quickly. Change in air-flow will only change the time to achieve the required temperature difference.