Chilled Systems Advice/Calculations

Hi,

I have a few questions regarding a chilled water system.

How can I determine the Cooling Capacity required for a room? (Data Centre) In tons.

Also, how can I determine the optimum flow of water across the evaporator in the room? is there a set water flow/fan speed calculation or graph.

The temperature difference between chilled water temperature at chiller and the 'in room' evaportator temperature? for example for a AC system its about 10K difference - is that the same with chilled water systems?


Any information would be greatly appreciated - thanks