Chilled water system - pump head

[Hassanakhlaq]

While calculating the pump head in a closed loop chilled water system, we need to determine the total friction losses that a pump is supposed to overcome in the piping loop.For this purpose only supply line upto the coil (AHU / FCU etc) should be taken in account or return line from coil back to the pump should also be considered.Or in other words equivalent length of the critical path comprises of both supply and return piping length or only length of the supply line upto the coil.Thanks

 

[DRWeig]

Hassanakhlaq,

All pipe will have water flowing thru it from the pump -- so all pipe must be counted (supply plus return).

Don't forget the coil and control valve drops, and if you're using balancing valves, they need some DP also.

Good on ya,

Goober Dave

 

[kepharda]

DRW is right, you need to take both the delivery part and the return circuit into consideration.

Also consider that if there are multiple "loops" possible serving different cooling coils, ensure you are analyzing the one that has the largest head loss, this is typically the longest or the furthest away from your pump.

this message has been approved for citizen to elect kepharda 2008