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malcopate
23-05-2012, 03:26 PM
Should chilled water pumps be pumping thru the Chiller coil or sucking from it, which is better and why?

Yuri B.
23-05-2012, 06:17 PM
The first variant - on the most installations I have seen.

The idea behind having the pumps upstream of the chillers is to ensure that there is always a positive head on the chiller heat exchanger. There should be as little restriction as possible between the last coil and the suction side of the pump to ensure that the net positive suction head available (npsha) always meets or exceeds the net positive suction head required (npshr) of the pump. This is greatly simplified, but most conventional systems are designed this way. I have seen lots of other variations.
Said the user Tech Rob on the HVAC-Talk forum