Dual Pumps: what arrangement is better

[Fir3^StorM]

hi,
I have just wondered what arrangement would achieve the max flow and performance.
I'm not WCing at all (but im planning in future), just want to know ;)

dual pumps in series - one after another, like this:
Res -> Pump -> Pump -> Rad -> CPU -> GPU -> NB -> Res

or dual pumps like this:
Res -> Pump -> Rad -> CPU -> Pump -> GPU -> NB -> Res

thx

[spin_doctor]

In theory those two setup's shouldn't be any different as far as flow goes...

However (again in theory), as the pumps are in series you won't achieve any higher flow rate than a single pump, rather you'll increase maximum head.

Pumps in series: No increase in flow. Increase in head.

Pumps in parallel: No increase in head. Increase in flow.

[Graystar]

Doesn't matter where you put the pumps.

Increasing head does increase flow.

Series = 17% increased flow.

Parallel = itty bitty increase in flow.

See Petra's test, which include a series vs. parallel test at the end.
http://www.xtremesystems.org/forums/showthread.php?t=117215

[Fir3^StorM]

okay, thanks :)

[Sneaky]

Doesn't matter where you put the pumps.

Increasing head does increase flow.

Series = 17% increased flow.

Parallel = itty bitty increase in flow.

See Petra's test, which include a series vs. parallel test at the end.
http://www.xtremesystems.org/forums/showthread.php?t=117215



putting pumps in series is not made to increase flow, even though it does somewhat - putting pumps in series adds about 1.5 times the head from a single pump, so it gives the loop more pressure, and thus a more consistent flowrate that won't drop off as easily in the system

running pumps in series is great for larger multi-block or restrictive systems


so just put them pump > pump, thats the best way to do it, and probably the easiest way to route tubing as well :toast:

[Fairydust]

...putting pumps in series adds about 1.5 times the head from a single pump...

It is more like 90% + in reality, theoretically its 100% more head.

[Graystar]

running pumps in series is great for larger multi-block or restrictive systems
Right. Because you get more flow. What good is more pressure if you don't get more flow??

In PC water-cooling, the only reasons for two pumps in series are redundancy and increased flow. No one has ever added a second pump for the sole purpose of increasing pressure, and not caring about increased flow. "More consistent flowrate"?? What's that?? That's meaningless!

Unbelievable...with all the discussions, all the testing, I just have no idea where people are pulling this stuff from.

[ramenchef]

You get more flow because there is more head pressure. Higher head pressure means it can sustain more restrictiveness with less drop in flowrate.