Silly question about more than 2 DDC pumps in series

[tgm_of_xxl]

Hi folks,

I have the opportunity to link more than 2 DDC 18W pumps in series in a single loop.
My loop consists of an external radiator build out of 3x360mm UT60 Alphacool rads, 1 EK Supreme HF block JP#6, 1xEK X58 Mosfet+Chipset blocks, 1xEK Dominatorx6 RAM WB, 2xEK 580GTX FC WB and 1xAquaero 5XT WB in series. As a reservoir/pump combo I am planning to use Alphacool Repack Quad Laing DDC http://www.alphacool.com/product_inf...y-Station.html
I do not know how much of a flow I have right now as the sistem is not yet fully assembled.
Do you think 4 pumps will help improve temperatures/flow over 2 pumps. I also consider running them at less than 12V for added silence. Maybe something like 9-10V.

What do you think?

Regards, TGM.

[musicfan]

Hi folks,

I have the opportunity to link more than 2 DDC 18W pumps in series in a single loop.
My loop consists of an external radiator build out of 3x360mm UT60 Alphacool rads, 1 EK Supreme HF block JP#6, 1xEK X58 Mosfet+Chipset blocks, 1xEK Dominatorx6 RAM WB, 2xEK 580GTX FC WB and 1xAquaero 5XT WB in series. As a reservoir/pump combo I am planning to use Alphacool Repack Quad Laing DDC http://www.alphacool.com/product_inf...y-Station.html
I do not know how much of a flow I have right now as the sistem is not yet fully assembled.
Do you think 4 pumps will help improve temperatures/flow over 2 pumps. I also consider running them at less than 12V for added silence. Maybe something like 9-10V.

What do you think?

Regards, TGM.

The below is from Martinm210 at http://martinsliquidlab.org/pump-and...r-spreadsheet/ under "How Much Flow Rate is Enough?"

The differences are generally less than a degree past about 1 gallon per minute. I personally have run loops down to about .9 GPM in single block loops, but the general rule of thumb is to keep flow rates above 1 GPM if possible and you can see a few fractions of a degree gain beyond that “IF” you don’t add too much pump heat. Eventually as you get to the 40-50 watts worth of pumping power, the pump heat itself starts to cause more harm than the good you are getting with flow rate.

As I understand, you want flow about 1 to 1.5 gpm. I use two pumps in series so I can appreciate wanting one for pump redundancy but two healthy DDC 18W pumps in series should be more than adequate in one loop, even a restrictive or big one. IMO, I don't see the value in using four DDC 18 W in series for the single loop you describe. Martinm210 has an Excel spreadsheet at the same link. You can substitute different components with similar restriction and get an approximation of flow. Good luck.

[eth0s]

Hmm, I dunno. Four pumps at 12V is overkill. You won't get any better temps with four pumps than with two pumps. However, using four pumps at 9V sounds like an interesting idea. I say try it and see what happens. Try to put a flow meter in the loop to see what happens with flow. Also, I can tell you from my own experimentation that four DDC pumps in series at 12V will give 4 times the head pressure which will cause some weird things to happen. Your tubes will bulge out from the pressure, and you may see a leak spring from one of your fancy articulated fittings, so be careful with that. Also you may get some cavitation if your loop has extremely low restriction. But on the plus side, your flow rate will be phenomenal.

[tgm_of_xxl]

I was planning of throttling them down by using Aquaero 5XT along with 3 additional PowerAdjust 2 Ultras (one pump on the AQ5XT and 3 on the PA2U) to something like 9-10V mainly because of noise and heat dump. The system is not very low restriction mainly because of the many blocks and long tubing (as mentioned before the rads are outside the case). From a fitting perspective I've tried to stick with straight compression fittings. Exceptions: Koolance QD for the computer case and rads stand and some 90 deg compression fittings for linking the rads.

Guys, your feedback is greatly appreciated!

TGM.

[tgm_of_xxl]

Because the water block on the Aquaero 5XT has the most of restriction I have decided to make 2 parallel loops:
- main loop with all the system and the rads with 2 DDC3.25 pumps in series;
- secondary loop with only the water block on the Aquaero 5XT and with a DDC 10W pump only;
Based on performance (temps & flow) I might decide to go to initial design with 4 DDC 3.25 in series, throttled down with Aquaero 5XT & 3xPowerAdjust 2 Ultra.