So I added a second pump..

[Idef1x]

I recently got a second 18 watts DDC (355) for my birthday, so I bought the "Aquacover Dual DDC" and the EK Spin reservoir which replaced my XSPC Dual Bay reservoir which had a single DDC.

Believe it or not, I am getting slightly worse temperatures now. I'm thinking it might be because the second pump is heating the water a tiny bit, or it might be that bloody reservoir not bleeding properly, but I had hoped for a least 1-3 degrees celsius better performance.

As far as I understand, the higher pressure head ought to give a higher flow. Do you guys have any thoughts on this?

EDIT: Or perhaps I just have so much flow, that the radiators are the bottle neck?

 

[FaRKle0079]

You sure about your temp increase and it's not just due to ambient fluctuations? Also, if your loop wasn't flow-starved before you shouldn't really see any tangible changes.

 

[Idef1x]

You sure about your temp increase and it's not just due to ambient fluctuations? Also, if your loop wasn't flow-starved before you shouldn't really see any tangible changes.

After further inspection, it might not give higher temperatures, but it doesn't help either. A bit of a letdown, but guess I'm bottlenecked somewhere else in the system.

 

[86 5.0L]

Why would you think a second pump would help?

 

[MetaKnight]

Why would you think a second pump would help?

A reasoning would be that if the liquid is being speeded up adding a second pump then it is less likely to have an increase in temperature if the flow was sluggish in certain areas or just not fast enough overall. I asked a friend about this years ago and he said unfortunately that it's not helpful.

Believe it or not, I am getting slightly worse temperatures now.

As far as I understand, the higher pressure head ought to give a higher flow. Do you guys have any thoughts on this?

EDIT: Or perhaps I just have so much flow, that the radiators are the bottle neck?

Increase in temps? FaRKle said it.

You sure about your temp increase and it's not just due to ambient fluctuations? Also, if your loop wasn't flow-starved before you shouldn't really see any tangible changes.

Pretty much this is what my friend told me and if this wrong then somebody please correct me here. If you have one pump and install a second the priority flow will render the weaker pump all but useless. If they are both the same pump (same speed) then the flow isn't going to increase because they are moving the liquid together at the same speed thus nothing has changed. Eitherway it's pointless.

Note: I was going to suggest push/pull, but then read your last topics as I was finishing the reply.

A simple question to all you water guys -

Will three 3000 RPM Gentle Typhoons be sufficient to pull air through the HW Labs Black ICE GTX, which I understand is a quite dense radiator?

Sorry if the answer is obvious - I am a total water newb.

EDIT: I am aware, that the fans have a relatively high pressure and cfm - the point is, there will be only three of them pulling, since I don't have room for push/pull.
EDIT2: By looking at Skinneelabs review of the radiator, I figure, that I will be fine with only three fans pulling.

The CPU ranges from 33-37 idle, and 58-62 during full load (Used to do 72 on quite aggressive air, but It ran quite low compared to others in my experience). But the (quite unexpected) ace of the rig is the graphics cards temperatures. They idle at respectively 28 & 34. During Crisis with everything on "Very High" at 2550/1440, it tops at 43. Other games wont even get it to 40! And that is with 840/1325 overclock, which is the highest allowed by the CCC.

And also saw your setup. Good job. Your temps seem good to me.

 

[Idef1x]

Why would you think a second pump would help?

Pretty much this is what my friend told me and if this wrong then somebody please correct me here. If you have one pump and install a second the priority flow will render the weaker pump all but useless. If they are both the same pump (same speed) then the flow isn't going to increase because they are moving the liquid together at the same speed thus nothing has changed. Eitherway it's pointless.

No it isn't pointless. When you add a second pump in series, you practically double the pressure head, and by that you also increase the flow.If your loop (theoretically) had no restriction, both a single and two pumps would do 600 lph, but since your water blocks and radiators add restriction, they won't do 600 lph. At a given restriction, one pump might be able to push ie. 340 lph, where two pumps in series will be able to push closer to the max. And ofc you use two similar pumps, or you will damage both of them.

Take a look at these charts from Skinnee, showing the increase in pressure.

http://skinneelabs.com/ddc_ac-dual/

 

[86 5.0L]

Ok, but it's a balance, more flow =\= lower temps. A slower flow of water will let it be in the blocks longer absorbing more heat, subsequently it will be in a rad longer, dumping that heat. Aslong as your flow stays above the golden rule of 1 Gallon Per Minute. Temps will stay nearly linear.

 

[Aus10]

Off topic but that is a really good looking build very clean i like it a lot..

 

[MetaKnight]

No it isn't pointless. When you add a second pump in series, you practically double the pressure head, and by that you also increase the flow.If your loop (theoretically) had no restriction, both a single and two pumps would do 600 lph, but since your water blocks and radiators add restriction, they won't do 600 lph. At a given restriction, one pump might be able to push ie. 340 lph, where two pumps in series will be able to push closer to the max. And ofc you use two similar pumps, or you will damage both of them.

Take a look at these charts from Skinnee, showing the increase in pressure.

http://skinneelabs.com/ddc_ac-dual/

Ahh, thanks for that. I look forward to talking to my friend and showing him those charts, but nonetheless I don't see any temps from the charts there and that's really the main point of what I was trying to make (despite being incorrect about the flow) is that after contemplating normal flow (one pump) vs. increased flow (two pumps or more) I wouldn't imagine much, if any, lower temps arise from this because I came to something of the same conclusion as this

VVVV​

Ok, but it's a balance, more flow =\= lower temps. A slower flow of water will let it be in the blocks longer absorbing more heat, subsequently it will be in a rad longer, dumping that heat. Aslong as your flow stays above the golden rule of 1 Gallon Per Minute. Temps will stay nearly linear.

 

[DenverBarr]

it wont help alot but it shouldn't increase

 

[TheMadHatterXxX]

Where's all the wires in that pic?

 

[MrBean_Oz]

The benefit of a second pump in most pc watercooling applications is for redundancy, not flow.

There would be very low observable benefits wrt temperature if your flow was above 4lpm to begin with.

Don't worry about it, just keep the 2nd pump running for the added safety benefit - it's a good thing

 

[DeathPrincess]

Yes, a second pump is good as a failsafe. You can even leave the loop running with a broken pump.

Where's all the wires in that pic?

Normally people place them behind the motherboard, but in this case, its one of those modern new fangled wireless computers!