Series or parallel?

[baja150]

I've got a question about how to route my tubing in my small bore (6mm ID/8mm OD) water cooling system.

I've seen a few other small bore systems that have everything ran in series, but they are all using something like the Eheim 1046 or 1048 pumps which are

1046 = 79GPH w/ 3'11" delivery head (1/2" input - 3/8" output)
1048 = 158GPH w/ 4'11" delivery head (1/2" input - 3/8" output)

I'll be using the Eheim 1260 which is 602GPH w/ 10'2" delivery head (1" input - 3/4" output)

I'll be pumping through the radiator and 4 water blocks (CPU, GPU, Chipset, and HDD). Because of the output of the pump I'm thinking it may be better to run all 4 blocks in parallel. I would run 1/2" ID tubing and split off four 1/4" ID tubes from that to go to each block. My only fear is that if the resistance to flow is not equal in all the blocks then some of them may be neglected adequate flow.

What do you guys think? Your opinions are very valuable to me.

Thanks!

 

[Sideroxylon]

Your right. Water will follow the path of least resistance, so you may not get adequate flow throughout the loops. If you could find some kind of manifold that would keep flow constant to all loops that would be your answer.

Why don't you want to run them in series?

 

[Steel Chicken]

series is mucho better
the actual temp increase in the water right after a heating element is very small

 

[Erasmus354]

yep, run them in series. Although most blocks designed for such small diameter tubing dont scale very much with increased flow (they usually perform close to their max under even low flow circumstances) so you might do just fine with parallel as well.

If you can however, use a resevoir, and have the connection from the resevoir to the pump inlet be as large a diameter as possible (it would be best if you could match the size of the pumps inlet). Pumps perform best when they have an unrestricted inlet, having the outlet restricted is not as big a problem as having a restricted inlet.

The best example I can give of the restricted inlet problem is the Laing DDC. If you look at the inlet you notice it makes a right angle turn (follow the pump housing to the middle). The modification done to the DDC(there is a link to it on the forums here uncer a post called mcp350 mod or something) takes out that restrictive bend, and it increases the flow of the pump by 70%. Moral of the story...dont choke off your pumps inlet, make it as unrestricted as possible.

 

[baja150]

Thanks for the replies guys.

Erasmus - In reference to the pump inlet. I'm using a 5 gallon fish aquarium for a reservoir. If it's doesn't cost too much I'm going to have the glass cut and have a 1" bulkhead through the tank so I can run a 1" hose to the pump inlet. If it's too expensive to have the glass cut I'll just submerse the pump inside the tank. Either way the pump will have enough supply.

Here's my proposed idea:

I scrapped the HDD cooler.

Run 1/2"ID tubing from the pump upto a manifold that splits off into three 1/4"ID tubes. One for each waterblock in parallel (CPU, GPU, and Chipset). Then exit the waterblocks and run each individual 1/4"ID tube back to the reservoir each with it's own flow meter and adjustable valve; 3 flow meters and 3 valves. This way I could equalize the flow between each of the 3 circuits.

Well? What do you think?

 

[Top Nurse]

Are you running an Aqua-Computer or Koolance set of coolers? If so which ones? Choice depends on specific coolers as there are differences in flow resistance. I'm building a similar setup where I'm using an Eheim 1046 fed from a dual 5.25" reservoir through 3/8" tubing. From the pump to the radiator is 3/8" as well. From the radiator outlet I go via another 3/8" line into a custom made coolant header which splits into three separate 1/4" lines. So in effect I have three separate 1/4" lines going back to the reservoir. My circuits are as follows:

Header => CPU => NB => Reservoir
Header => GPU 1 => GPU2 => Reservoir
Header => HDD1 => HDD2 => HDD3 => Reservoir

You can see some of this at my website.

When my Aqua-Computer gear gets here I will be using the Aquaero for flow and temp measurement as well as fan control. The AquaStream pump will also be attached in lieu of the 1046. And I will in all probability add a dual 240 AirPlex EVO to the fray as well.

 

[baja150]

Top Nurse - Wow I looked at your website and our systems are pretty similar. I have the same 3 Koolance blocks you have on the same Asus MB. Well actually mine are on order and may be here later today. I hope the chipset cooler fits with my 6800 Ultra, my card is quite a bit larger than yours... it goes all the way to the end of the mobo.

You may be interested in this splitter. It's 1/2"OD input and three 3/8"OD outputs.

I was also looking at the AirPlex EVO's, but the only place in the US I knew to order them from was SNT Systems and they're all out of stock. I bought a HWLabs BIXIII (Triple 120mm) instead.

I also am planning on using the Aquaero or maybe the Fan-O-Matic.

I posted a similar thread to this one over at xtremesystems.org and someone over there higly recommended against running anything in parallel, but I think I'm going to try it anyways. I'm no fluid dynamics genius, but I'm pretty good when it comes to technical things like this and I just can't see any negatives to splitting off one larger size tube to several smaller size tubes in parallel. I do think it is important to have a way to regulate your flow to equalize flow between all the different circuits.

I'm going to have my radiator, reservoir, and pump set up in my basement direcly below my office. Should work out nice since it's always about 10°F cooler down there. Plus I can run some super high RPM fans on the radiator if it helps and not have to worry about noise. I was lucky that my mechanical room was directly below my office.

Did you add another pump yet? I think you'll be asking a bit much of a 1046 to pump through seven 1/4"waterblocks. Also, most places I've read recommend a 120mm x 3 radiator for systems cooling a CPU and two GPU's.

Let me know how things work out for you once your up and running.

 

[Top Nurse]

You may be interested in this splitter. It's 1/2"OD input and three 3/8"OD outputs.

I had seen that one before but it was just too long and the Pound to the Dollar rates suck big time

I was also looking at the AirPlex EVO's...I bought a HWLabs BIXIII (Triple 120mm) instead.

I think that the AirPlex Evo's may be over rated, but will know better in a week or so. But their grills are outstanding! Considering a price performance ratio you probably made the better choice.

I also am planning on using the Aquaero or maybe the Fan-O-Matic.

After looking in to this for quite a while I think the Aquaero is the better deal. See this thread for more info. The Aquaero has a new software suite that should be available by early next week and it has a lot more capabilities than the Innovatek Fan-O-Matic.

I posted a similar thread to this one over at xtremesystems.org and someone over there higly recommended against running anything in parallel.

Well I suppose that some find it unappealing but if designed right it should not present any problems.

Did you add another pump yet? I think you'll be asking a bit much of a 1046 to pump through seven 1/4"waterblocks. Also, most places I've read recommend a 120mm x 3 radiator for systems cooling a CPU and two GPU's.

Ahh bullshit....I mean like my Koolance EXOS I with its little 1 liter/min pump cooling a 2400+ OC to 2.4Ghz + NB + ATi 9800 Pro AND NO PROBLEMS.... I saw a dual Xeon running with TEC's and it only needed two 120mm HW Labs radiators and an Eheim 1046 pump. So much for self-styled Guru's that keep regurgitating what they read the day before