W.C. loop length, affect performance?

[paulc]

W.C. case choice

After much thinking I've pretty much settled on a Mountain Mods U2-UFO as my ideal w/c case - no modding needed, everything will fit out of the box. Fairly expensive and rather large, but its the sort of case that will keep going for a good few years. Only possible draw-back I can think of is, depending on how the loop is installed, the loop length might be slightly longer than in a tower case. Any thoughts from anyone else?

 

[MikeTimbers]

The longer the loop, the greater the friction so the lower the flow. But it's unlikely that the loop will be so much longer as to make a huge difference.

 

[sablabra]

Tube length doesn't really make any difference, imo(relative...)

 

[w3bbo]

Dosn't make that much difference but it DOES make a difference

 

[smids]

Tube length is fairly important, but so long as you get a good enough pump, losing a bit of head and flow won't affect the performance too much. I really recommend the 18W (red impeller) Laing DDC with Alphacool modded Pro top (using the top inlet). This gives about 6.6m of head height - compare that to most other pumps e.g. D5 of about 3.7m, you see how good that tiny pump is. The heatump is also a lot less at about 15W compared to the 24W of a D5.

 

[sablabra]

Naah, it's not important IMO. I know a bunch of guys having the radiator in the basement or outside, which means what, 15ft of tubing? That works excellent, even with a weak EHEIM pump. What ever you say, it doesn't really mather

 

[smids]

Naah, it's not important IMO. I know a bunch of guys having the radiator in the basement or outside, which means what, 15ft of tubing? That works excellent, even with a weak EHEIM pump. What ever you say, it doesn't really mather

Eheims are high flow pumps - so long as the loop isn't super restrictive, the pump can handle it. Think about pond/tank situations - a lot of these have long tubes....

Anyway, on XS, all of the WC testers impress on the importance of it, so I'm not going to disagree with them. I have a very restrictive loop so every bit of resistance is important to me.

 

[DaveMac]

After much thinking I've pretty much settled on a Mountain Mods U2-UFO as my ideal w/c case - no modding needed, everything will fit out of the box. Fairly expensive and rather large, but its the sort of case that will keep going for a good few years. Only possible draw-back I can think of is, depending on how the loop is installed, the loop length might be slightly longer than in a tower case. Any thoughts from anyone else?

More food for thought: it could actually perform better as the MM cases have the rads vertically mounted the pump isn't lifting as high as say a top mounted rad in a full tower case, and the components can be closer together in the cube shape rather than drawn out in an extended narrow rectangle.

 

[pastymuncher]

I have my rad mounted on the windowsill outside my pc room and have around 20 feet of 7/16" tubing and 2x6 foot lengths of 15mm copper tubing as well and i am getting excellent temps. 20 idle/28 load for the cpu and 31 idle/35 load for the gpu's. I don't think the new Nvidia CP can read below 31 though as it's on that at start up. I have a Aquaextreme 50z pump which is one of the best for head height and it also dumps the less heat.

 

[smids]

I have my rad mounted on the windowsill outside my pc room and have around 20 feet of 7/16" tubing and 2x6 foot lengths of 15mm copper tubing as well and i am getting excellent temps. 20 idle/28 load for the cpu and 31 idle/35 load for the gpu's. I don't think the new Nvidia CP can read below 31 though as it's on that at start up. I have a Aquaextreme 50z pump which is one of the best for head height and it also dumps the less heat.

That's on a windowsill... I'm not the one stating this whole thing about length - it's the experts - and they have conducted tests. The 50z is a good pump though, and can handle that. However, you might get better performance with a shorter loop . Also, as I infered in my post, it depends heavily on the components used. If you use low flow components such as an Apogee or Swifffy 6002, then you aren't going to be affected as much.

 

[Its_Me]

rad hieght is not important as the mavity on the downward return effectively equals it out. Think of it as a syphon tube attached to the pump.

Our suystems have an effective zero head as such, but do have flow restriction.

Obviuosly its all relative to the pipe diameter too, so you can get away with a slightly longer system in 1/2".
Its important to remember though that a tight radius is more restrictive then the use of extra length of pipe to smooth the radius out, and avoid elbows if at all possible.

 

[ace1981]

if tube lengh doesnt matter that must mean i could use about 6 meters each way, just a thought move the rad and alloy xspc passive resovoir near the window and air con?

that must work?

or lol put the rad in my can chiller fridge that will work just joking

 

[pastymuncher]

Thats almost exactly how mine is set up apart from my XSPC res is in my pc room. Having the rad on the windowsill with the window open was an excellent move for me and it's only going to get better as the winter approaches. Not to sure about leaving the window open all the time then though.

Just to let you know, the rest of my components are:-
Aquaextreme 50z pump,
Aquaextreme MP-05 Pro limited edition cpu block,
Aquaextreme MP-1 x2 gpu blocks,
XSPC 250mm passive reservoir,
Alphacool Xtreme lll triple rad,
20 feet 7/16" Masterkleer tubing,
2x 6 foot lengths of 15mm copper pipe,
4x 15mm to 8mm stepdowns for each end of the copper pipe (drilled out from 8 to 12mm though).
3x Akasa Amber 120mm fans (will change for summer operation.
Home made shroud for the fans/radiator.
Home made sound insulated box for the res to mount on and also contains the pump and the 200w switchable powersupply that powers the whole watercooling setup independantly from the pc. This was a good move too as i can switch it on before the pc to pre-cool the water and also leave it on after to keep removing heat from the pc after it is shut off.

 

[MikeTimbers]

Tube length does matter! It's only that the amount it matters is determined by other factors.

Assume for a moment that the restriction of 1 meter of tubing = -0.2LPM which is a reasonable figure (go look on Proc-Cooling if you disagree)

If your pump throught the blocks (ignoring the tubing) is able to produce 2LPM, then a normal size loop of around 1-2M is a restriction of 0.2-0.4 LPM which is only between 10% and 20%. Not too bad.

Now suppose your loop is 5M. The restriction is -1LPM and that reduces your flow by 50%! That's huge.

What if you have a massive pump generating 10LPM. Your normal loop is now only 2-4% and your 5M loop is still only 10%.

The amount that tubing length matters is dependent upon your pump's ability to push through it. The bigger the pump, the less the tubing length matters. The smaller the pump, the more the length matters.

NB. Please remember that your pump's publicised flow-rate is free-flow and does not represent what will be achieved through your blocks, tubing, res and rads.