Liquid Cooling Flow

pharoahdawson

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Feb 2, 2014
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I want to cool my cpu (i7 4770K), motherboard (Gigabyte GA Z87X OC Force), and a single video card (to be determined later). Can I run the output from the reservoir to a (one) radiator splitting the output three ways sending them to the separate components and rejoining those outputs (by a splitter in reverse) before sending the flow back out to the (one) reservoir. Or; Should I split the flow directly from the reservoir 3 ways running them out through 3 separate radiators and on to the separate components and then rejoin the lines on their way back to the (one)reservoir? Shortened could I use one radiator or do I need three? How much does splitting the lines via splitters effect the overall coolant flow and performance? I know its a long question but sometimes its the little details that make the biggest differences. I should add that I am new to liquid cooling but I learn fast and have a lot of common (not so common anymore LOL) sense.
 
Solution
like i said, one 120mm radiator per component. a single 280mm rad would not be sufficient for 3 components and would even be advised against for cooling two components on its own
You need to run the output from the reservoir directly to the pump, and from there it is suggested to go in sequence rather than splitting. so you then go from the pump to your cpu, and then to either your gpu, or back to your radiator, and then to your gpu with it eventually going back into the reservoir (really doesnt matter as long as you have 1 single line of flow. Do not split lines in water cooling. The water in your tubing before and after your graphics card rarely differs by even 3 degrees.
 
All you would do to add another radiator if you so chose too would be to disconnect at any point and make that connection run to the additional radiator instead of going straight to the next part, and then have the output from that new radiator going to the next point in the system.

splitting lines just reduces the equality of water pressure going through each part, and you may get uneven cooling throughout your system
 

pharoahdawson

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Feb 2, 2014
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So I should run:
Reservoir to radiator to component to radiator2 to component2 to radiator3 to component3 and then back to the reservoir thus creating 1 big loop. Am I understanding this correctly? Does this kind of setup require a higher powered pump to insure proper flow?
 
You CAN do it that way, but you will get the same temps as
Reservoir to pump*** (this is important and start with this always having reservoir above pump, as running your pump dry can and will kill it). then pump to component 1 to component 2 to component 3 to radiator 1 to radiator 2 to radiator 3. Basically do whatever gives you the most preferable look of your tubing.

most people try for a cleaner look, and so a good method is to try not to have tubing crossed over each other
 
a good method that is pretty common is
reservoir to pump to radiator 1 to cpu to gpu1 through 4 to radiator 2 and then back to reservoir. this is probably the cleanest way to set it up, but obviously it is your own loop and you can choose to do it however you want
 

pharoahdawson

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Feb 2, 2014
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I say reservoir because the system I am looking at has the pump inside the reservoir and connections are made directly to the reservoir (XSPC Dual 5.25" Bay Black Reservoir - w/ D5 Variant Pump Installed). Question: If I send the flow directly from component1 to component2 and so on am I not just sending the heat of one component to the next? Would it not be more advantageous to send the flow back to a radiator for cooling before moving on to the next component? If not why? Sorry to pester you but I'm learning here. I'd rather ask the questions here before messing up my build.
 
No problem, and sending flow from component 1 to component 2 doesnt really affect temps because the fluid in the system is more of a constant throughout rather than getting super hot after going from one component. the temp difference between water right before going into a cpu under load might be 56 degrees while the water coming out of that component might be 57-58 degrees. a rather non important temp variance.
 
so sending the flow back to a radiator after a component will be slightly better for temps, but if it is going to make your system look like Frankenstein's intestines, then it is not worth it to do so and will require a stronger pump due (not like leaps and bounds stronger, but just slightly stronger) to the increased amount of tubing and changes in direction to the flow
 

pharoahdawson

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Feb 2, 2014
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Space really isn't a big issue. I'm using the Cooler Master Cosmos II case (plenty of room for a top 360mm radiator, Rear 140mm Radiator, and bottom mounted 240mm radiator) but if I can save money by eliminating the need for 3 radiators I'm game.
Question: So then could I Run
Reservoir/Pump to radiator to component1 to component2 to component3 and then back to the reservoir without my temps jumping crazy. Shortened: Could I get by with using say 1 280mm radiator in a push pull configuration? Shouldn't this also cut down on the amount of tubes running through the case?
 
yes of course you could do that, but remember then, you would be cooling both your cpu and gpu with just that 1 280mm rad. my personal recommendation would be to have that first rad at the top, and then maybe the extra 140mm rad on the back

basically best idea is to have the biggest rad on the bottom as an intake (fans pulling or pushing (or both) air from below through the radiator and into case, then say adding a radiator to either the front of the case as an intake or the back, and having the top be purely for exhaust rather than going through another radiator
 
Feb 17, 2019
14
0
10
I'm new to this. Just looking at this thread, researching for my first go. I'm studying plumbing at college. From a plumbing perspective, some things just don't make sense to me, like the lack of manual or auto air admittance valve for priming. I'm very tempted to use compression fittings going to 10mm microbore copper tubing, and soldered joints. It's easy to get perfect bends with a handheld bender. It might look a bit industrial like a Mamod engine. I'm tempted to have a separate flow and return run too. Without the circulator, the liquid will naturally want the rise up. Once cooled, it will fall back down. It makes sense to me, not to go against the grain. In other words, let the pump help the coolant to flow the way it wants to naturally. Where the pump is seems fairly irrelevant, as it is a closed system. Otherwise the reservoir would need to be higher than the top rad. The only concern about placement would whether the pump could handle the heat, straight from the chips. I shouldn't imagine that's a problem. Back to the pipe layout. Surely you want both blocks to receive roughly equal qualities of cool water, not for one to get pre heated water? Wouldn't a separate flow and return
I want to cool my cpu (i7 4770K), motherboard (Gigabyte GA Z87X OC Force), and a single video card (to be determined later). Can I run the output from the reservoir to a (one) radiator splitting the output three ways sending them to the separate components and rejoining those outputs (by a splitter in reverse) before sending the flow back out to the (one) reservoir. Or; Should I split the flow directly from the reservoir 3 ways running them out through 3 separate radiators and on to the separate components and then rejoin the lines on their way back to the (one)reservoir? Shortened could I use one radiator or do I need three? How much does splitting the lines via splitters effect the overall coolant flow and performance? I know its a long question but sometimes its the little details that make the biggest differences. I should add that I am new to liquid cooling but I learn fast and have a lot of common (not so common anymore LOL) sense.

I'm looking into liquid cooling for the first time. I'm studying plumbing in college. The principles are the same. It's small scale plumbing, basically. Yet people seem to have the funniest ideas. I intend to experiment for my first go. I'm going to try connecting 10mm microbore copper tubes, using compression fittings, soldered joints, fittings, and jointing compound. Should be no leaks. I'm with you. Ideally, both water blocks, would both receive water at the same temperature. If the water going around is all the same temperature, then the pump speed is wrong. I'm going to try separate flow and return pipework, like you have in central heating. There should be a fall in temperature, between the flow and return. This indicates how much heat the radiators are dissipating. The drawback to this method is that there are no valves and, hence, no way to balance anything. On the up side, I would have thought it would be easier on the pump; like trying to breath through a straw, vs trying to breath through 2 straws.
 

rubix_1011

Contributing Writer
Moderator
A lot of confusing information in this thread, but some is good.

Flow direction or order does not make any difference in temperatures. Just ensure that the pump cannot draw in air, either from the reservoir or elsewhere.

Splitting flow is a means of parallel of flow; many people do this for more restrictive blocks like GPUs, but isn't needed for high-flow components like radiators where restriction is usually much lower.

Coolant temps should be fairly equal at any single point in the loop - if you were to register temps at several points in the flow order, they would likely be relatively similar. Coolant tends to equalize as a whole unit and not have localized 'hot spots' unless you have an area of restricted flow among areas of otherwise uninterrupted flow (poor parallel segment, for example).

Serial flow (one component to the next in order) is how most people, including myself, tend to setup their loops, although I have run dual GPUs with parallel flow, which helps...the flow is split into each GPU inlet and reconvenes at the GPU outlet. Serial tends to be more restrictive overall in a single segment vs. the same segment where there are parallel runs. I'm not a fluid dynamics engineer, so much of the technical explanation needs to be done by someone more knowledgeable than I, so here you go: https://www.overclock.net/forum/61-water-cooling/1557844-serial-vs-parallel.html

This has been discussed many, many times over and it really comes down to preference and flow rate. Personally, I will always parallel dual GPU blocks, although I've considered running parallel my CPU block and GPU block just to see what happens.
 
Feb 17, 2019
14
0
10
I would expect the temp to become nearly equalised eventually. The difference between the flow and return, is the amount that has been shed. If flow and return are the same, surely that indicates either a) hardly any heat has been lost (rads too small or not enough? b) heated water is returning to the blocks, before it has had time to be cooled by the rads (pump too fast?). The water only needs to go slowly through a rad for it to work. Some kind of circulator is more efficient, and helps the water around. However, heated water is capable of rising and falling without a circulator. It thermosyphons, due to a density difference between the hot water in the flow and the cold water in the return. The trouble is, it tends be better at expelling heat through the highest rads. Giving it a helping hand, helps all rads heat up the same. By the time the time water is coming out of a rad, it should be noticeably cooler than when it went in. Otherwise the rad hasn't done anything, and you're sending hot water back out of it. I feel like maybe I'm missing an important point here.