Y spliting water flow in custom loop

[KJaboski]

Hey all watercooling gurus.

 

I'm playing with the idea of doing some changes with my custom loop for the summer and was wondering about an idea.

 

Has anyone seen or heard or had experience with spliting water flow with a Y piece or similar? I wonder if I could pull of spliting the out of the pump into two flows one going into GPU,CPU and maybe one rad, then back to the res/pump combo. The other to one or maybe two rads and then back to res/pump combo.

 

In my head this would be to just achieve some clean looks with tubing and maybe having the CPU + GPU done with hard tubing whiles rest could be done with soft tubing hidden out of sight.

I'm not so sure about the implications to performance this might have due to reduced flow rate by half etc...

 

Thanks guys.

KJ

[LogicalDrm]

-> Moved to Custom Loop and Exotic Cooling

[MaratM]

you are talking about parallel flow. Yes it works many people done it and it works without any problems. I have one on of my rigs. the link to it it is in the signature. 
the flow path is res->pump->GPU+CPU->rad and back to the res. did not have any problems with it except it is a bit tricky to bleed all the air out ance it is done it runs without any problems.

[bowrilla]

I have such a loop. CPU + GPU are in parallel and both radiators are in parallel. You need to be aware, that by splitting up the flow you ideally get half the flow through both routes. However, differences in restriction will divide the flow asymmetrically (relative to the restriction ratio). It is also a cost factor since you need more fittings to get everything connected. Also: make sure to use actual Y splitter and not just a straight fitting with a 30° or 45° junction because that will not divide the flow symmetrically, there'll be a lot more flow going straight down the run.

 

Next point: make sure you align everything properly. It can look very pretty indeed but everything needs to line up perfectly. I have a top and bottom radiator and the case was not designed for them to be perfectly aligned, the bottom one is now moved over to the 120mm mounting holes and one side is not mounted at all. Biggest trick though is aligning GPU and CPU blocks in a way that you'll get a nice looking run. You might need to turn your CPU block away from the optimal orientation (with Ryzen this has an impact). 

 

Bleeding such a system can also be even more tricky and let me tell you: you will most likely underestimate how much space you actually need for all those runs and turns and extra fittings. My Corsair 280X is pretty full and I've put the pump in the back cmpartment next to the PSU - removed an additional drive cage. Oh and mounting everything is really tricky as well. At first I intended to use 45° rotaries on the Y-fittings to get a straight line but then I realized that I couldn't actually mount the tubes and the Y-adaptor in between a top and bottom radiator. So I had to do some 45° bends with virtually no wiggle room and no room for errors. 4 runs that needed to be exactly (!) the same. There was still some painful (to me) pushing and bending involved to mount it.

 

I can post pictures if you like, but first I need to flush it and fill it with the actual inteded fluid (right now there's just distilled water in it, I only finished it the week before christmas).

 

tl;dr totally possible, but more complicated. Make very sure the case and your components align well.

[KJaboski]

On 1/17/2021 at 5:24 PM, MaratM said:

you are talking about parallel flow. Yes it works many people done it and it works without any problems. I have one on of my rigs. the link to it it is in the signature. 
the flow path is res->pump->GPU+CPU->rad and back to the res. did not have any problems with it except it is a bit tricky to bleed all the air out ance it is done it runs without any problems.

 

On 1/17/2021 at 9:44 PM, bowrilla said:

I have such a loop. CPU + GPU are in parallel and both radiators are in parallel. You need to be aware, that by splitting up the flow you ideally get half the flow through both routes. However, differences in restriction will divide the flow asymmetrically (relative to the restriction ratio). It is also a cost factor since you need more fittings to get everything connected. Also: make sure to use actual Y splitter and not just a straight fitting with a 30° or 45° junction because that will not divide the flow symmetrically, there'll be a lot more flow going straight down the run.

 

Next point: make sure you align everything properly. It can look very pretty indeed but everything needs to line up perfectly. I have a top and bottom radiator and the case was not designed for them to be perfectly aligned, the bottom one is now moved over to the 120mm mounting holes and one side is not mounted at all. Biggest trick though is aligning GPU and CPU blocks in a way that you'll get a nice looking run. You might need to turn your CPU block away from the optimal orientation (with Ryzen this has an impact). 

 

Bleeding such a system can also be even more tricky and let me tell you: you will most likely underestimate how much space you actually need for all those runs and turns and extra fittings. My Corsair 280X is pretty full and I've put the pump in the back cmpartment next to the PSU - removed an additional drive cage. Oh and mounting everything is really tricky as well. At first I intended to use 45° rotaries on the Y-fittings to get a straight line but then I realized that I couldn't actually mount the tubes and the Y-adaptor in between a top and bottom radiator. So I had to do some 45° bends with virtually no wiggle room and no room for errors. 4 runs that needed to be exactly (!) the same. There was still some painful (to me) pushing and bending involved to mount it.

 

I can post pictures if you like, but first I need to flush it and fill it with the actual inteded fluid (right now there's just distilled water in it, I only finished it the week before christmas).

 

tl;dr totally possible, but more complicated. Make very sure the case and your components align well.

Thanks for your replies. I'll look into my options and consider whats possible.

 

I'm not 100% sold on hard line as yes space in my H440 might be limited. Changing the case is probably too much to think of right now.

 

I also had a mad and expensive idea of using two pumps one for each flow path but fed out of the same res ;D overkill... I know but a way to eliminate flow reduction after the split.

[bowrilla]

25 minutes ago, KJaboski said:

 

Thanks for your replies. I'll look into my options and consider whats possible.

 

I'm not 100% sold on hard line as yes space in my H440 might be limited. Changing the case is probably too much to think of right now.

 

I also had a mad and expensive idea of using two pumps one for each flow path but fed out of the same res ;D overkill... I know but a way to eliminate flow reduction after the split.

In that case I'd just go for dual loop. Add another (pump) res and you have dual loops, everything separated and you can go with two different fluids.

 

But seriously: people fuss too much about flow. What I was trying to say is: make sure both blocks are similar in terms of flow restriction. As long as you have measruable flow, the loop works. Yes, very little flow will increase temps by a few (most likely single digit) K but unless you're trying to hit record OC this will not be of any noticeable effect. To my knowledge the EK blocks (GPU and CPU) are very similar in terms of restriction (but please, google some measurements, there are more in depth tests of all the major blocks, with the GPU ones the specific sub versions do not matter) so you'll be around 50:50 split. Stick to the same radiators and you will have a 50:50 split as well. The minor points of one more bend will not make a huge difference - probably only measurable with very professional equipment (all the flow sensors with the exception of the aquacomputer ones are a mere ... guess gadget).

 

Small cases make tube runs and bends a lot more difficult. If you go soft tubing I'd ditch the parallel loop design all together probably as it is pure aesthetics anyway.

 

My new res top came today so I can put in the membrane endcap. Will probably change the fluids within this week.

[MaratM]

On 1/20/2021 at 12:28 AM, KJaboski said:

I also had a mad and expensive idea of using two pumps one for each flow path but fed out of the same res ;D overkill... I know but a way to eliminate flow reduction after the split.

a dual D5 pump is a real overkill. I use a ddc-type chinese noname pump and it is powered from a cpu fan header. the. closest in performance pump is SPC-60 from EK (AOL now). it is a really weak pump (compared to DDC or D5) but it does the job. modern waterblocks are very efficient and the flow rate is not that important as long as water flows it will work.

[KJaboski]

23 hours ago, MaratM said:

a dual D5 pump is a real overkill. I use a ddc-type chinese noname pump and it is powered from a cpu fan header. the. closest in performance pump is SPC-60 from EK (AOL now). it is a really weak pump (compared to DDC or D5) but it does the job. modern waterblocks are very efficient and the flow rate is not that important as long as water flows it will work.

I agree two D5 is definitely an overkill. Out of curiosity is it worth getting a flow meter sensor? One that I can connect and actually have a measurement from it, not a simple spinning indicator propeller thing.

[bowrilla]

8 hours ago, KJaboski said:

I agree two D5 is definitely an overkill. Out of curiosity is it worth getting a flow meter sensor? One that I can connect and actually have a measurement from it, not a simple spinning indicator propeller thing.

Well, data is always good but at most you can make sure that there IS flow so you can catch a broken pump quickly. The only ones that are worth getting are the ones from aquacomputer. Don't even bother with the blinky rest, their readings are at best an educated guess. You'll need their software to run them. They have 2 different types of sensors and they all have a specific range in which they are working and outside that range the readings will have an increasing error. The MPS ones work by measuring a pressure difference which is in theory great but they need a calm and ideally laminar flow (so you will need a stretch of at least 5cm of straight tubing going into it) and you should not EVER add any opaque particles in the loop or they will clog. The other ones have an impeller. Those can be a bit noisier but less prone to clogging up (yet definitely NOT immune). You will also need to make sure to get the right version if you want to run them standalone because some versions are only meant to be used with their controller boards on what they call aquabus and others can be plugged into USB headers. You need to do some research what you want to do and which components you'll need for that.

 

They have a D5 pump that has sensors built in but I have NO idea wether those flow readings are accurate or not. The D5 Next costs also 120€.

 

Imho coolant temps are a lot more interesting than flow rate. You'll usually dial in the pump to a speed that is (just) inaudible to you or at least not disturbing to your ears and leave it at that. More flow can increase cooling performance a little bit but der8auer did a lengthy video (with dubious flow readings though) and the difference between the absolute lowest setting of the pump to the maximum setting was not big enough to be of any relevance as long as you're not either chasing OC records or building a loop with very little radiator surface in a tightly packed system. The fans however should be controlled in relation to the coolant temps and not CPU (or GPU) temps. The coolant temps will not reflect the CPU temps (instantly) and while the CPU might get 20 or 30K hotter the coolant temps are probably just slowly going up by a handful of K over a period of dozens of minutes (it takes quite a lot of energy to heat water up).

 

The only benefit of radiator fans ramping up would be to push more (fresh and cooler) air into the case but that will not significantly influence CPU or GPU temps.

[KJaboski]

On 1/23/2021 at 7:28 PM, bowrilla said:

Well, data is always good but at most you can make sure that there IS flow so you can catch a broken pump quickly. The only ones that are worth getting are the ones from aquacomputer. Don't even bother with the blinky rest, their readings are at best an educated guess. You'll need their software to run them. They have 2 different types of sensors and they all have a specific range in which they are working and outside that range the readings will have an increasing error. The MPS ones work by measuring a pressure difference which is in theory great but they need a calm and ideally laminar flow (so you will need a stretch of at least 5cm of straight tubing going into it) and you should not EVER add any opaque particles in the loop or they will clog. The other ones have an impeller. Those can be a bit noisier but less prone to clogging up (yet definitely NOT immune). You will also need to make sure to get the right version if you want to run them standalone because some versions are only meant to be used with their controller boards on what they call aquabus and others can be plugged into USB headers. You need to do some research what you want to do and which components you'll need for that.

 

They have a D5 pump that has sensors built in but I have NO idea wether those flow readings are accurate or not. The D5 Next costs also 120€.

 

Imho coolant temps are a lot more interesting than flow rate. You'll usually dial in the pump to a speed that is (just) inaudible to you or at least not disturbing to your ears and leave it at that. More flow can increase cooling performance a little bit but der8auer did a lengthy video (with dubious flow readings though) and the difference between the absolute lowest setting of the pump to the maximum setting was not big enough to be of any relevance as long as you're not either chasing OC records or building a loop with very little radiator surface in a tightly packed system. The fans however should be controlled in relation to the coolant temps and not CPU (or GPU) temps. The coolant temps will not reflect the CPU temps (instantly) and while the CPU might get 20 or 30K hotter the coolant temps are probably just slowly going up by a handful of K over a period of dozens of minutes (it takes quite a lot of energy to heat water up).

 

The only benefit of radiator fans ramping up would be to push more (fresh and cooler) air into the case but that will not significantly influence CPU or GPU temps.

Thanks for the info bowrilla. Honestly I have been running a custom loop for 3 years and never considered to have fans on rads react to coolant temp instead of cpu. How could I go about having fans spin up to reported coolant temp instead of cpu temp from fan header?

[bowrilla]

1 hour ago, KJaboski said:

Thanks for the info bowrilla. Honestly I have been running a custom loop for 3 years and never considered to have fans on rads react to coolant temp instead of cpu. How could I go about having fans spin up to reported coolant temp instead of cpu temp from fan header?

If your board has a temp header (most ASUS boards for example) you can have a temp sensor in your loop and usually that can be configured as source for certain (sometimes all) fan headers. If you don't have a temp header on your mainboard, you'll need a fan controller with temp sensor header like an aquacomputer octo, quadro or an aquaero. There are other manufacturers of fan controllers out there but I have no idea about those.

[KJaboski]

19 hours ago, bowrilla said:

If your board has a temp header (most ASUS boards for example) you can have a temp sensor in your loop and usually that can be configured as source for certain (sometimes all) fan headers. If you don't have a temp header on your mainboard, you'll need a fan controller with temp sensor header like an aquacomputer octo, quadro or an aquaero. There are other manufacturers of fan controllers out there but I have no idea about those.

Hmmm admitably I could have looked into these earlier, now that I might be having a cpu/mobo upgrade coming in near future I'll look up available x570 mobos with this type of sensor connectivity.