Parallel Cooling?

[DonquixoteIII]

I am going to build myself a new PC - First totally new build in about fifteen years. My case will be a a lian-li pc011 d (PCMR version). I plan on using three 360mm radiators. Yes, I know that there are fit issues, don't care. If al else fails, I do know a good machinist....

My plan is to run the radiators in parallel, using a D5 pump, but might need to run two D5's to get enough flow. At least Martin's chart seems to indicate that. Each radiator will cool one area - CPU, GPU and MB. I plan on using a sort of plenum chamber between the pumps and radiators both in and out, so two chambers total. Attached just behind my front window they might be good 'features'.

Any serious objections to parallel radiators? Other than the obvious one of reduced flows...

As a side note, has anyone worked out a good algaecide that doesn't affect brass?

Thanks,
"the Don"

 

[EarthDog]

Looks like a fun project!

I can't answer the questions, but I want to ask what specific GPU/CPU/Mobo are you cooling. 3x 360mm rads is a ton of cooling and not sure it will yield much over 2x 360mm rads (the problem comes, especially with modern Intel CPUs, getting the heat out of the tiny die, not the capacity. Two 360s can cool 600W or so while being quiet at the same time.

 

[BugFreak]

By a plenum chamber I assume you mean like a distro plate the manufacturers are selling these days? Something like this? If so get ready to spend a bunch of extra cash. Personally I would save some cash and run in series. You will get the same/similar results and have less tubing clutter. I like my builds clean and simple and those things seem to add unnecessary pieces and $$$ for little to no added benefit.

In regards to cooling the motherboard. I don't think adding a whole other 360mm radiator for just that is necessary...or water cooling it at all really. If you are dead set on using water on your board then just add it in series to one of the other lines like after the CPU. I would skip it all together and ensure I had a fan blowing over the heat sink on hot parts personally.

Also with three radiators I would run two pumps. If nothing else for the redundancy and peace of mind but that would be a bunch for one pump to handle imo. I run two radiators with a single pump for my CPU right now without issue but when I add my GPU I will be adding an additional 2x120 radiator along with a second pump.

 

[DonquixoteIII]

Looks like a fun project!

I can't answer the questions, but I want to ask what specific GPU/CPU/Mobo are you cooling. 3x 360mm rads is a ton of cooling and not sure it will yield much over 2x 360mm rads (the problem comes, especially with modern Intel CPUs, getting the heat out of the tiny die, not the capacity. Two 360s can cool 600W or so while being quiet at the same time.

Read my Sig. the '3080' has already earned a rep as a hot beast... Though how anyone knows is beyond mt. Samo for the zen 3 version of the threadripper. Also, I am looking for the next gen AMD GPU. But not too hard...

 

[EarthDog]

If I was you, I would lay off the rumor mill a bit and wait until something concrete comes out on the parts you want to buy. Feels like the cart is running in front of the horse!

 

[BugFreak]

If I was you, I would lay off the rumor mill a bit and wait until something concrete comes out on the parts you want to buy. Feels like the cart is running in front of the horse!

Good advice there. I have a whole parts bin of computer pieces, both cooling and hardware because I planned a build based on pre-release review articles and assumptions. Most became obsolete or unusable when I finally did build it.

 

[DonquixoteIII]

By a plenum chamber I assume you mean like a distro plate the manufacturers are selling these days? Something like this? If so get ready to spend a bunch of extra cash. Personally I would save some cash and run in series. You will get the same/similar results and have less tubing clutter. I like my builds clean and simple and those things seem to add unnecessary pieces and $$$ for little to no added benefit.

In regards to cooling the motherboard. I don't think adding a whole other 360mm radiator for just that is necessary...or water cooling it at all really. If you are dead set on using water on your board then just add it in series to one of the other lines like after the CPU. I would skip it all together and ensure I had a fan blowing over the heat sink on hot parts personally.

Also with three radiators I would run two pumps. If nothing else for the redundancy and peace of mind but that would be a bunch for one pump to handle imo. I run two radiators with a single pump for my CPU right now without issue but when I add my GPU I will be adding an additional 2x120 radiator along with a second pump.

No, I do not mean 'distro plate'. It will be two 50mm OD x 34mm ID 200mm tall. plexiglass tubes. I will mill my own lands for the G 1/4 fittings, as well as drill and tap. Each will have 4 fittings or five if I need to use two D5s.

The problem I have with serial systems covering many water blocks is that in a serial the last block gets to 'suck the hind tit'. In a parallel system each block will receive roughly one third of the flow. I would agree that 3 360s might seem like overkill, but keep in mind that two of the three will have to be thin units, no more than 30mm in thickness, if that, due to case restrictions. As to the motherboard, I also plan to add a block for the SSD raid card as pcie 4 SSDs (so far) run really hot. I will y the output of that radiator to cover both. It is not like I didn't think about this.... "We Do These Things Not Because They Are Easy But Because They Are Hard" - JFK

 

[EarthDog]

In a properly configured loop (flow rate/rad capacity), temperatures at a given point should be within 1-2C of each other so temperatures shouldn't be much different at all. Remember, outside of the res being before the pump, loop order doesn't matter (from Martin's also).

 

[Voodoo Rufus]

I've started to see more parallel systems show up, especially for those running dual GPUs. In general, this is non-ideal for heat transfer. Actually, a straight up loop mistake in my opinion. Higher flow rates transfer more heat, period.

Playing around with loop order to give components the lowest possible water inlet temp is more chasing the last little bit of performance rather than a practical exercise. If you have a lot of components in the loop, and high pressure drop blocks (radiators have a fairly low dP), then go ahead and add another pump to the loop. I have my dual pumps spread out in the system. pump - block - rad - pump and so on. You could also run pump to pump if you want.

If you can find the P-Q curve (pressure to flow rate) for all of your individual components you should be able to come close to calculating where on your pump's performance curve you will land. This is disregarding tubing lengths and additional fittings (90 degree hard fittings giving the worst pressure drop. I hate these). Try to aim for 1GPM or better real world flow rate and you'll be just fine. Anything more is just gravy, and you'd be better served by adding more radiators for high heat loads.

 

[Dr_Emmett_Brown]

Any serious objections to parallel radiators? Other than the obvious one of reduced flows...

No objection. It works best if you vent the heat to the outside, and of course you already know that. It just becomes a matter of internal real estate to keep one set of fins from warming the other.

As a side note, has anyone worked out a good algaecide that doesn't affect brass?

I use glycol so I don't have to worry about that.

 

[DonquixoteIII]

If I was you, I would lay off the rumor mill a bit and wait until something concrete comes out on the parts you want to buy. Feels like the cart is running in front of the horse!

I am PLANNING to build... I am not in the habit of trying to make my horse push the cart, mate.... We DO know that Intel will not be on 7nm anytime soon. They said as much in their earnings statement. We DO know that Nvidia will be releasing a new set of GPUs this year, most likely 3rd quarter. We DO know that AMD will be releasing a new GPU, probably 4th Q... We DO know that AMD will be releasing new CPUs this year, but probably only the Vermeer arch. 1st Q 21 maybe for the Glacial Peak arch. All of the above are either knowns or very good guesses. And NOT by me.

 

[DonquixoteIII]

I've started to see more parallel systems show up, especially for those running dual GPUs. In general, this is non-ideal for heat transfer. Actually, a straight up loop mistake in my opinion. Higher flow rates transfer more heat, period.

Playing around with loop order to give components the lowest possible water inlet temp is more chasing the last little bit of performance rather than a practical exercise. If you have a lot of components in the loop, and high pressure drop blocks (radiators have a fairly low dP), then go ahead and add another pump to the loop. I have my dual pumps spread out in the system. pump - block - rad - pump and so on. You could also run pump to pump if you want.

If you can find the P-Q curve (pressure to flow rate) for all of your individual components you should be able to come close to calculating where on your pump's performance curve you will land. This is disregarding tubing lengths and additional fittings (90 degree hard fittings giving the worst pressure drop. I hate these). Try to aim for 1GPM or better real world flow rate and you'll be just fine. Anything more is just gravy, and you'd be better served by adding more radiators for high heat loads.

I do have some experience with hydraulics, BTW... Pumps in series do not add to the flow rate, just the pressure. Likewise, loops in parallel drop the flow rate by the number of loops. I will try my set of radiators out with just the one pump, then add another pump (in parallel)if I am not getting the results I want. I am also planing on using the Thermaltake TF1 sensors before and after every block to be able to see the actual numbers. My goal is about 2.2 gal/min flow rate.

 

[gregmacknass]

One thing that you have not considered in this design is that fluid dynamics are much like electrical circuits. The flow will take the path of leas resistance in parallel. So in this regard the water blocks with the least resistance in the loop will get the most flow, while the blocks with the most resistance will get the least flow. So you would run into the problem of inadequate flow in the motherboard and gpu blocks, while the less restrictive cpu blocks hogged the cooling.

I would suggest a series configuration on anything that has dissimilar blocks. It is why gpu's can be run in parallel because they are virtually identical.......

 

[EarthDog]

Of course we know things are coming out. My point was that we don't know the wattage/tdp of said parts to properly plan a loop. That said, with 3x 360mm rads, it doesnt matter much!

2.2 gpm is quite a bit... iirc from Martin's testing, 1-1.5 gpm was plenty and above that was notably diminished returns. Youve got an oversized loop so who knows.

 

[Voodoo Rufus]

I do have some experience with hydraulics, BTW... Pumps in series do not add to the flow rate, just the pressure. Likewise, loops in parallel drop the flow rate by the number of loops. I will try my set of radiators out with just the one pump, then add another pump (in parallel)if I am not getting the results I want. I am also planing on using the Thermaltake TF1 sensors before and after every block to be able to see the actual numbers. My goal is about 2.2 gal/min flow rate.

Series pump would not add to maximum flow rate, IF there is no load. Once you start adding a pressure drop, series pumps will flow more than a single.

 

[Rlbol767]

I do have some experience with hydraulics, BTW... Pumps in series do not add to the flow rate, just the pressure. Likewise, loops in parallel drop the flow rate by the number of loops. I will try my set of radiators out with just the one pump, then add another pump (in parallel)if I am not getting the results I want. I am also planing on using the Thermaltake TF1 sensors before and after every block to be able to see the actual numbers. My goal is about 2.2 gal/min flow rate.

Don I am sure you know all about hydro dynamics and I am trying to figure out if you are going on just to hear yourself or if you actually are looking for an answer to your question?
You have gotten lots of good answers!
I am sure you know much more then I about all this however I can tell you my experience since I just built more or less the computer you are planning.

2 weeks ago I finished (or so I thought) a new computer in a ox11d case. Same case as yours in different color but not an XL. My loop consists of an EK water block with D5 pump that replaces the front glass. From the pump that is attached to the distro plate it goes to an EK 240 se radiator in the opening on the side with 2 shallow fans. As I recall they were 18mm which was the largest you could fit with the distro plate and upper radiator. It then returns to the plate. Then the output for the GPU goes to an evga 2080ti kingpin that has to be mounted vertical in the case. It is cooled by the evga hydro cooper water block. Then the out put to the cpu comes out of the distro plate in to the EK/MSI water block to cool the mother board Comp. And intel I9-10900 then goes out to an EK memory water block and then back to the distro plate. Lastly there is an output to the EK 360 pe radiator on the top and then returns to the distro plate. That is the complete loop.

Now as far as the case goes, I would highly suggest you go with the xl if you are going to use all that equipment. The smaller size case will never fit 3-360 radiators! If you have a full-size GPU card you will have to run a vertical mount and then there goes your lower rad. I have to have the upper fans mounted on the top outside of the case to have any room on the top part of the motherboard. I am fabricating a pyramid shape panel to cover the top as well as the three fans on top. With two pumps and resevores you would not have room for any plumbing.
If you look on EK’s website you can download the instruction for there different distro plate for that case and see what they say about what will fit.

I hope this helps you some. And sorry for it being so long winded. I just wanted to make sure that what your planning will work before you spend all that money! Mine went from a pretty simple build to being a huge expense with msi,EK and performance PCs.
Good luck with what ever you do!