Questions from a noob - Loop order and a couple other things

[BumpInTheNight]

Hello everyone, long-time PC enthusiast here who's gearing up for my first attempt at a custom loop so please bare with me as I learn!

I've already bought a bunch of parts and I'll go into them deeper but here's the crux of my thoughts: I have two rads, one pump, one CPU block and one GPU with a block - Does it matter in the slightest as to the order I chain them together?

What I want to do because it sounds like it'd be a good idea purely for cooling is: Pump->CPU->Rad #1->GPU->Rad #2->Back to the pump.
From a practical stand point though the easiest loop would just be: Pump->CPU->GPU->Rad 1->Rad 2->back to pump.

I omitted the specific parts from that explanation because I'm really just asking if I'm over-thinking the loop order rather then how specific parts will compliment one another, but the specifics are:
Thermaltake Level20 XT case (its gigantic, I do not anticipate any problems doing any loop order)
2x Ek Coolsteam PE 360 Triple rads and I plan on top-mounting them, the loop order will decide whether I park one or both with their openings near the center or near the back of the case.
EK-Supremacy EVO RGB block that'll sit on a 9900K
Auros 2080 TI waterblock model
EK-Xres 140 pump/resevoir kit

If it might make a difference in someone's opinion I haven't ruled out adding a second GPU later on but as a long, long time SLI enthusiast I am leaning against this round thanks to price and dwindling support in the games I like to play.

[Hooded]

The order doesn't matter unless you're worried about 1/2 a degree in temp as that's about the difference of fluid going into and coming out of rads
2 360rads will handle this OC'ed no issue. Even if you ad another GPU

[BumpInTheNight]

The order doesn't matter unless you're worried about 1/2 a degree in temp as that's about the difference of fluid going into and coming out of rads
2 360rads will handle this OC'ed no issue. Even if you ad another GPU

Awesome to hear and thank you for the quick response

Next noob question if I could: The kit I bought last week came with a 100ml bottle of the Ek-cryofuel and it'll mix to make 1L of liquid, is that more then enough for a first try? I have no idea how much liquid ends up in these. I'm sitting on shopping cart on the store front right now with a few more parts so adding another bottle or two would be easy. Does this stuff 'go bad'? Would it be worth just getting a couple of them right off the bat?

[Hooded]

1 litre should be sufficient but depends on the size of the reservoir. 2 litres will definitely fill it with some leftover .

[Hooded]

Rads require 200ml each
Res filled is 205ml

Tubing and blocks? 1 litre will be very close.

[BumpInTheNight]

Rads require 200ml each
Res filled is 205ml

Tubing and blocks? 1 litre will be very close.

Thank you again! Yah that's what I was wondering and knowing this is my first try I think it'll be better to have a couple extra bottles on-hand for any do-overs

[BumpInTheNight]

New question! I'm trying to wrap my head around how a flow like the one I grabbed off one of your customer build examples (attached). Ignoring the second GPU for sec I guess I'm stuck on picturing how the flow is balanced when the input goes through the GPU, goes to the CPU, comes out the CPU and then back through the GPU block before heading out to the rest of the loop. Wouldn't there be lots of opportunity for the flow to favour one path or another and leave one of the blocks with a relatively stagnant flow vs the other one?

[Hooded]

The loop is set up in what's called a parallel loop.

The CPU block is more restrictive than the GPU blocks.

The fluid is coming in on the left side of the CPU & GPU blocks. The pressure created by the CPU block forces the fluid to flow through the GPU blocks, Some fluid will still flow through the CPU block as well. The fluid comes out of the right side of all the blocks. The tubing is acting like a header collecting the fluid from the blocks on the right side and feeding the fluid to the blocks on the left.

[BumpInTheNight]

The loop is set up in what's called a parallel loop.

The CPU block is more restrictive than the GPU blocks.

The fluid is coming in on the left side of the CPU & GPU blocks. The pressure created by the CPU block forces the fluid to flow through the GPU blocks, Some fluid will still flow through the CPU block as well. The fluid comes out of the right side of all the blocks. The tubing is acting like a header collecting the fluid from the blocks on the right side and feeding the fluid to the blocks on the left.

Got it, so you really have to be confident in that restriction giving each block its opportunity for flow, makes sense now. I think I'll stick to a series setup myself at least for this time but its a very attractive looking design so I was curious about how it worked.

[BumpInTheNight]

Question about the filling process: I've watched enough videos to see people doing several stages of filling their system with liquid, ala fill/pause/fill/pause/top-off etc sequences. If your pump is at the lowest point of the loop what is stopping the liquid from flowing backward through the pump when you pause to add more to the reservoir? Are they designed to prevent back-flow? I mean they must right?

Oh and that creates another question - the draining spot. Since my pump/res is at the lowest point it'll be near that for sure so on either the line heading into or away from the pump, is there an advantage to which one I pick? I bought a T-junction and shut-off valve for this in my first order.

[Hooded]

So there is a ton of ways to go about filling/draining a loop.
I always fill my loop and drain my loop from the lowest point. This can only be done if you have a vent at the loops highest point.
There is nothing to stop the fluid from back flowing through a pump that is not running unless you add some kind of check valve to the loop.
Fluid always finds level. This is why a water level works. Something that has been used for centuries.
You can create air or fluid traps in your loop. The more of these points you have the more often you will have to stop filling and run the pump to push air/fluid through these points.
If you have a vent at the highest point that allows air to escape and avoid some of the traps that can be created.
If you have a rad in the top of your case and it has multiple connections points, then you can use one of those points as a vent, allowing air to escape.
If you don't have the option to have a vent in the highest point then you will need to fill then run your pump etc...
You will have a backflow of water until you get enough fluid in the loop that the fluid in the reservoir is above the downspout in the reservoir. At that point, you need to run the pump in order to push the air trapped in the loop to your reservoir where it can be vented out of the system.

[BumpInTheNight]

Oh wow, okay now I'm so glad to have asked about the drain vs back flow and thank you again for your very insightful knowledge! My top-mounted rads only have two ports so messing around with that would be pretty troublesome. The way I'm picturing now is I'll add two check valves, one on each side of the pump/res so I can isolate it in and use that to bleed off air as it gets displaced with the liquid I add to the top of the res.

A thought I had with the filing is I could put a T-junction between the rads and extend a hose that I can raise above the whole setup to fill liquid/burp air at the same time. Lemmie throw up a picture here.

My current plan for the flow is leaning on pump->CPU->rads->GPU->pump. From the perspective of the picture the CPU block will output into the furthest rad's far connection then come out as a small bridge of tube to the closer rad before coming out of the closest port before heading into the GPU beneath. So in that little bridge I could put a T junction and some tubing that I can tuck away in that space but use it when I want to fill the whole system. If I'm not missing anything then that means I could leave the res's top plugged and just use the same tube for both the air leaving and the water being added simultaneously. While of course still going ahead with a drain at the bottom of the case.

Does this all sound reasonable? One thing about that plan I don't entirely like is that free-floating tube would have to remain held at least higher then the two rads otherwise they're going to dump into it and over all it could be a pretty slow filling process going that route. This is also retaining the idea of using two valves to isolate the res so I can top it off and expel the air that would get trapped in it once the system is nearly filled.

[Hooded]

So if you put a tee junction between the rads and extend a tube above the rads, that would make an excellent vent point.
Now add another long tube to the drain at the bottom.
Bring this tube up the side of the case until it too is above the rads even higher than the vent tube.
Now you're set up to bottom fill the loop. Put your funnel on the tube leading to the lower port.
Leave top port on your reservoir open. Start filling, stop the fill once the fluid reaches the top of the reservoir. Close the open port on the reservoir and continue filling.
Air should be escaping through the vent between the rads. Because fluid always finds level the rads will be the last parts to fill and they will fill evenly. Tip the case a little so the rads ports are higher in order to help push air out of rads through the vent.
Once fluid starts coming up the vent, stop filling from the bottom.
Now start running the system to push any air trapped in rads or blocks. Top up via reservoir fill point.

[BumpInTheNight]

That sounds like a great plan, thank you again for your help! I figure the venting tube would just be a permanent part of the case and I'd put a stopper on the end when the filling is done then tuck it in the gap between the two rads. The long filling/draining tube could get removed afterwards provided I made sure there's a valve which I was planning on putting there any ways. Based on this pic:



I'd pop the venting tube up through the little gap at the far end of the rad mounts and then the filling tube I could bring up anywhere really from the front and tie it off to the frame's edge while that's happening.

[DazMode]

make sure your venting do not overflow and spill on yoru parts. Not end otheeh workd, but will take time to wipe and dry...