Custom loop questions

So, i sort of understand that the gains i'd get from a custom loop would be minimal, but i think it would be fun and it looks cool. That said, i want to make sure this kind of setup would make sense.

First, would it be ok to disconnect the radiator from the H115i from the pump and hoses and just use the rad and fans in my loop? If not, no big deal. 280 rads arent very much.

Now, for the loop itself, i have a couple options in mind.

First would have a top mounted 280 rad as exhaust, front mounted 360 rad with the 500D SE fans pulling into it as intake. Loop would be: res/pump, gpu, top rad, cpu, front rad, res. Or just go from the gpu into the the cpu before the top rad.

The question i have with this.... with the former, it seems like the front rad would just be putting warmer air into the case when it cools the coolant coming off the cpu block, but not enough to matter? If the coolant goes straight from the gpu to the cpu, would it be too warm at that point, and would the front rad even do anything?

2nd option would be to forego the front rad, put a 120slim rad at the rear exhaust, and have the loop go like this.. res/pump, gpu, rear 120 rad, cpu, top rad, res pump.

I like the idea of that one, but would a rear 120 rad/fan be able to remove enough heat from the coolant before it goes to the cpu?

So, i sort of understand that the gains i'd get from a custom loop would be minimal, but i think it would be fun and it looks cool. That said, i want to make sure this kind of setup would make sense.

 

First, would it be ok to disconnect the radiator from the H115i from the pump and hoses and just use the rad and fans in my loop? If not, no big deal. 280 rads arent very much.

 

Now, for the loop itself, i have a couple options in mind.

 

First would have a top mounted 280 rad as exhaust, front mounted 360 rad with the 500D SE fans pulling into it as intake. Loop would be: res/pump, gpu, top rad, cpu, front rad, res. Or just go from the gpu into the the cpu before the top rad.

 

The question i have with this.... with the former, it seems like the front rad would just be putting warmer air into the case when it cools the coolant coming off the cpu block, but not enough to matter? If the coolant goes straight from the gpu to the cpu, would it be too warm at that point, and would the front rad even do anything?

 

2nd option would be to forego the front rad, put a 120slim rad at the rear exhaust, and have the loop go like this.. res/pump, gpu, rear 120 rad, cpu, top rad, res pump.

 

I like the idea of that one, but would a rear 120 rad/fan be able to remove enough heat from the coolant before it goes to the cpu?

1) Do NOT modify an AIO (H115i)! It is a closed and controlled environment that uses mixed metals. Not only would this be difficult, it would potentially cause a lot of issues with galvanic corrosion. AIOs get a pass as they have a finite life span and the materials are tightly controlled.

In my case I have a 360mm on top and front. I have my top and front fans setup as all intake and I have a rear 140mm fan setup as exhaust. Airflow in a case isn't as important, when you are cooling all the critical components with liquid. So you are right, by recycling the warm air from the front air means the second rad will be less effective.

I would avoid the rear 120mm rad as rads tends to scale very well in price the bigger you go, at least to 360mm, beyond that they might cost even more. i.e. 120mm = $30, 240mm = $40, 360mm = $50

Lastly loop order is irrelevant. It takes a long time for the water to heat up and to cool off. I can drop a red hot nail into a cup of water and the water will barely register a change, while you can pick up the nail with your hand. The amount of heat that the cpu and gpus blocks generates, compared to the amount of heat that water can absorb is very little. Also, where the heat is exchanges from the block is very small. The radiators on the other hand have enormous surface area. Also ambient air temp plays into water cooling a lot. The cooler the ambient air the more efficiently the transfer of heat from the radiator to the air will occur. The temps regulate themselves very well in a loop.

Other more important things to consider for loop order:

1) Res above/up hill from pump

2) Loop order that allows for ease of draining loop (make sure you include a drain valve)

3) Aesthetics!

4) Avoid long complicated runs, if you can.

My video here might confuse you with the parallel loop, though the RGB lighting does show how things are connected to each other. Just FYI the pump feeds the GPU and CPU via Parallel setup. Then goes into the VRM, then to rads and back into the res. Loop order doesn't really matter.

[ame]

Also Hydro X is coming, beware! I would highly wait till at least CES if you are looking at doing a loop as companies like to announce things then. Corsair picked up EK's top two talents. They tend to do hire really smart people, they hired Jonny Guru a few years back for PSUs.

1) Do NOT modify an AIO (H115i)! It is a closed and controlled environment that uses mixed metals. Not only would this be difficult, it would potentially cause a lot of issues with galvanic corrosion. AIOs get a pass as they have a finite life span and the materials are tightly controlled.

 

In my case I have a 360mm on top and front. I have my top and front fans setup as all intake and I have a rear 140mm fan setup as exhaust. Airflow in a case isn't as important, when you are cooling all the critical components with liquid. So you are right, by recycling the warm air from the front air means the second rad will be less effective.

 

I would avoid the rear 120mm rad as rads tends to scale very well in price the bigger you go, at least to 360mm, beyond that they might cost even more. i.e. 120mm = $30, 240mm = $40, 360mm = $50

 

Lastly loop order is irrelevant. It takes a long time for the water to heat up and to cool off. I can drop a red hot nail into a cup of water and the water will barely register a change, while you can pick up the nail with your hand. The amount of heat that the cpu and gpus blocks generates, compared to the amount of heat that water can absorb is very little. Also, where the heat is exchanges from the block is very small. The radiators on the other hand have enormous surface area. Also ambient air temp plays into water cooling a lot. The cooler the ambient air the more efficiently the transfer of heat from the radiator to the air will occur. The temps regulate themselves very well in a loop.

 

Other more important things to consider for loop order:

 

1) Res above/up hill from pump

2) Loop order that allows for ease of draining loop (make sure you include a drain valve)

3) Aesthetics!

4) Avoid long complicated runs, if you can.

 

My video here might confuse you with the parallel loop, though the RGB lighting does show how things are connected to each other. Just FYI the pump feeds the GPU and CPU via Parallel setup. Then goes into the VRM, then to rads and back into the res. Loop order doesn't really matter.

 

 

Also Hydro X is coming, beware! I would highly wait till at least CES if you are looking at doing a loop as companies like to announce things then. Corsair picked up EK's top two talents. They tend to do hire really smart people, they hired Jonny Guru a few years back for PSUs.

Thanks. Build is in my 500D RGB SE, so top 360 isn't a thing. I feel like with the GPU and CPU on liquid, the ambient temp compared to outside environment would be a pretty negligible difference (if anything), so top 280 as exhaust compared to intake shouldn't really make much of a difference, right?

That said, is the only reason for foregoing the 120 rear rad the cost scaling? The 500D RGB SE can't support anything larger than 120 in the back.

I suppose keeping it simple and just going Res/Pump -> GPU -> CPU -> top 280 Rad (exhaust) -> res would be completely fine. Sounds like tossing another 120mm rad in between the GPU and CPU wouldn't make any difference, but I still think it would look cool and wouldn't really hurt anything, right?

In your situation I would do the following:

Front: 360mm rad (intake)

Top: 240mm rad (intake)

Back: 120mm exhaust

You want to have more intake than exhaust. Intakes have reduced pressure due to filters, rads, bends, and other obstructions. Having one exhaust will help and also give you airflow out of other parts of you case to prevent dust. Just make sure to clean it every 6 months to a year. This should be done in general.

You would be surprised how warm things can get. As the fluid warms up and when you are putting an OC load on the loop, it will heat up. The transfer of heat is proportional to the difference in temperature. So the warmer the fluid is and the cooler the ambient air the more efficient your loop will be.

The price difference between a 120mm and a 240/360 isn't that much. A 30mm rad + 25mm will stick out more than 2 inches from the back of the case. Also with your plan there is a lot of stuff back there like IO shield, end tanks, top radiator and fans. Things can and will bump into each other and even in a well planned loop, you find your designs won't work in practice. The more room the better. You are putting a lot of stuff in the top back of the case, while you have a huge area in the front that will be empty. The build will look a little unbalanced and cluttered in the back, while being empty in the front. Having intake from front and exhausting out top will work, though will be less efficient in general. If you are exhausting out the top, just remove the top filter. You can also run into an issue with negative pressure. I was surprised that in such a situation with 3 intake front and 3 exhaust on top that my 1100RPM exhaust fan was overpowered by the top exhaust. I held a piece of paper to the rear exhaust and instead of blowing the paper the paper was being sucked into the fan inlet. It worked normal if I slowed down the RPM of the top rad, though this was one of the main reasons I switched things around.

Lastly the general rule of thumb is 120mm worth of rad space for each device when NOT overclocking. You want 240mm of rad space for Overclocking. There is diminishing returns on rads, though more rad area past 480mm means you can run your fans at lower speeds for a quieter system.

Thank you so much.

Yeah when i look at that rear exhaust, even a slim rad would start pressing stuff against the board components. It's not too cluttered atm with the top 280. Would there be any downside to top 280 intake, front 360 intake, 120 exhaust (no rad)?

Only reason i ask is because i've already got an extra set of 140s i could use for that, so it would actually be cheaper.

Interesting that your top exhaust was pulling air in through your rear exhaust fan. My top 280 isnt doing that, but i can attribute that easily to the current rad placement, fan speeds, etc.

I've seen front mounted 360s in just about every loop config i've seen in the 500D. Now I know there's a reason for that.