h115i proper ways to connect push-pull fans

Hi guys!

 

I need to build a push-pull fan set up for my h115i because I mounted the H115i in the intake position and needs more airflow into the case.

 

Right now I need to decide on adding two SP140 LED fans or replace the original and get four SP140 LED. My impression is that if I replace all the fans and get 4 SP140LED, the right way of doing so would be to connect two splitters, one on CPU_FAN, one on CPU_OPT and run both in DC mode in Bios.

 

Here are my questions:

 

1. H115i originally have a fan header from the block that is suppose to connect to the CPU_FAN header, if i disconnected that and used CPU_FAN for the splitter to connect SP140 LED, will that render the pump fan useless? Or will it still be power and controlled by corsair?

 

2. If I just added two SP140LED without replacing the original, would that create any inefficiency in the cooling system? How will I connect it? I can't plug it into the CPU_OPT because CPU_FAN and CPU_OPT are controlled together and since the stock fan is PWM, that means my SP140LED will be running at full speed at all times. Should I connect the SP140LED then to my OPT_FAN header and control it that way? I can't connect it to chassis fans, because all my chassis fans are PWM fans and all the headers are taken.

 

Any input is appreciated!

Anyone?

My main question is "Do i need to plug the 3 pin fan header from the block into the motherboard? If I don't plug it, will my pump fan still get power and work properly?"

If you are determined to go push-pull, use the 4 SP140 LED fans, split as you described between CPU & OPT. Mixing the fans types is probably counter productive. You can get strange acoustics when running one side measurably higher than the other and the slower side may actually contribute some resistance. Also, you will have the control problem you mentioned between PWM and DC motors. I don't know how much benefit you will get from this, so you might as make it look nice with the 4 LED.

 

With the 4 radiator fans on CPU & OPT, you theoretically don't need the pump motherboard lead. The power comes from the SATA connection and the pump will run from that. No CPU-fan boot error since there will be fans on that header. You should be able to go without it, although it will still be dangling. Do keep the USB connection if you want LED control.

thanks for the help c-attack! when i switched to h115i, my mb temp raised by about 8c due to poor intake airflow. by adding the pull fans, i can get some more air into my case and also provide a better case pressure.

 

what if i got a pair of PWN fans? since the cpu_opt header is controlled by CPU fans, would BIOS be able to link the fan speed between CPU_FAN and CPU_OPT fans?

If you get PWM fans, you would have the option of using the motherboard or the pump for control. The catch --- there is only one PWM LED radiator suitable fan I know -- the Corsair ML140 PRO LED. White is pretty hard to come by right now. Blue and red may be obtainable. OPT will run exactly the same as CPU_FAN whether it is DC or PWM control. You don't even have a control option for the OPT. It mirrors the CPU_FAN signal no matter what and there is no way to separate the two. If you are running AI Suite 3, you may be able run one set of radiator fans from a CHA header set to CPU temperature. This is possible on mine, but I don't know if there are any differences on the AMD configuration or you may be on AI 2 and I am not as familiar with its limitations.

 

I am a little worried this won't help the internal temperatures. I suspect most of it is the product of the waste heat from the radiator versus a lack of airflow at all. So you increase your airflow through the radiator. This helps remove a bit more heat from the cooling system. You then dump even more heat into the case, although not a lot more. That heat still needs to be removed from the system. I might tinker with your top and rear exhaust speeds first to see if that has any effect on the motherboard/drive/internal temps.

 

However, that does not mean it is a purposeless action. I normally don't advocate push-pull on a 27mmx280 radiator, but in the front intake position it will allow you to scrub a few hundred RPM off your intake fan speed and keep the same results. It does help with the low speed idle conditions. It could also help displace pockets of air in the case that are blocked from the exit flow (under the GPU, front mounted drives, etc.).

If you are determined to go push-pull, use the 4 SP140 LED fans, split as you described between CPU & OPT. Mixing the fans types is probably counter productive. You can get strange acoustics when running one side measurably higher than the other and the slower side may actually contribute some resistance.

 

Does that mean if you are putting 4 fans on CPU and OPT you should split each push/pull fans as a pair? In other words, which is correct:

 

1. CPU powers both push, OPT powers both pull (or vice versa)

2. CPU powers a single push/pull set, OPT powers the other push/pull set

 

Your post seems to imply #2 is better, since #1 could lead to sound issues.

Assuming all 4 fans are the same, it doesn't matter too much, but my preference would be to put the adjacent fans on the same splitter - push on one, pull on the other. Short answer: this about sound control, not performance.

 

Differences in total throughput on one half of the radiator would likely have little effect on anything and the coolant goes through both. The real reason for this would be to make tiny adjustments to speed between the two sides. On a top exhaust set-up, the "pull set" will be between the radiator and the case mesh/panel. Since it has two surfaces to interact with and in combination with blade proximity and a few other little things, the pull side is often a bit noisier. Reducing the pull fan speed to be a bit less than the push (100-200 rpm) can often make the total package sound a bit more pleasing. This is obviously case specific and 90% of the people out there won't notice a difference either way. You have to set it up one way or the other and this one has a potential use, while I can't think of one for the push/pull pair set up on a double radiator.

 

Also, this post is a bit dated now. There are other 4 pin PWM fans out there, LED, RGB, etc. But the fans in this thread were specifically the SP140 LED, which are 3 pin DC and cannot be controlled from these PWM pump controllers. DO NOT take the SP140L (grey) fans that come with a H115i or H110i and stick them on your motherboard on the same header or in combination with any other fan on a splitter. They have a high current draw and too much for combination with anything. Also, the CPU/OPT advice was Asus specific. Many GA boards have independent control over the CPU and OPT headers.

Thanks! Would a 4 way splitter powered by sata be better for a 4-fan push/pull?

 

Something like these?

 

http://www.swiftech.org/images/products/8-WAY-SPLITTER/CONNECTIONS2.jpg

 

https://images10.newegg.com/ProductImageCompressAll300/35Y-000R-00001-Z01.jpg

The only reason to do so would be because of current draw from the fans. Time to be specific about cooler and fan. If you think it might be off topic/brand, you can send me a private message. The swiftech device looks interesting, but might not be necessary.

Not sure yet actually... considering ThreadRipper + Corsair H100i or H115i using an Asus X399A motherboard and Obsidian 650D case.

 

Still deciding how many (and which type of) fans I want and how best to wire them to the motherboard.

OK then, plenty of time to work it out. There is a solution for most every mounting arrangement, but usually simple works fine. We don't have much real life data on threadripper, but I would certainly lean toward a 280mm radiator over the 240 if you can fit it. You can get by with much less fan speed. My 5930K will pull between 205-220W at full load in its overclocked state. With a 280mm, I can stress test will fans at 1350 rpm and in actual use under 1000 rpm. I would need consistently higher speeds with a 240.

well I have the h115i which I recently moved to be at the front of my case (mastercase 5)

I have a pair of 140mm ML Pro fans on the front and a pair of SP140's on the back, all 4 fans are powered via the coolers fan splitter through splitters and so far I haven't noticed any dodgy acoustic problems, even though the ml's are pwm and the sp's are just 3 pin fans....

 

I am planning on getting another pair of ml pro's for the rear of the radiator and maybe moving the sp140's over too the top of the case as input fans and get another 140 mm fan for the top rear exhaust fan (currently the top and rear fans are coolermaster ones that came with the case and there not up to much) although ideally I would like to just use 140mm ML Pro fans on the case because of the better air movement from them

 

I'm also wondering if the commander pro could be used to run them all from for better control over all the fans but as with everything it takes money and there's always other things to spend it on /