Wiring Question for Air 740 Build with 11 or 13 fans + RGB

Hey folks!

I've read a lot in the past days on the web and especially in this forum (yes I've read Zotty's the really helpful FAQ), but I still have some unanswered questions about my coming build. I've planned to build my system water cooled and with RGB. It was a constant back and forth for me between a discreet system with something like the Carbide 275Q or a lighted up Air 740. But I've had an eye on the Air 540 since it was released indeed. Since then a few years passed, I know, but I wanted to wait with a new build until my current system (Laptop) wouldn't have enough power for me anymore – this step has been taken right now.

I've got a delidded i7-4790K and 4x 8 GB RAM (Crucial Ballistix Sport) from a friend of mine and bought an ASRock Fatal1ty Z97 Killer 4 or 6 weeks ago. In the same step I bought a GTX 1060, unfortunately not a PCB design. Maybe I would buy a i7-7700K or i7-8700K second hand with Z board and a GPU in reference design as well as the Corsair Vengeance RGB RAM in a year or two. But my current configuration should enough for now.

I want to set the following build up:

• H150i with 6x LL120 (push/pull) in the front as intake
  
• 2x LL140 on the top as exhaust
  
• 1x LL140 rear as exhaust
  
• 2x LL140 on the bottom as intake
  

If I'd buy a new GPU in reference design, I'd also want to buy a H115i for it and place it in the top. Here's my first question: Does the Air 740 have enough space to place a H115i with 4x 140 mm (push/pull) and a H150i with 6x 120 mm (push/pull) in the front at the same time?

As you can see all the fans I've chosen does have RGB. In addition to the fans I'd buy a RGB LED Lightning Pro Expansion Kit with four LED strips.

RGB: I would connect the six LL120s in one RGB Fan LED Hub and the five LL140s in another RGB Fan LED Hub, which go into LED channel 1 and 2 of a Commander Pro. The LED strips should be connected with the USB port of the Commander Pro, is that right? Second question: What if I buy two more LL140s for the H115i I've considered one day; do I need one more Commander Pro or is there another option?

PWM: The five LL140s would run directly through the Commander Pro. If I get the H115i in push/pull I'd have one fan too much for this. It should be possible to use a PWM splitter like a Y cable on the Commander Pro so I'd do so.

My mainboard has a 4 pin and a 3 pin connector for the CPU fan(s). As far as I could see the H150i uses the 4 pin connector for two fans (Y cable) and the 3 pin connector for the third. But what about the additional three fans on the radiator? What if I use a Y cables for some ports on the Commander Pro (just two fans per port)? I don't understand how the three rear fans of the radiator would adjust their speed with those on the front of it.

I hope you guys can shed light into my darkness.

Hey,

thanks for your reply. What kind of clearance issues do you mean; could the pull fans of the H150i block the pull fans respectively the radiator of a top mounted H115i?

If I'd buy a new GPU in reference design, I'd also want to buy a H115i for it and place it in the top. Here's my first question: Does the Air 740 have enough space to place a H115i with 4x 140 mm (push/pull) and a H150i with 6x 120 mm (push/pull) in the front at the same time?

It will be extremely tight and I can't guarantee it will fit -- at least not without some modification. The photo below is my solution to this and I run dual 280mm and you can see there is just a few millimeters to spare. Even with the 280mm top pushed back as far as possible, the space for a 27mm radiator and 25mm fan in between that and the front rail is very tight. My HW Labs 280mm is pushed to the very top taking up near the same space for height. You might consider forgoing the 360mm and take a H115i Pro/Platinum or other 280mm cooler. The 740 is made for this and a 280mm can go top, bottom, or front. You have multiple placement options and enough flexibility to run 3-4 different kinds of set-ups. There will be no difference in cooling between a 360mm and 280mm for your CPU, nor for my 8700K.

http://www.mediafire.com/view/f296rp3y3p20s20/IMG_1542.jpg/file

Push pull is likely out for both, although you absolutely don't need it. Even on my Titan loop at 350W, the coolant delta is +10-12C. No reason to double up fans to make your GPU run 34C instead of 35C. This was for someone else originally, but you can see the second fan held in place below to simulate push pull on the front. Top is going to be a no go for almost all recent motherboards.

http://www.mediafire.com/view/xu74zukrqj9s749/IMG_1543.jpg/file

RGB: I would connect the six LL120s in one RGB Fan LED Hub and the five LL140s in another RGB Fan LED Hub, which go into LED channel 1 and 2 of a Commander Pro. The LED strips should be connected with the USB port of the Commander Pro, is that right? Second question: What if I buy two more LL140s for the H115i I've considered one day; do I need one more Commander Pro or is there another option?

 

PWM: The five LL140s would run directly through the Commander Pro. If I get the H115i in push/pull I'd have one fan too much for this. It should be possible to use a PWM splitter like a Y cable on the Commander Pro so I'd do so.

 

My mainboard has a 4 pin and a 3 pin connector for the CPU fan(s). As far as I could see the H150i uses the 4 pin connector for two fans (Y cable) and the 3 pin connector for the third. But what about the additional three fans on the radiator? What if I use a Y cables for some ports on the Commander Pro (just two fans per port)? I don't understand how the three rear fans of the radiator would adjust their speed with those on the front of it.

The H150i or H115i coolers have their own fan controller and so those will not need to be on the Commander Pro for fan control. Push pull is going to be out anyway, so that further reduces the number for control. The other side of the equation is lighting and that power comes through the RGB lighting hub. You are limited to 6 per hub. If you were to go to 7 or 8, technically you would need a second hub and a Lighting Node Pro (LNP), but not a Commander Pro unless you needed more physical fan speed control. The C-Pro does both jobs. The LNP only interfaces the RGB lighting hub with the software. Either way, some people are able to split an extra fan or two off the one RGB hub, although I suspect that makes sequenced patterns slightly off at the end. Either way, this sounds like a down the road problem. To start, you would only need the 5-6 LL fans and a Commander Pro to get both lighting and software fan control from within iCUE.

Thank you very much for your detailed answer.

Well in that case I won’t run a push pull setup. To be honest I actually wanted to buy a H115i for my CPU, but I’d love to see three RGB fans in the front. But getting rid of the doubled fans on the radiator(s) avoids further issues.

I think 360mm front intake, 280mm top exhaust will work. However, the hoses themselves become the limiting factor. In this kind of system, you absolutely want the GPU waste heat to exhaust, so that makes the top H115i for the GPU and front 360mm for the CPU with hoses on the bottom. However, the hoses on the bottom will prevent you front putting a 280mm radiator on the bottom fans. Just something to be aware of and not necessarily a prohibitive obstacle. That front CPU rad intake, top GPU radiator exhaust is also likely to be the most efficient for case management.

I wanted to run an all 140mm set-up and it had been on my to do list for a long time. However, to make that happen in a sensible way I ended up with this reverse flow bottom/rear intake, top/front radiator exhaust. It likely costs me 2C in internal case temperature, but since that peaks out at 32C in Summer, other options with the dual 280mm radiators became somewhat moot. It also makes all the RGB fans visible to me since I keep the case at a right angle, rear I/O side pointing at me. One of the things you may want to look at is what happens when you front mount a 280mm on the Air 740. It has some rather annoying spacing for 140mm fans that likely force you to mount them on the inside. While not overly relevant for performance, it does certainly change the RGB look of the front fascia. I like the 740 a lot, but one of the things I have never liked is how RGB fans shine through the front. For whatever reason, I prefer the front fans dark or non-LED with the rather complex mesh front panel. Personal preference. Compare the above to the H150i and the 120mm fan mounts that are evenly spaced and as expected. This makes it your choice on the fans - inside or outside. That may have some bearing on your decision.