Any specific reason why you have the fans pulling air through the rad?
Given the choice of push or pull I'd choose pull. Fans impart not only forward but rotational momentum to the air. Placing the fan in pull helps reduce the rotational element across the radiator matrix, improving flow. I'm careful to seal the fan edges to keep the pressure up, I want the air flowing over the core not the sides. Its a technical vanity, in practise there's not much in it. One improvement would be a shroud to move the fan away from the core and remove the dead spot directly behind the fan motor. I've tried lots of configurations in the past, even 6 fans on a PA120.3 for overkill and tbh its not needed, the open PA design works well with a single high pressure fan (per 120). What's more important is the choice of fan for the application. It can get quite involved.
If you'd like to read more.
http://www.xtremesystems.org/forums/showthread.php?t=137832
http://www.xtremesystems.org/forums/showthread.php?t=171661
http://www.thermochill.com/PATesting/#PA1203
That's a nice solution compared to hanging a rad of the back of your case. Fornowagain will you be using something like some shut off valves if you neeed to move your case or for maitenence? Thanks for sharing though.
I mentioned the cpc quick release at the start, its not apparent what the do. Here's a pic (wallpaper not my choice btw) of the radbox connected to my PC. They are brilliant connectors, a drop of fluid loss and hardly any flow restriction. Just click the button and they separate and seal.
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Parts List.
3 x 120mm x 38mm Sanyo Denki San Ace 109R1212H1011
3 x 120mm x 25mm YATE LOON D12SL-12
2 x Laing DDC3.2 Ultra pumps with PetrasTech DDCT-01s Top
2 x Thermochill PA120.3
2 x CPC Coupling Body cHFCD178-12
2 x CPC Coupling Insert cHFCD228-12
2 x Anodised 120.3 Rad Grill
MEANWELL SP-150 SMPS 12V 150W PSU
Sunbeam Rheobus Controller
Swiftech MCRES-Micro
All tooled up for a my next acrylic project, maybe a custom reservoir or cube case.