Originally Posted by nleksan
Have you decided on the additional radiator? I find that 140mm based rads are almost always the best option if you can fit them, as you are getting a lot more usable surface area forheat dissipa tion (in fact, a 3x140 rad has more surface area than a 4x120!). Additionally, 140mm fans move more air at a given noise level, and while the static pressure is generally a bit less, choosing the right radiator can make this a non-issue.
Having a general grasp of the size constraints, I would highly recommend either the Alphacool ST30 or, preferably, the XT45. Unbeatable performance for the price, with almost completely pure copper construction, the low fin density works with both silent fans and banshees-in-a-box alike, and scale almost linearly with fan speed in terms of watts dissipated. The XT45 280 is a great middle ground in terms of thickness, having the surface area to remove a lot of heat while performing exceptionally well with any fan configuration (push, pull, or push-pull).
I am not a "fan" of Noctua, I hhave justnnever been impressed by the amount of air moved. Sure, they're built exceptionally well and they are indeed quiet, but they're ugly and overpriced in my opinion.
Similarly, I feel that while the Gentle Typhoon series is a solid lineup of fans, they're just so overhyped... They are an excellent "compromise" fan, to me, in that they do everything well enough but they don't excel in any particular area. I also find them to have a rather irritating motor noise, but that's entirely personal and what bothers me may be something you never even notice.
If aesthetics aren't a concern, and based on the Noctua talk I'm assuming that you don't care about the color, I would have to recommend the Cougar fans, at least for the 140mm radiator. The 120mm variant is indeed bested by the AP15, but the 140mm PWM version is the best "quiet" radiator fan I've used.
Noiseblocker is the first choice in terms of quality, aesthetics, noise, and performance based on my interpretation of your noise tolerance level. They're available in 120mm and 140mm sizes, and they truly move a lot of air while making almost no noise.
One thing that I would suggest, based on your having PWM control over all the fans, is to go with a model whose maximum speed (or rather, airflow and most importantly static pressure) is somewhat higher than you expect to need. The reason being that everything will be running off custom fan curves anyway, and it's better to have that little extra juice on tap and not need it, than to realize that there are times you need it but don't haveit. Wi th quality fans like NB's, you won't notice a difference during day to day use, but yyou will have the extra performance available, even if it is just a mental comfort.
In the same vein, I would offer that if possible, push-pull is a good way to increase cooling capacity without increasing noise (you can typically run the fans a bit slower, negating the slightly increased SPL from having more of the same thingmmaking noise), airflow through the radiator will be improved both in quantity and in velocity thanks to static pressure being additive, and you will be getting the best possible cooling at a given noise level for a given amount of rad surface area.
Something that I have found to both cut down on noise as well as increase performance is the use of Phobya 120x7mm and 140x7mm radiator shrouda/decouplers. The shroud effect is well documented, but unlike most, these are made of a rubber material that completely isolates any vibration from the chassis while also acting as a seal, ensuring that all air pushed by the fans travels through the radiatorand even does so more eefficiently by lessening the dead spots created by the fan hubs.
Pair them with some of the XSPC pre-cut radiator gaskets, which have the seal effect and partially decouple the surfaces, for $3 a pop in either 240 or 280 size, and you will have zero air leakage along with further decreased noise emissions. I would use the Phobya between the fans and rads, and the XSPC between the fans and the case. I am running this setup and for the small price it's definitely worthwhile!
Anyway, those are a few of my thoughts, and I hope that you find it helpful.