Radiator, Fans and enclosure airflow

Hi

Right, still waiting for the Phanteks case RMA which is good. It means I have plenty of time for extra research and planning.

Radiators & Fans
Definitely having 1 x 360 UT60 but can't decide on the second rad. Whether to have a second 360 or go with a 420. I mean, for the 360 I've got a choice of the AP-15 or an eloop (probably going to go with eloops as EUR exchange rate means importing and shipping is less expense than the Scythes). But I can't find a 140 fan for a 420. The only one that really interests me is Noctua NF-P14s redux-1200. Is that any good for a rad? Anyone here used it for their rad and can share their experience please....Are the benefits of having the bigger surface of a 420mm rad negated by the lack of available 140m quality fans, or is it still worth the investment?

As far as the eloops go, I plan to have them push/pull and to have about 2mm of decoupling material to hopefully prevent the pull fans from hitting the rads fins and making a noise. Does that work??


Enclosure Airflow
I'm a bit confused with this and sorry for the totally noob question. Typically, although it varies from build to build, I tend to have a very slight negative pressure inside the case to encourage cool air to enter the case. Now, where I'm confused is the way the airflow moves through the case as I'm going to have a rad at the top and at the bottom. This is my current thinking:

Intakes:
* Front panel (at the bottom)
* Case floor intake passing through bottom rad

Exhausts:
* Rear panel (at the top)
* Case top exhaust passing through top rad

Does this cause a problem? Don't I always want cool air from outside passing into the top rad and into the case for best cooling loop temps? But won't that disrupt the general airflow of the enclosure and go against just letting the heat naturally rise and leave the case of it's own accord? What way is generally the best for keeping both internal case temps good and cooling temps at their best please? This has kinda got me stumped and all spun around (it is quite late now). I know I can experiment to see what works best for my setup, but just wanted to know if there was a general rule of thumb.

Thanks in advance...

Great choices on the rads and fans. I haven't read any reviews on the newer NF-P14 redux for rad use but there may be some out there. You might need to do a little googling. You basically hit the nail on the head with the 140 fans. Although they are coming closer the quality of the 120's they just haven't been around quite as long. The bigger benefit from 140's is they tend to be quieter due to their slower speed. Of course every fan varies.

You have your case airflow correct. We generally suggest intake to be front and bottom with the top and rear for exhaust. If you have adequate airflow your inner case temp will only be a few degrees warmer than ambient. It's really a catch-22. If you mount your rads at the front and bottom you get cool air for your loop, but you'll be dumping all the heat directly into your case.

It is also generally suggested to go with a slight positive pressure. The logic behind this is you don't want your case "sucking" in dust where there are no filters.


I'm hoping to see a build log once you get your case back.

In my experience Noctua fans are not great at all for use on radiators. The current gold standards are the Eloops, EK Vardar or Nidec GT's if you can find them. The Eloops however aren't great when used in push pull and its got nothing to do with the blades hitting fins. The rad fins are a good 10mm at least away from fans. It simply an aerodynamic problem.

140 sized rads will always work much better than 120 sized rads but there is currently far more range in the 120 size, and there are very good fans available. Blacknoise promised 140 versions of the Eloops ages ago but they don't seem to ever be coming. EK has mentioned releasing 140 versions of their Vardar fans which hopefully should revolutionise the 140 market. Of course though if you run fans slow enough any fan is as quiet as another and the 140 size makes that easier.

Airflow for a fully water cooled system works best with all radiators in intake and any others fans in exhaust, even if that is only a single exhaust fan. That provides positive pressure to keep internal dust down if you use filters on rads. Mixing intake and exhaust on rads has the effect of significantly reducing the performance of the rad that is being fed warm air from the intake rad. Although it may seem like having the rads pushing air into the the case could be bad for heat, by keeping the rads supplied with cool air that keeps the water temp as low as possible. That then means that the air going into the case is only a little warmer than the ambient air. If one is intaking and one exhausting water temps will be higher so warmer air is going into the case. Plus with two rads intaking, say two 360 rads, then the interior is getting 6 fans worth of airflow. If one rad is intaking and one exhausting the interior is getting only 3 fans worth of air flow.
So, the difference becomes warmer air and less of it VS cooler air and more of it.

Thanks Blaylock & Jakusfire
Holy cow, this is sooooo infuriating. Now I find myself thinking that maybe I could do away with having the top rad mounted inside the case and have it externally instead. In which case I might as well do the same thing with the bottom rad too which means I now want a different case altogether. How can building a rig be such glorious fun and confusing simultaneously? Anyhow, that will have to be for the next rig. For this one, I'll have both rads working as intake to keep the GPUs, CPU and VRMs nice and cool. I've got a box of fans and can experiment with different exhausts and airflow to see what works best for me in keeping everything else cool before buying some nice quiet (and pretty) case fans.

Jakusonfire said:

In my experience Noctua fans are not great at all for use on radiators. The current gold standards are the Eloops, EK Vardar or Nidec GT's if you can find them. The Eloops however aren't great when used in push pull and its got nothing to do with the blades hitting fins. The rad fins are a good 10mm at least away from fans. It simply an aerodynamic problem.

EK has mentioned releasing 140 versions of their Vardar fans which hopefully should revolutionise the 140 market. Of course though if you run fans slow enough any fan is as quiet as another and the 140 size makes that easier.

Click to expand...

Re the eloops. I've noticed that on another forum, you have the eloops in your sig with 2 rads. What happened when you tried push/pull? Is it noise and if so, is it just at specific speeds due to resonant frequency or whatever??

And as for the Vadars. They are pretty new on the market. I've seen a mini-review from xtremerigs. Have you tried them or know of anyone who has? Need a bit more feedback. Thanks dude.

I finished my Primo build yesterday and it came out nice. I have ST30 360 in the bottom and 240 in the front. On top I have GTX360.
I wanted slim radiators as intake to keep airflow better and a little bit cooler. Air in from front and bottom and out from top and back.
8x SP120QE fans inside the case on radiators. 3 pulling from bottom, 3 pushing from top and 2 pulling from front. I moved all three non led stock fans to the top and kept the led fans in the front.
In the back I have 140mm Bitfenix Spectre fan that I hoped would move less air than it does. I have slight negative pressure at the moment and need to address that.
As for sound levels. All fans run 60% idle and speed up from there as cpu temps rise. It is not very quiet but my motherboard only allows 60% on case fans so I might as well run the PWM hub at 60%.
I will address that too with another pwm hub or just hook up one of my fan controllers.
As for the SP120 fans, They have decent sound profile but the 3 fans on GTX360 like to rattle at low speeds. Even with the included low noise adaptors. It could be that the GTX360 radiator is just too much for the fans to handle.

Just did a little research on your low speed fan rattle. It appears the Phantek UFB Bearing is a fancy name for sleeve bearing.Source:Frostytech.com "The manufacturer describes the bearings thusly; "updraft floating balance bearing". Translation = sleeve bearing." There are debates as to whether mounting sleeve bearing fans horizontally will reduce their lifetime it's likely the cause of the rattle in either case.


Very nice build. Love these cases.

Blaylock said:

Just did a little research on your low speed fan rattle. It appears the Phantek UFB Bearing is a fancy name for sleeve bearing.Source:Frostytech.com "The manufacturer describes the bearings thusly; "updraft floating balance bearing". Translation = sleeve bearing." There are debates as to whether mounting sleeve bearing fans horizontally will reduce their lifetime it's likely the cause of the rattle in either case.

Click to expand...

Nop in my case it's the SP120's. I disconnected the phantek fans and started going trough the SP120's one by one. Only the ones on GTX rad had rattle. My first thought was that it is caused by phanteks fan conroller but they rattle with the low noise adapters connected to 12V too.
I have had similar problems with other fans pushing air trough the GTX radiator. I think it is just too restrictive and causes someking of turbulence or something. They operate fine but rattle at startup and at certain rpm range.