AIO radiator placement

[brucewtb 249]

Does it matter where you install an AIO radiator - top of case or front? Also what direction for airflow?  I plan to install a Corsair 115i pro into Corsair 750D airflow case.  Thanks.

Bruceb

[hovercrafter 10]

I have just assembled a new P3d rig and eventually elected to put a corsair 105 in the front of a Fractal define S. An extra fan was fitted to the front (total3) aimed at the GTX970. At the top of the rig venting upwards I put one fan linked to the cpu/AIO (cpu fan optional header on Strix Z390 H) and kept the standard case fan. result is that air flow is from front to top back thus getting air over the power circuits.

Pleased with the results so far 25C idle under 70 at 5.0ghz (9700K) in P3Dv4.4 basic install (haven't finished the install yet). All the 5 fans are 120/140 mm and run slow enough to not be too noisy.

Hope this info helps.

Gordon

p.s. I WILL one day find out how to update my sig. with rig details

[G-RFRY 1,712]

There are videos on this on YouTube by testers I have mine top mounted pulling in with high performance fans front and back blowing across the GPU and MB, but as test have shown the overriding factor is room temps you cannot cool a PC lower than the room air temps.

Corsair recommend pull method pulling air through the rad form the outside room for best performance.

Edited January 31, 2019 by rjfry

[martin-w 3,235]

11 hours ago, brucewtb said:

Does it matter where you install an AIO radiator - top of case or front? Also what direction for airflow?  I plan to install a Corsair 115i pro into Corsair 750D airflow case.  Thanks.

Bruceb

 

Ingesting air in, through the radiator results in lower CPU temp but potentially higher enclosure temp, thus higher motherboard and graphics card temp. Exhausting air out, so warm enclosure air passing through the rad, results in higher CPU temp but cooler graphics card and motherboard temp. 

Also depends on how you want your enclosure configured, either with positive pressure or negative pressure. Slightly positive is my recommendation, in order to ensure that dust is kept to a minimum. 

As for at the front or on top, there was a very good video a few years back that looked at this question. The conclusion was that at the front blowing in was best for overall cooling. In fact a drop of 10 degrees on CPU temp was observed by positioning the rad at the front of the case, with an open shroud graphics card. Makes sense considering that the rad is ingesting cool air from outside, and that it's not ingesting warm graphics card air from an open shroud graphics card.

So if you have an open shroud graphics card, it may be a good idea to position the rad at the front with cool air being ingested through the rad. 

 

 

 

 

Edited January 31, 2019 by martin-w

[TurboKen 221]

I have the same 280 size radiator and 750D case. Just mount it up top. Along with the twin 140mm fans in the front and 120mm on the bottom it will feed enough air through it, you will have NO problems keeping it cool. I have 11 fans in my 750D (including the 3 on the RTX2080) and it makes as much noise as a modern laptop and still keeps everything cool.

My 4790k delidded running at 4.8 in P3d only hits 60c after an hour of flying.

Also I know there expensive but I use the corsair MagLev fans and they have NO vibration at all.

[G-RFRY 1,712]

Check Gamers nexus test the guy in this video only test two setups and top pushing out not pulling in, pulling in from the top with good rear mounted exhaust fan would have had a different result, if he is right then corsair have got it wrong  and so has gamers nexus and others.

[brucewtb 249]

3 hours ago, turboken said:

I have the same 280 size radiator and 750D case. Just mount it up top. Along with the twin 140mm fans in the front and 120mm on the bottom it will feed enough air through it, you will have NO problems keeping it cool. I have 11 fans in my 750D (including the 3 on the RTX2080) and it makes as much noise as a modern laptop and still keeps everything cool.

My 4790k delidded running at 4.8 in P3d only hits 60c after an hour of flying.

Also I know there expensive but I use the corsair MagLev fans and they have NO vibration at all.

Thanks but is this the airflow through the top mounted radiator in or out?  

Bruceb

[vortex681 806]

3 hours ago, brucewtb said:

Thanks but is this the airflow through the top mounted radiator in or out?

If you have good airflow through the case already (in through the front and out through the rear), having the air flowing into the case through the radiator from outside gives the best CPU cooling.

[martin-w 3,235]

16 hours ago, turboken said:

I have the same 280 size radiator and 750D case. Just mount it up top. Along with the twin 140mm fans in the front and 120mm on the bottom it will feed enough air through it, you will have NO problems keeping it cool.

 

Correct, he will have no problems keeping it cool. But the point is which setup is optimal. 

[martin-w 3,235]

23 hours ago, rjfry said:

.

Corsair recommend pull method pulling air through the rad form the outside room for best performance.

 

Well yes they do, for a reason, it generates the lowest CPU temp. And of course that's what they want us to achieve so that their cooler operates at it's best. Corsair aren't worried about VRM temp, or graphics card temp. 

No rads in my system, but if there were I would seriously consider front mounting and ingesting air in order to keep CPU temps as low as possible. Top and exhausting thus ingesting hot air from the graphics card isn't optimal. 

Edited February 1, 2019 by martin-w

[martin-w 3,235]

12 hours ago, brucewtb said:

Thanks but is this the airflow through the top mounted radiator in or out?  

Bruceb

 

In, if you want the lowest possible CPU temp, but then all radiator heat is being dumped into the case. It wont be a huge issue though. Thing to consider though is that if you also have fans at the front blowing in, and only one at the rear, it will be a very positive pressure. Not an issue as long as the case has plenty of rear venting. 

Out if you want to keep internal case temp as low as possible, then warmer case air is cooling the rad so CPU temp is higher.... however, it wont make a huge difference to temp. What "out" will do though, when positioned at the top of the case, is ingest hot air from your open shroud graphics card. According to the Bitwit video, as much as 10 degrees CPU temp. In terms of case pressure, the bad side of this arrangement is that you may end up with a negative case pressure and more dust ingress.

Why not try both orientations, top and front and test. Easy enough to switch fans around too. That way you will know for sure. 

No matter what you do it wont be a huge issue, The question is what is optimal. For me, if I had rads to fit, it would be front blowing in, for lowest CPU temp and positive pressure. 

Edited February 1, 2019 by martin-w

[TurboKen 221]

19 hours ago, brucewtb said:

Thanks but is this the airflow through the top mounted radiator in or out?  

Bruceb

I have it pulling warm air out through the top as to aid in all the warmer air rising. However Martin is right, it would be more effective to mount it in the front as then you are pulling cooler outside air thru the rad. If your main goal is maximizing cooling for the cpu at some expense of a warmer case. But again with a case this size you will have no problems with heat. Just for a fun experiment I might move my rad up front and see what kind of numbers I get. Then having (3) 140mm fans up top might be very effective anyway.

[vortex681 806]

I don't really agree with front-mounted rads unless you have no other option. With just a fan (or fans, but no rad) in the front, you have a source of cooler, ambient temperature air being sucked in and going straight through the case over the internal components exhausting at the back. You can't beat a straight-through path for the air with cables hidden so as not to interfere with the flow. Top-mounting the rad and pulling ambient air through it will add some warm air to the inside of the case but it then mixes with the cool air from the front fan(s). If you had an inlet fan at the top of the case with a front-mounted rad, the cool air entering the case would miss out anything at the front of the case (like drives) and would have to turn through 90 degrees which is not as efficient as a straight-through path.

[martin-w 3,235]

1 hour ago, vortex681 said:

I don't really agree with front-mounted rads unless you have no other option. With just a fan (or fans, but no rad) in the front, you have a source of cooler, ambient temperature air being sucked in and going straight through the case over the internal components exhausting at the back. 

 

True, but in practice its not an issue. The heat from the rad makes very little difference to motherboard temps, or graphics card temp. Countless AIO's and custom loops get on just fine with a rad at the front. With a couple of top mounted fans exhausting, the warm air is quickly vented, along with the heat from the open shroud graphics card. Rear fan assisting too of course. 

 

Quote

Top-mounting the rad and pulling ambient air through it will add some warm air to the inside of the case but it then mixes with the cool air from the front fan(s).

 

It's not an issue, but if someone thinks rad at the front ingesting warmer air is an issue, then configure top mounted fans to ingest air. Then you will end up with exactly the same scenario, namely warmer front rad intake air mixing with cooler air being ingested from the top. The other point in your example, of course, is that with fans at front blowing in, rad fans at top blowing in and just one fan at the rear, you end up with a VERY positive case pressure and if you don't have the rear vents to cope with it turbulence and enclosure temperature rises. Balanced or slightly positive is optimal. 

 

Quote

If you had an inlet fan at the top of the case with a front-mounted rad, the cool air entering the case would miss out anything at the front of the case (like drives) and would have to turn through 90 degrees which is not as efficient as a straight-through path.

I think you are overstating the case. The front mounted fans and rad aren't an issue, as I said, in practice this configuration doesn't at all cause issues with enclosure temperature. Front mounted rads have demonstrated time and time again that the location and orientation isn't an issue and any increase in enclosure temp is marginal, and of course swamped by the ton of heat being emitted from your open shroud graphics card. 

 

Quote

front-mounted rad, the cool air entering the case would miss out anything at the front of the case (like drives)

 

 Most of us have SSD's these days that are mounted in all kinds of locations and don't generally have temp issues.  Mechanical hard drives don't require much cooling. 

 

Jayz2Cents looked at front mounted rads a few years ago... Conclusion: Not an issue. Barely any increse in temp. 

 

 

Edited February 1, 2019 by martin-w

[G-RFRY 1,712]

I did a smoke test on mine when built the top mounted rad pulling mounted to left hand side not directly over the MB, the rear corsair HP fan 400-2000rpm rated 140mm the air pulled in never reaches the GPU its pulled out the back, assisted by two front 140MM mounted corsair HP fans blowing pulling in blowing across the GPU and MB, the GPU fans never spin until I am in flight and my front fans stop when my PC is idling and all case fans stop on sleep, the fastest the fans have been 1700  in the sim on heavy scenery with PMDG aircraft they have never gone to full.

The top of my case is open mesh and the downdraft caused by the top mounted rad pulls air down over the VRM again tested with smoke, I have an R5 case with the front door removed as tested by GamersNexus resulting3-5deg cooler in his test using a temp probe