i'd agree but i can only report what i observed. The computer case i was using (Aerocool DS200) has a built in temp sensor and display that i'd never used, but it has about 20" of lead so you could tape it to a number of items, Ram, vrm, cooler base, wherever you chose) - i left it dangling about 5" forward of the air cooler, noctua D15S, and the case has good positive airflow - 3 fans blowing in, 2 exhausting + the gpu exhausting.
When house thermostat was set at 72F, the computer display was showing 71.6F, when house thermostat was set to 74F, it displayed 73.8F. CPU temps were reported by HWiNFO and RealTempGT (RealTemp has always been spot on with HWiNFO, temp wise)
that multiplier effect surprised me, and that was why i tried house temp at 70C, and saw a slightly greater decrease in core temps, not by major amount, but greater than the 74F to 72F drop
i did confirm both the house thermostat (digital) and the computer case's temp sensor/display unit with a non-contact thermometer (laser) that i had here
the only thing i couldn't confirm were the temps HWiNFO & RealTemp were reporting
got a link to skinnee labs tests?
but back to the point of my post, is there anything that suggests exhausting warm air back into the case is neutral in core temp effect, much less not counterproductive. Obviously an air cooler is going to react quicker to a change in ambient temp or incoming air temp, but it would seem like with a liquid cooling system, heat soak would gradually grow when you're re-introducing btu you've already extracted from the cpu
Larry, let me ask a question. That water coolers purpose is to cool the CPU, right? Are you saying that you think the CPU will run cooler if the radiator intakes the warm air that's already inside the case and then exhausts it? That this scenario would be preferred over intaking the cooler, ambient temperature of the room and exhausting into the case?
Larry, let me ask a question. That water coolers purpose is to cool the CPU, right? Are you saying that you think the CPU will run cooler if the radiator intakes the warm air that's already inside the case and then exhausts it? That this scenario would be preferred over intaking the cooler, ambient temperature of the room and exhausting into the case?
exactly, and reason i'm saying that and i'll concede i'm theorizing here, but to push air that has been warmed by btu already extracted from the cpu, back into the case would seem to be using the computer interior and all components like a heat sink, and heat soak would gradually raise the temp of the coolant in the radiators. I understand outside air will be cooler and will cool the radiator more than pushing slightly warmer air thru it and out of the case, but with proper airflow (ie, positive air pressure inside the case) there would be no heat soak building up.
i assume you dis-agree, as you posted the exact opposite up above, and it's not the first time i've seen someone suggest that. One of the things on my agenda, when i get back and finish assembling this system, is to log temps both ways, exhausting the air into the computer and exhausting them out, over a period of time with the identical load on the cpu. It just seems counterproductive to capture btu from the cpu and then re-introduce it back into the computer case.
What you will (likely) find is with a rad using fresh air, the CPU will run a couple of C cooler since its getting ambient air. If it gets case heated air, it should raise 1:1 to the intake temp its getting. So if it was getting 22C intake before and reaching 85C, if it gets 24C intake it should be 87C. Of course, there are lots of variables which can throw that off, but... that is generally how it works.
Either way it's probably only a couple c difference. Think about this larryccf, what is the most temperature sensitive component (CPU). What is the greatest producer of heat (GPU). Maybe in your case they are both around 150w. Either way, you will eaither be applying heat from the GPU to the CPU cooling, or heat from the GPU to CPU cooling. Unless your board has weak VRMs, they are not going to be significantly impacted by the increase in ambient temps.
At the end of the day, the only way to know for sure is to try it. I would definitely be re-arranging cooling before cutting holes if it was my rig.
I agree the temp difference should be just a few degrees either way. However, when you run your tests Larry, please monitor and record your GPU and VRM TEMPS.
What I'm theorizing is by pulling air from the outside of the case and exhausting into the case that your cpu Temps will be about a few degrees less but your gpu, VRM, & internal case Temps will be higher than if you flip the fans around.
Also just a side note...
but with proper airflow (ie, positive air pressure inside the case)
I agree the temp difference should be just a few degrees either way. However, when you run your tests Larry, please monitor and record your GPU and VRM TEMPS.
What I'm theorizing is by pulling air from the outside of the case and exhausting into the case that your cpu Temps will be about a few degrees less but your gpu, VRM, & internal case Temps will be higher than if you flip the fans around.
Also just a side note...
Positive air pressure is not the same thing as air flow. They are quite different in fact.
when i said air flow and then positive air pressure, i was qualifying that the computer's interior would have positive air pressure
as far as the tests, so you're aware, my case has 4.5 intake fans. Three noctua industrial 140mm fans, and one Corsair 140mm, and the "half" fan is a 120x15mm fan i placed in the right side panel centered on the backing plate for the waterblock. Two of the 140mm fans will be under the PSU shroud blowing in, one i've placed, again in the right side panel behind the HDD tray wall - here's a shot
and the rear exhaust fan or what is normally the rear exhaust fan has been reversed so it's blowing, and will have a fan shroud directing it's airflow down onto the motherboard, mainly the VRM heatsinks - and here's a couple of shots of that shroud (2nd shot, shroud has been removed to make it easier to see, as it's clear acrylic
As it is, i've got a 240mm x 20mm rad (XSPC TX240 ULTRA THIN RADIATOR ) with 2 noctua industrial 120mm fans (pull mode) exhausting the air up and out thru the roof, and in the front a 280mm rad (ALPHACOOL NEXXXOS ST30 280MM RADIATOR) with 2 Fractal 140mm fans pulling, exhausting to the outside.
GPU (GTX 1070) will not be watercooled, and even in my current case never ran much beyond warm (40-42C) - I don't game, but render a lot of video files, and the programs i run for the most part rely on the CPU - the GPU is mainly used for viewing work product - only installed it as the motherboard doesn't have a display port. As long as air pressure is positibe, and the GPU isn't struggling to pull in air to push thru it's heatsink, i doubt there'll be any difference in GPU temps
I've thought some about how to keep the analysis even or balanced, i should just reverse all fans but suspect that will keep the case from having positive pressure with rad fans blowing inward & case fans exhausting - i'm wondering if it wouldn't serve the purpose of this analysis to leave the roof radiator fans exhausting to the outside and the 120x15mm fan the way it is, blowing inward, and the floor fans blowing inward as well. WIth just the front radiator (the major radiator) exhausting to the inside, that should show if "heat soak" occurs. If i go the route of roof rad fans also blowing inward, i don't think there's any doubt "heat soak" will occur.
It also occurred to me, that my results may not apply to all layouts, as the number of intake fans i'm running will be unique
Hey all I changed my GPU for a bigger one but now the temps where really out of control so I decided to create my own side panel with a new perspex plate
Two extra fans on the bottom blowing hot air outside my case. Just below my GPU.
Interesting. That bottom intake on the front looks about useless though considering you have an exhaust right next to it.
I'd would have also put the side fans to intake getting more fresh air in and turned up the exhaust. It's a bit counterintuitive on airFLOW...but hopefully you saw some improvements.
Edit: Is the rear fan intake too? So your only exhaust is 2 fans on top?? Turn that rear fan around to exhaust so you have airFLOW.
Interesting. That bottom intake on the front looks about useless though considering you have an exhaust right next to it.
I'd would have also put the side fans to intake getting more fresh air in and turned up the exhaust. It's a bit counterintuitive on airFLOW...but hopefully you saw some improvements.
Edit: Is the rear fan intake too? So your only exhaust is 2 fans on top?? Turn that rear fan around to exhaust so you have airFLOW.
For now I have the top rear back fan as intake cold aor,
The 3 from the rad are also sucking 'warm' air into the case. Because at the front it can't breath
The two on the bottom are exausting right now but I'm still playing around with options.
So all your options are welcome at least I have 2 more options for playing with air flow.
Also I have enough material to make 2 more side panels so if anybody has better ideas for
The place of the fans all ideas are welcome.
Just my personal opinion here but the way I would configure the airflow for this case would be...
Leave the front 3 rad fans as intake.
Reverse the rear fan to Exhaust (set speed curve to max if not too loud)
Reverse side panel fans as intake
Right now you are exhausting the same air that your GPU is trying to use. Looking at the layout the bottom front intake fan is the only fan supplying cool air to the GPU and there are two exhaust fans pushing the air out, essentially fighting the GPU for airflow.
Just my personal opinion here but the way I would configure the airflow for this case would be...
Leave the front 3 rad fans as intake.
Reverse the rear fan to Exhaust (set speed curve to max if not too loud)
Reverse side panel fans as intake
Right now you are exhausting the same air that your GPU is trying to use. Looking at the layout the bottom front intake fan is the only fan supplying cool air to the GPU and there are two exhaust fans pushing the air out, essentially fighting the GPU for airflow.
I noticed, but ill will recheck this, the GPU is pushing hot air in the case so it's blowing it's air in my case and not to the back,
that's why I put the two fans down there to extract the hot air directly from there.
But will try your suggestions because you both advice almost the same
Ok just checked it you guys are fully right the left bottom fan will make it intake.
Maybe I'll make a new panel with just one fan at the bottom taking fresh air inside my case
True, I have both fans as input. And my GPU is now about 10degrees cooler
With changes the fans from exhaust to input I cracked my plexiglass so when my mesh filter arrived I'll make a new one
Thanks again for the suggestions
Do you guys think there is even a better spot for the extra fans or is the bottom not that bad?
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