Top fans as intake

britain4

britain4

britain4

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I have 3 120mm fans at the front of my case as intake, and no exhaust fans but I do have my Corsair H80i fans as exhausts at the rear of the case and I have two blower style GPUs that also exhaust air.

This seems a good setup except when the system is going at full tilt and I end up with a ton of negative pressure (the front intake fans are running at max speed all the time but that's not particularly fast). I've ordered another couple of fans and was thinking of installing them in the top of the case as intake fans (labelled in the manual as a spot for exhaust fans but it has a magnetic filter so I'm guessing it can be used either way?). I'm fine with negative pressure but another couple of fans would increase the flow of cool air they have to work with but would disrupt the current flow of air from front to back of the case.

Anyway can anyone see any downsides to doing this or have any other ideas on how I should arrange my fans?

The blower style GPUs and H80i exhausting all their hot air outside the case is potentially an ideal setup but it's a shame my temps don't currently reflect that...
 
Well I think you have got a good setup there and with a water-cooled CPU things are a little different to the norm. I would say that top intakes would help towards positive pressure and would also help cool your VRM's and so on. Neither your GPU or CPU are dumping masses of heat in to the box so disrupting the flow is of little consequence, but also I am not completely sure that it will benefit you all that much. I mean blower style graphics cards just run hotter than open style. And don't forget intel 4 series are toasty. All in all you may be being limited here by the style of graphics card and the size of the radiator. Adding all the fans you like won't make much difference. But having said that, positive pressure is a good thing. Since you already bought the fans then try it and see what you get. There may be some buildup of heat from the GPU's so perhaps the extra fans will help. Try it and see!
 
Thanks for the reply. Yeah I know blower coolers will always run hotter, that’s partially what I was referring to. Won’t pretend to know why that is but I’m guessing it’s just down to more air flowing over the heatsinks.

CPU temps are great, even heavily overclocked I’m quite happy with how that runs, just feel like the GPUs could be better as they do run a few degrees cooler with the side panel off.

I don’t believe in the whole “hot air rises so the fans will be blowing against the air” thing as that must be a fraction of the air movement the fans generate.
 
britain4 said:
Thanks for the reply. Yeah I know blower coolers will always run hotter, that’s partially what I was referring to. Won’t pretend to know why that is but I’m guessing it’s just down to more air flowing over the heatsinks.

CPU temps are great, even heavily overclocked I’m quite happy with how that runs, just feel like the GPUs could be better as they do run a few degrees cooler with the side panel off.

I don’t believe in the whole “hot air rises so the fans will be blowing against the air” thing as that must be a fraction of the air movement the fans generate.
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Yes, it does just come down to air flow for the GPU's. Although axial fans push the hot air outside the case, the entire card still radiates infra-red and that will heat up the inside of the case. So yes, it "seems" like you aren't flushing out the effects of the radiated heat, so adding more intake fans may well help. You are right when you say you can ignore the natural flow of the air and force it against it's will, so to speak. Given what you are doing I don't think that "disrupting the flow" will be a problem. I am just wondering where is the air going to get out though?
 
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In the same boat chap.
Also rocking a watercooled 4770k at 4.6, but with an MSI 390X doing the pixels. And a 144Hz 1440p monitor.

Yeah, it gets a little toasty.

My favourite fans are Akasa Vipers, I have half a dozen knocking around. Great flow and pressure, quiet during normal use (and when pushed they ain't too bad), PWM control and reasonably cheap- look for OCUK's bundle deals.
The Piranha 'air-rippers' are also great, got three on my radiator.
 
The 3 120mm fans in the front are RGB ones controlled by the case’s on board RGB controller and I’ve ordered 2 more matching ones - call it form over function but that’s why I’m reluctant to change the fans. I have lots of Corsair SP120s lying around I could try out and see if that makes any difference but it’d spoil the aesthetics of the case!

I’ll keep an eye out for the Akasa fans should I require something more suitable for air flow applications.

Hopefully with this setup there will be lots of positive pressure to keep dust out when the system is not under load (most of the time) and hopefully better airflow when it is under load.
 
Pocah said:
Well I think you have got a good setup there and with a water-cooled CPU things are a little different to the norm. I would say that top intakes would help towards positive pressure and would also help cool your VRM's and so on. Neither your GPU or CPU are dumping masses of heat in to the box so disrupting the flow is of little consequence, but also I am not completely sure that it will benefit you all that much. I mean blower style graphics cards just run hotter than open style. And don't forget intel 4 series are toasty. All in all you may be being limited here by the style of graphics card and the size of the radiator. Adding all the fans you like won't make much difference. But having said that, positive pressure is a good thing. Since you already bought the fans then try it and see what you get. There may be some buildup of heat from the GPU's so perhaps the extra fans will help. Try it and see!
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I think your problem is the case is not designed for airflow. While it has 3x 120mm front fans they have almost no vent area in the thin gap around glass front to draw air from. You only have the top and back venting so I think it's impossible for front venting to even supply needed airflow for a radiator exhausting out the to top and that leaves us with no source of cool air for GPUs. Maybe put some spacers on front to double the gap so front fans can get more air?
 
doyll said:
I think your problem is the case is not designed for airflow. While it has 3x 120mm front fans they have almost no vent area in the thin gap around glass front to draw air from. You only have the top and back venting so I think it's impossible for front venting to even supply needed airflow for a radiator exhausting out the to top and that leaves us with no source of cool air for GPUs. Maybe put some spacers on front to double the gap so front fans can get more air?
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I see what you mean, it’s not bad for airflow but clearly hindered by the design of the front. That said, I have tried running it with the front glass panel off which made no noticeable difference to airflow and no difference at all to GPU or CPU temps - but it could still be hindered by the honeycomb “mesh” stuff.

If you’re referring to my system there I don’t have any fans in the top at the moment, just the rear mounted 120mm rad + blower cards and 3 intake fans at the front. Hopefully with the top fans as intake we should be getting somewhere with more cool air coming in + hopefully being blown towards the cards a bit more
 
doyll said:
I think your problem is the case is not designed for airflow. While it has 3x 120mm front fans they have almost no vent area in the thin gap around glass front to draw air from. You only have the top and back venting so I think it's impossible for front venting to even supply needed airflow for a radiator exhausting out the to top and that leaves us with no source of cool air for GPUs. Maybe put some spacers on front to double the gap so front fans can get more air?
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Fundamentally you are right here. The case is primarily designed to look nice, and look nice it certainly does. I can certainly understand OP's desire to maintain the look.

I am just wondering though if Doyll has hit on a good idea here, if you use spacers to move the side panel away from the case leaving an all round gap, and put your two top fans in so you are positive pressure, then problem solved.

Thing is you wouldn't actually need much of a gap to provide a lot of exhaust so you could do this without messing up the look of the case. All you need are some spacers with the right length and thread. I am sure The Bay would prevail!
 
I suggested spacing front out so front fans get better airflow, but maybe sides too.

Does anyone know what the specs are for the Onyx case fans? Maybe they are low pressure fans. If so higher pressure rated fans would be able to overcome airflow resistance caused by small venting area.

I agree, the back has decent venting area. Removing PCIe slot covers would about triple the airflow in that area. The fine mesh grill in PCIe slot vents is restricting airflow by more than 70%. Wire ring fan guards are lowest resistance and still restrict airflow 29%.
http://www.overclock.net/forum/22657923-post15.html
 
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doyll said:
I suggested spacing front out so front fans get better airflow, but maybe sides too.

Does anyone know what the specs are for the Onyx case fans? Maybe they are low pressure fans. If so higher pressure rated fans would be able to overcome airflow resistance caused by small venting area.

I agree, the back has decent venting area. Removing PCIe slot covers would about triple the airflow in that area. The fine mesh grill in PCIe slot vents is restricting airflow by more than 70%. Wire ring fan guards are lowest resistance and still restrict airflow 29%.
http://www.overclock.net/forum/22657923-post15.html
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I know you were, I just applied your idea to the side panel. I very much suspect the real problem here is the front fans, but as OP has stated, they don't want to change them. Yes it may well help to remove whatever PCIe slot covers, but remember that OP doesn't have many to remove. But anyway, this gives OP lots of things to try. I am sure that something in all this will work.
 
Thanks for the help everyone, some really useful ideas in here! I like the idea of the temp monitor. The guide will come in useful I think, thank you.

I don’t know anything about the specs of the fans unfortunately, the ones that come with the case don’t seem to be listed on their site. Maybe when the additional ones arrive I will have a model number to go on.

Yes with my sound card and 2x GPUs there are only 2 PCIE slot covers I could remove, in between the two 780Tis... worth a shot for a bit of free ventilation though.

Unfortunately as I say removing the front seems to make no difference to temps, most likely due to the equally restrictive (but very pretty) “honeycomb” pattern behind it. I may try some of my Corsair SP120 fans behind there just to see if it makes a difference.

We shall see what happens with a bit more intake pressure from the extra two fans - I’m also replacing the generic thermal paste I used (and the GPU paste) with Thermal Grizzly Kryonaut which might make a couple of degrees difference.

Just in case anyone’s curious...
ObPyQzN.jpg


Now has a H80i in there with the LEDs matching the GeForce logos
 
Yeah, I wasn't thinking about how many PCIe sockets are being used or about the GPUs' having reference / blower coolers. Removing back slot covers probably won't help at all.

But if there is an easy way to space the front TG panel out doubling or even tripling the airflow gap would dramatically lower airflow resistance to front fans and therefore overall case airflow. Ideal spacer would be extension bolts / extension studs (similar to motherboard standoffs) in the same thread as front panel mounts are. which would simply screw onto existing front panel studs increasing the gap by their barrel depth.
s-l300.jpg
 
doyll said:
Yeah, I wasn't thinking about how many PCIe sockets are being used or about the GPUs' having reference / blower coolers. Removing back slot covers probably won't help at all.

But if there is an easy way to space the front TG panel out doubling or even tripling the airflow gap would dramatically lower airflow resistance to front fans and therefore overall case airflow. Ideal spacer would be extension bolts / extension studs (similar to motherboard standoffs) in the same thread as front panel mounts are. which would simply screw onto existing front panel studs increasing the gap by their barrel depth.
s-l300.jpg
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I’ll try removing the front panel again and seeing if it does anything to temps. I still think the cutouts in the metal behind it will be more restrictive though and I don’t want to cut any metalwork. I do like the idea though, if it does make a difference I’ll be doing it.

That Noctua fan looks pretty impressive - the 120mm one would be worth considering. There seem to be more cases making use of 140mm fans these days which is great but alas, not the one I’m using.
 
https://www.techpowerup.com/reviews/XClio/3060Plus

I got this case years ago with my previous build. Unfortunately the massive 360mm side fan stopped working years ago and couldnt source a replacement. Thats why i started looking for other fans to fit. I had to bend a bit of metal inside to get the new 140mm fan in the front as all the fixings inside were riveted. Bent back fine though and does a job for me.
 
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