Airflow..

[sx_turbo]

hi,

it's likely been asked a few times before, however i cant find any clear answer. I do have experience in building gaming PC's but i must admit its been around 10 years since the last time i built on and things have moved on a bit since.

i'm building a gaming pc within and ikea alex unit, i'm just getting things ready for when the parts will be available. i've converted the drawers to fronts only and hinged them already. i'm now turning my attention to the air flow.

the unit has plenty of gaps in the front to allow air to be sucked into the case, and i'm going to cut the back out for where the PSU will sit.

i'm planning on using an open frame kit to mount the components inside. attached to this will be a 240mm arctic AIO radiator at the front, and i am planning on installing 2x Noctua NF-S12B (100cfm each) PWM fans in the side of the drawer unit towards the rear.

the main components inside will be zen4 7700x and a rx6700xt (or amd latest version of)

would my plan above be sufficient for air flow?

 

[Tired9]

I am assuming this?

It's terrible for airflow.


Taking the back out is a good idea but no those gaps are not enough, You could take a drawer or two out to the height of the PC and instead staple in some mesh material that is easy to dust off.

 

[sx_turbo]

I am assuming this?

It's terrible for airflow.


Taking the back out is a good idea but no those gaps are not enough, You could take a drawer or two out to the height of the PC and instead staple in some mesh material that is easy to dust off.

Yeah that's it,

I don't think it's too bad air flow wise when comparing to other proper pc cases available (lian li 170m) the slots that are handles in the Alex unit are quite large, the pc will be built "case less", I'm sure with some light modification it will be fine.

If it doesn't work I can just open the door. Though dust will be another issue. I was going to fit dust filters to the door, but again airflow,

Any way, do you think what I'm proposing might work, or should I install more fans

 

[lsg1r]

I've had a few pc's in desk 'compartments' and while I've found the air coming in is fine, even with a pc case around the parts, the air going out the back doesn't always work well and you get a hotspot at the rear of the unit, especially if it's going up against a wall. Note I did not use high tdp stuff and amd 7000 series are higher tdp than the 5000 series etc....


If it was me, I wouldn't be going aio, I'd be using a tower cooler with air flow going front to back of the unit, trying to incorporate a few fans at the 'front' and the 'rear' as well. I'd do this to try and encourage a natural 'air circulation' which imo will be the biggest issue and a 240mm fan will act a bit like a 'blockage' even with air flowing through it. Depending on flooring (and feet depth) you could always drill some holes in the bottom (I assume it's going in the bottom) and have some fans pulling air in from the underside (you could add a dust filter) although if your floor is carpet I wouldn't do it for obvious reasons.

 

[sx_turbo]

Thanks, I'll do a bit of designing

 

[Mr Jack]

I'd been thinking about doing a similar thing in an old, solid wood desk for a while. One day, I might actually do it. I disagree with @lsg1r: I think AIO (or custom watercooling) is the best approach. Put the radiator at the back of the unit, with more fans at the front, so that you have airflow from front to back. Putting the radiator out there means all the heat being dumped to the back of the unit and reduces the amount of heat in the PC itself. I don't think you'll manage the same level of airflow you get in a normal case so it's going to be tricky to get the cooling right.

 

[sx_turbo]

Been doing a bit more research, from the info I can find, going air cooled is the correct way in restricted environments.

I'm going to get a duct made by vacuum forming for me to fit on the drawer fronts that I've made into a door. On this shroud I'm going to install 3x 140mm noctua fans.

At the back I'm going to cut out for the PSU to exhaust.

On the left & right side of the cupboard towards the front I'm going to put a noctua 120mm fan to blow cool air in.

The upper right side rear I'm going to have another noctua 120mm fan as an exhaust.

On the CPU I'm going to go for a noctua nh-15 fan cooler.

Hopefully this should keep everything in check and work quite well.

I'm just doing a drawing so I can send off the file to the vacuum forming co for my front duct. And I'll get the fans on order.

Just need to decide how I'm going to mount everything, I'm now thing of mounting the motherboard to drawer rails to make servicing the components easier, I can just disconnect the power supply and video cables and slide the components out the front

 

[lsg1r]

snip

Am I understanding this right...

No open back to unit?
3x140mm at the front pulling air in (I assume) via the handle gaps - intake
2x120mm fans at the front on the side - intake
1x120mm fan rear top right - outake
CPU fan front to back I assume.


You're going to have issues getting the air/heat out imo, there just isn't enough output volume from 1x120mm fan and psu fan (if you're lucky) if you don't have anywhere else for the air to escape from.
You've basically sealed up the front with the shroud, the side fans are pulling air in and all you really have is a single 120mm fan trying to pull out 5 fans worth of intake... if it does work you'd have one very noisy out fan

I'd switch the 2x120mm from the front sides to the rear sides of the unit or even look at 3x120mm fans in a vertical line on one side and if the back is sealed you can even add in a curved bit of plastic on the other side to the fans channel air better.
If it was me I'd be aiming for equal in and out air volumes or even slightly (iirc) negative pressure (more out than in)

 

[sx_turbo]

Am I understanding this right...

No open back to unit?
3x140mm at the front pulling air in (I assume) via the handle gaps - intake
2x120mm fans at the front on the side - intake
1x120mm fan rear top right - outake
CPU fan front to back I assume.


You're going to have issues getting the air/heat out imo, there just isn't enough output volume from 1x120mm fan and psu fan (if you're lucky) if you don't have anywhere else for the air to escape from.
You've basically sealed up the front with the shroud, the side fans are pulling air in and all you really have is a single 120mm fan trying to pull out 5 fans worth of intake... if it does work you'd have one very noisy out fan

I'd switch the 2x120mm from the front sides to the rear sides of the unit or even look at 3x120mm fans in a vertical line on one side and if the back is sealed you can even add in a curved bit of plastic on the other side to the fans channel air better.
If it was me I'd be aiming for equal in and out air volumes or even slightly (iirc) negative pressure (more out than in)

Yeah that's essentially it,

Not sure how to add pictures on here, thinking on it one of the front fans will be too close to the wall so I've removed that.

And I've upped the size of the single rear fan to 140mm plus the PSU (but have no problem putting 2x 120mm fans instead)

I was always under the impression that it was better to have slight positive pressure from what I've read/watched, it also how we run our engine test cells at work.

 

[lsg1r]

I was always under the impression that it was better to have slight positive pressure from what I've read/watched, it also how we run our engine test cells at work.

Different fields will likely have differing views, I'm coming from a product design background rather than a pure engineering one so.....either way I still think your original plan will have a hot spot and you'll need to increase the 'out' air. Remember you're not going to be running low heat output components

As to images upload to online imagehost (imgbb.com for example - free option) and link it here using the insert picture icon next to the smiley face or using bbcode.

 

[sx_turbo]

Thanks for your help.

I'll add an extra fan, I'll probably go for 2x 120mm at the rear then, I can always add if required, or turn one off / reduce the speed of required also.

This is a rough sketch of what I'm proposing. The top drawer is staying.

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Image IMG20220920204807 in Sx-turbo's images album

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[lsg1r]

Thanks for your help.

I'll add an extra fan, I'll probably go for 2x 120mm at the rear then, I can always add if required, or turn one off / reduce the speed of required also.

This is a rough sketch of what I'm proposing. The top drawer is staying.

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Image IMG20220920204807 in Sx-turbo's images album

ibb.co

Lose the front side intake, move it to the rear for 2 extract.

Not sure on length of motherboard vs drawers but can you rotate the psu onto it's side so the fan is pulling air in the same direction as the rear fans? If you can it would create a nice 'matching' air flow route.

Looks like your motherboard is vertically mounted.... can it go the other side? The air would then be naturally pulled away from the motherboard by the out fans being on the other side, although this might not be best for the gpu.....

 

[sx_turbo]

Yeah can mount the motherboard the other side no problems.

Thanks for your help, think I have a plan now.

 

[boabs]

watch a vid on u tube called dawid des pc case in cupboard.

 

[sx_turbo]

I've got the fan shroud made, unfortunately they couldn't make it with thicker material so it ended up being vacuum formed in .75mm lexan, which is strong enough now it's molded to hold everything, where the fan holes have been cut it's a bit flimsy, so I've had some metal plates laser cut I'm going to glue to the images of the shroud and screw to the fans.

I've bought all the fans now, just need to cut holes in the rear.side for the 2x 120mm fans and mount them.

I'm now looking to mounting the actual pc equipment.

My plan was to use a veddah grinder ac-1 pc frame, but they suddenly seem a less available than they were, there is also next to no information available for the case in terms of dimensions etc.

Is there any alternatives I should be looking at?

Also with amd's announcement of the non x 7700 CPU I'm wondering if this may be a better proposition, though the price isn't a great deal cheaper than what OC is currently selling the 7700x for. Although I do count it would be £100 cheaper as I wouldn't have to buy a noctua cooler to cool the 7700 as I would the 7700x. However I do have concerns over the supplied cooler, will I end up installing the noctua air cooler anyway?

I'm now also struggling with GPU choice. I was going to get amd 6750xt, however I fear I'll regret this choice as next gen gpu's are due to release this year (when we don't seem to know and at what cost.

Lastly I was going to get a super flower leadex 3 850w PSU, is super flower a good brand? It's an 80 plus gold unit.

Sorry for the long post

 

[lsg1r]

My plan was to use a veddah grinder ac-1 pc frame, but they suddenly seem a less available than they were, there is also next to no information available for the case in terms of dimensions etc.

Is there any alternatives I should be looking at?

Maybe look at an pc open bench setup

 

[sx_turbo]

I've got quite far with it now, I've finally ordered the components just waiting for the. To get here then pluck up the courage to install it.

This is what I've got so far.

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I've since cut a hole under the PSU for the auxiliary cables to go through and installed a brushed cover for the cables to go through and the brushes cover the gaps around the cables to try and seal the case so warm air isn't drawn through.

I have made some errors during the modding of the case, its a learning process and I know next time.

 

[pastymuncher]

I think you are really going to struggle to get enough airflow into the case as those hand holes in the drawers simply don't look big enough.

On a side note, what are you using as the motherboard base? Is that a open bench chassis or something?

 

[sx_turbo]

Error post

 

[sx_turbo]

it's an open bench chassis.

We'll see about the air flow, I've seen less on some Lian li and other cases with plain faces.

If it comes to it I'll just open the door.

I'll have the PSU and 2x120 mm fans sucking fresh air aswell from the gaps around the door and the top drawer.

Bit of luck I'll be able to let you know in a couple of weeks.