Question Cooling a PC in a cupboard

[Nibbles48]

Hi everyone,

Before i start drilling holes and wasting my time, i thought i'd ask the experts for some advice.

We've just given our home office a makeover and have moved the PC tower, which previously lived on the floor by my feet, into a cupboard. The cupboard itself is about 50cm deep and a metre or so wide, but only has a door at one end (the front-most 50cm or so). Logistically, this means the PC is lying on its side (on the side without any air holes etc.) with the rear of the unit facing the side of the cupboard. A picture will probably help (taken mid-decorating!);

With the door closed this cupboard is fully enclosed, save for a small hole (about 10x2cm) through which the cables are routed. They then route behind the cupboards on the left and up to the desk to the left of those drawers. With the door closed, the PC idles at around 40C, whilst getting up to mid-70s (gpu) fairly quickly when gaming [note i havent done any proper racing with this, but did have the computer running a replay from a previous race to replicate fps/computer load etc.)].

What is my best solution here, to keep temperatures in check. I think options include;

1) open the cupboard door whilst gaming to allow cool air to get to the front of the unit (i could obviously try this fairly easily)
2) replace the panel in the door with some form of mesh/latticing (something like this - https://i.pinimg.com/736x/d5/74/10/...34be0--decorative-panels-decorative-metal.jpg) which would allow air in at the front
3) drill a hole(s) at the rear of the unit to allow air to escape. Note that behind the rear of the unit is a 3inch gap to the wall, but air could perhaps flow left behind the cupboards and edge of the desk, emerging somewhere near my feet.
4) do something similar to the above, with the addition of a fan to push warm air out of the unit
5) drill some air holes through the wall into the garage, either for the air to move to or using some form of extractor fan

I worry that 1 and 2 will only serve to get cool air to the front of the unit, but provide nowhere for the warm air to go (unless i can get it to recirculate with a fan, perhaps). With 3 and 4, will either of those be enough to allow the warm air to escape quickly enough, or does the vent need to be much more significant (hence 5). And if 3 and 4 would be sufficient for the warm air, would it need to be in concert with 1 and 2 (so cold air can get in and warm air escape)?

Alternatively, would some form of water cooling system be a better (though more expensive) solution - or does that also need somewhere for the warm water to dissipate too so is just a case of moving the problem around? I presume i could, in theory, pipe the warm water to a radiator installed somewhere cool (i.e. the garage, through the wall)? But that doesnt sound cheap...?

For context, PC itself is fairly old, i7 870 and a GTX 560 (though i do plan to upgrade in the not too distant future.

 

[DSzymborski]

Unless you're essentially setting up an actual small air conditioner with the unit -- and even that comes with possible issues -- you'll need to have a good way for the hot air to escape. Almost every consumer PC cools the CPU or the desired PC component, not by physically cooling the air, but by heat transfer, that is, transferring heat from the component to the air that is then expelled in some way.

Having the cabinet open will be helpful and you can test. But it may not be enough. There's a reason that most PCs that aren't very light power aren't stuffed in cabinets generally.

 

[TerryLaze]

With the door closed, the PC idles at around 40C, whilst getting up to mid-70s (gpu) fairly quickly when gaming [note i havent done any proper racing with this, but did have the computer running a replay from a previous race to replicate fps/computer load etc.)].

Do some proper testing, if you only get up to 70 you don't have much to worry about.
Also the air flow of almost every case is from the front (where the power button is) to the back of the PC (where the in/outputs are) so drilling holes in the side of the drawer where the bottom of the PC will be won't do that much.

You could just place a office desk fan on the end of the drawer and turn it on anytime you want to, that would clear the trapped hot air from the drawer and as long as it's not a super strong fan it will allow enough new cool air to get into the drawer for the coolers to push into the case.

That is if your case even has input fans.

 

[Moonstick2]

I keep my PC in a cupboard next to the desk with a hole routing cables through. The case has a full front mesh facing the door with a 200 mm fan pulling in and two 140 mm fans blowing out the back, plus a passive top vent. The cupboard doesn't have much more than a few cm either side of the case, with about 20 cm behind it. There is a lot of space above the case though, more than the height of case again, so plenty of space for the expelled warm air to rise.

I've run cards (R9 290, 6700XT) with a significantly higher TDP than yours. Doing light work on the computer, the door can be kept closed, but the door needs to be left open when gaming or doing anything else heavy, or it gets too hot inside. But for my setup, with the door open there's plenty of room for the hot air expelled at the back to rise and pass out, while from your photo I'm not so sure.

How long did you stress your system for? You need to monitor temperatures over an hour or two of heavy running as it takes time for the ambient to build up. You need to monitor all temperatures you can; CPU and GPU for example will probably manage to stay okay since they can crank the fans up (at the expense of noise), but disk drives might get excessively hot since they normally rely on ambient air temperature inside the case.

I would run the PC at load for an hour or two while keeping a regular eye on all temperatures possible (using HWiNFO or similar), first with the door closed and then with the door open. If it gets too hot even with the door open (and take it account how much heat your next upgrade might generate) the first thing to consider would be the case itself. What do you currently have?

 

[Nibbles48]

Do some proper testing, if you only get up to 70 you don't have much to worry about.
Also the air flow of almost every case is from the front (where the power button is) to the back of the PC (where the in/outputs are) so drilling holes in the side of the drawer where the bottom of the PC will be won't do that much.

You could just place a office desk fan on the end of the drawer and turn it on anytime you want to, that would clear the trapped hot air from the drawer and as long as it's not a super strong fan it will allow enough new cool air to get into the drawer for the coolers to push into the case.

That is if your case even has input fans.

Well, i saw 79C temperature of one of the cores after an hour or so running a game (an old one, but one that tends to be more CPU than GPU intensive). GPU got up to about 68C during the same time. Im yet to test it with a benchmark for anything longer than 10 minutes.

It has a fan at the front which i assume is an intake fan. I assume you mean put a fan somewhere in the cupboard towards where the rear of the PC is i.e. so that it moves warm air towards the front. And presumably that would need the cupboard to be open or have a lattice to allow air to come in? I guess i could rig a fan to come on any time the PC itself is turned on?

To be clear, if i was to drill holes inside the cupboard it would be at the rear of the PC, not adjacent to the underneath of the unit.

Unless you're essentially setting up an actual small air conditioner with the unit -- and even that comes with possible issues -- you'll need to have a good way for the hot air to escape. Almost every consumer PC cools the CPU or the desired PC component, not by physically cooling the air, but by heat transfer, that is, transferring heat from the component to the air that is then expelled in some way.

Having the cabinet open will be helpful and you can test. But it may not be enough. There's a reason that most PCs that aren't very light power aren't stuffed in cabinets generally.

Thanks, this is my suspicion. Im hoping that having the door open is sufficient, or drilling a load of holes in the rear of the cupboard is enough to get the warm end out (ideally, but probably not, both)

 

[punkncat]

Something you might consider is a small house fan that you can then open the cabinet door and have that fan blowing into there during gaming sessions?

I have spoken about this to a few posters, but my HTPC is inside the entertainment center which is closed on all sides but the front. I can watch movies, consume internet and such without any issues. Once I start gaming and everything gets heat soaked the situation goes South quite quickly after a point. For instance, I would start out with the temps being high 60's, then drift up into the 70's and then all of a sudden 80+ climbing, throttling, etc. It just gets so warm in there with the air having nowhere to go that it feeds on itself.

I placed a small fan to one side of the enclosure the case is in and it moves the air out well enough that the system typically will stay in the 60-70* range without ever getting so hot.

One other thing, I didn't notice your cabinet appearing like it has veneer, but be aware that if it does and the air gets really hot it will cause the glue on the veneer to pop loose.

 

[Nibbles48]

I keep my PC in a cupboard next to the desk with a hole routing cables through. The case has a full front mesh facing the door with a 200 mm fan pulling in and two 140 mm fans blowing out the back, plus a passive top vent. The cupboard doesn't have much more than a few cm either side of the case, with about 20 cm behind it. There is a lot of space above the case though, more than the height of case again, so plenty of space for the expelled warm air to rise.

I've run cards (R9 290, 6700XT) with a significantly higher TDP than yours. Doing light work on the computer, the door can be kept closed, but the door needs to be left open when gaming or doing anything else heavy, or it gets too hot inside. But for my setup, with the door open there's plenty of room for the hot air expelled at the back to rise and pass out, while from your photo I'm not so sure.

How long did you stress your system for? You need to monitor temperatures over an hour or two of heavy running as it takes time for the ambient to build up. You need to monitor all temperatures you can; CPU and GPU for example will probably manage to stay okay since they can crank the fans up (at the expense of noise), but disk drives might get excessively hot since they normally rely on ambient air temperature inside the case.

I would run the PC at load for an hour or two while keeping a regular eye on all temperatures possible (using HWiNFO or similar), first with the door closed and then with the door open. If it gets too hot even with the door open (and take it account how much heat your next upgrade might generate) the first thing to consider would be the case itself. What do you currently have?

Thanks, this is very helpful.

The height above the unit is about half the unit height - probably about 20cm from memory. So it sounds feasible, possibly with a small fan running to help.

It was stressed (using Heaven Benchmark) for about 20 minutes. I cant find temperatures for the GPU, but the CPU claims Tcase of 72.7C (which i easily get over with the door closed).

I suppose the only other question this raises is whether a door with a panel that allows air through (a mesh or lattice etc.) will be sufficient rather than having to have it open through?

 

[Nibbles48]

Something you might consider is a small house fan that you can then open the cabinet door and have that fan blowing into there during gaming sessions?

I have spoken about this to a few posters, but my HTPC is inside the entertainment center which is closed on all sides but the front. I can watch movies, consume internet and such without any issues. Once I start gaming and everything gets heat soaked the situation goes South quite quickly after a point. For instance, I would start out with the temps being high 60's, then drift up into the 70's and then all of a sudden 80+ climbing, throttling, etc. It just gets so warm in there with the air having nowhere to go that it feeds on itself.

I placed a small fan to one side of the enclosure the case is in and it moves the air out well enough that the system typically will stay in the 60-70* range without ever getting so hot.

One other thing, I didn't notice your cabinet appearing like it has veneer, but be aware that if it does and the air gets really hot it will cause the glue on the veneer to pop loose.

Yes, im coming around to that thinking. Would you mind sending a picture of that setup? This certainly gives credence to the possibility of it all working nicely with a fan to push the air towards teh front.

The cabinet is i think mostly MDF, though the side seems to be a hardwood of some form. When hacking a hole through it with a multi-tool it gave off a fair bit of smoke. But otherwise the paintwork is all satinwood paint only.

 

[Paperdoc]

Even with the front door open and a small fan blowing air into the cabinet, there may be a lot of re-cycling of warm air expelled from the computer rear exhaust fan over the computer and across the upper part of the space, then sucked back into the fan trying to draw room air in from the open front. IF you could arrange a small baffle to prevent warm air up high in the shelf area from being drawn down to the intake of the small fan that may help ensure cool air into the computer case front.

Drilling holes in a panel generally creates very small air flow passages, and you need more than that. Your idea of a decorative front door is better, but any such unit does create air flow restrictions (intake and exhaust) versus an open door and will increase the re-circulation of warm air. A baffle in that case would certainly help.

 

[punkncat]

Give me a moment and let me see what I can do for a picture....

See if you can view this Google Drive link:

EC Fan.jpg

drive.google.com

Very simple solution for my case. Admittedly, the comments made above by Paperdoc are a possibility as well.

 

[Nibbles48]

Perfect - yes the photo looks broadly like what we have (im assuming that the rear of that slot that the unit sits in is sealed, so air has to come out of the front?

I did a log with HWiNFO as suggested above, running Heaven Benchmark for half an hour or so and the door fully open (my wheel and pedals are on the shelf adjacent the pc so airflow probably isnt optimal). Here's a graph of various temperatures

Peak CPU core temperature was 80C for a few seconds, before all the temperatures drop (almost instantly) by about 5C, where they stay for the remaining time. I'm not sure why they drop, fan rpm stays similar throughout and I cant immediately see anything in the log file that would trigger it. The only thing of note is that voltage regulator temperature creeps up to 88C just before then, before gradually then dropping back down (it starts around 65C, peaks at 88C, then settles down at 81C for the rest of the test).

If anyone cares to have a look, I can send the full .csv file.

Ought i to be concerned about the numbers shown here?

Incidentally, there is a TjMAX figure (specifically difference to TjMAX) - is that a set figure from the software, or defined by the hardware? If the latter, that implies that the cpu can get to 98C before it triggers and starts throttling (and that 98C is therefore the max the card wants to ever get to to avoid damage)?

P.S. my memory was poor, the gap above the unit is about the same as the height of the pc (lying down) itself.

 

[Moonstick2]

I don't think you're running for long enough, unless you only game for half an hour at a time. The GPU and motherboard temperatures could be said to still be rising. Slowly, but rising. I'd run it for at least an hour. I also think you should repeat the same test with the PC outside of the cupboard, so you can see how much of an effect stuffing it in there is having.

And monitor drive temperatures as well. They're far less tolerant of heat than CPU/GPU, and don't have any fans to turn up and cool themselves down. Because you're placing a tower case on its side, the disks might not be in the optimal position for cooling now.

It's difficult to say on the CPU/GPU temperatures. The GPU is at the high end for that card, reading around. That drop in CPU temperature does seem like some kind of throttling might have happened, but that's a reason to repeat the test outside the cupboard.

What case are you using anyhow?

 

[Nibbles48]

Hi @Moonstick2

Yes, possibly - though I was going out so didnt want to leave it on unattended. Also, whilst i often game for much longer than that, i dont play anything that stresses the PC to the same extent - none of the games I play would be described as resource intensive. I would test it outside the unit but it took me over an hour to thread the cables through the cupboard and plug them in blindly to the unit, so not keen to repeat that again. Nevertheless, when i've run stress tests previously with the unit out in the open the gpu in particular got fairly warm though not as high as this.

Drive temperature seemed to peak around 39C (had been at 39C for ~15 minutes, having risen from 25C at the beginning of the test). And according to the log, no hint of any throttling (it specifically says 'no')

Case is an NZXT Vulcan

 

[thestryker]

If you're planning on leaving a computer inside an enclosed space like that consider getting at least a couple of USB 120mm fans for exhaust and cutting openings at the back of the cabinet for them. I've used an AC Infinity 120mm fan which is intended for entertainment center cooling for externally cooling a fanless system and it is very good.

For air intake opening the door would probably be the simplest choice, but wide open lattice style like your picture should work. If you wanted to do anything more fine than that you'd likely need intake fans mounted to the cabinet to have enough airflow.

 

[Moonstick2]

Drive temperature seemed to peak around 39C (had been at 39C for ~15 minutes, having risen from 25C at the beginning of the test). And according to the log, no hint of any throttling (it specifically says 'no')

Case is an NZXT Vulcan

39°C is on the warm side again, especially if this is an HDD (which are less tolerant than SSD), but again not too horrific. I think your current setup is okay (with the door open), but you may run into issues with a beefy GPU in future.

That case has a 120 mm intake, right? The side mesh is now on top, which helps radiate out a bit. If you haven't got them already, it says you can fit 2 x 120 mm in the top. That's now the side for you, and if I'm visualising it correctly they'd be blowing into the empty cavity of the cupboard beside the PC. That ought to help cooling quite a bit, and maybe draw more air in through the front.

Or maybe have the base of the case towards the rear of the cupboard, top towards you? You could then have the 2 x 120 mm as intakes, the rear 120 mm blowing out into the larger cupboard space and easier access to the power button and USB ports in the top. It looks longer than it is tall so should fit more easily. Maybe a little less tidy looking with the cables now coming out of the 'side', but they'd also be easier to access then blind fumbling. Provided they can all reach of course.

 

[Nibbles48]

Close. The pc is lying on its side, but the base of the unit is against the front side of the cupboard (next to the door space), with the top facing the back of the cupboard and the rear of the unit facing the left side of the cupboard (as i look at it face on. Im not sure the cables would stretch to connect to the unit if it was turned through 90 degrees.

My feeling is that best bet, for the time being at least, is to run it with the door open and perhaps supplement with a fan (running off USB so on whenever the PC is on) to push the warm air towards the door rather than being 'stuck' at the back. If that fails, an exhaust fan of some form is probably required.

Thanks for all your help. I'll update here if I do anything further.

 

[Nibbles48]

Hi all, happy new year!

Thought i'd provide a bit of an update. PC was running a lot over xmas, albeit not doing anything particularly onerous (acting as a media library for the Sonos system, mainly). With the door closed, the temperature stayed around 60C, even overnight when there was no substantive activity happening (i.e. no music playing - it was esssentially sitting idle). So warmer than i would like, but not too bad. With the door open, it stays tolerable with all things i've been doing thus far though admittedly none of them could be described as 'intense'.

However, my dad pointed out over xmas that the rear of the cupboard in which it is now inserted sits a small distance away, ~15cm, from the wall, and that there is a spacer panel between the bookshelf above and the wall. It dawned on me that there is effectively a chimney where warm air can escape, rising up the side of the bookshelves and out the top.

The solution, therefore, will be to drill some holes in the cupboard to allow that warm air to escape, rather than the warm air having to circulate its way towards the cupboard opening. I may supplement it with a fan attached to the back wall to help the air on its journey to freedom.

I havent done this yet - mainly because it requires me to fondle around at the rear of the pc to remove all the cables - but thought i'd post here 1) to describe the plan and 2) to act as a placeholder for an update when i finally get around to it.

 

[Paperdoc]

Seems a good idea to me. I particularly like the idea that air flow will be through, from front to back, rather than having to reverse and exit at the entrance. Let us know how it goes.