Blowing in or pulling out

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Iwf

Iwf

Iwf

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I’ve question about air circulation.

I’ve a loan li mini case, and a single 280mm res with water blocks on my ryzen cpu and 3090 FE gpu.

Standard guidance suggests I pull in fresh air through the rad fans (2 * noctua 140 industrial) and expel air out the back or top, with perhaps a second fan usb over the MB to keep that cool.

but wouldn’t I better simply having all the fan pulling air out, replying on enough fresh air being pulled the the case
 
You'd be correct if the only place you could pull air in was such that it meant all your components experienced some airflow, however it won't be like that. It also reduces dust intake; keeping things roughly even - or slightly more intake than exhaust - prevents a negative air pressure scenario whereby air is sucked in through unfiltered channels.
 
Maybe I’ll orientate the fan above the MB to pull air from the top and set everything else to exhaust. I’m also wondering about a second rad, but the single 280 seems to be able to hold temps down.
 
Please don't set everything to exhaust. One, you're expecting all the air to come in through non-fan points which usually means heavily constricted and without filters.

Rad at the front (my preference is pulling through the radiator rather than pushing because it's easier to clean the rad), and a fan at least at the back exhausting.
 
Exhaust.
Once the biggest offenders are watercooled, the other components won't increase the internal temperature of the case that much to the point of crippling your radiator performance. My only concern is a single 280 for anything plus a 3090.
To prove my point, just check how hot the air passing through the radiator gets under load.
Are you comfortable blowing that air at the back of your already got backplate and increase the temperature around it?
 
Also create a path for airflow.
Don't recommend all intake or exhaust. Balance. Direct the airflow, don't expect the air to find a way out. You don't want to creat dead spots.
 
Axial fans are rubbish at pulling, but pretty good at pushing. So they need to push air through the rad. Convection forces are so tiny they can be ignored. So your (I'm assuming) 2 x 140mm fans should blow room air through the rad. Even if it means blowing down. If you have other fans, then the overall you need to balance the fans blowing in with those blowing out. But more in than out if you can't.
 
Great advice, more in than out, but roughly balanced. I guess also it needs configuring for what you’d want it to perform , hear like, in use.
One question though, in terms of exhaust, given the number of ventilation holes, should I attempt to restrict the airflow to just the fans?
 
I've never bothered. And if you do, it would defeat the point of more in that out. Since the fans can't push hard enough to raise the case pressure to any measurable degree, then the extra air needs to escape. If it can't, the rate at which air is pushed in decreases.
 
personally I think the best answer to your question "blowing in or pulling out" is "both". Wherever possible I like to have the first radiator after the cpu/gpu to be an exhaust radiator in the roof and then to an intake radiator in the front. The top rad does most of the cooling and dumps the heat outside, the front rad is lowering the water temp that extra touch but not to the extent of heating the inside of the case too much.
 
MikeTimbers said:
personally I think the best answer to your question "blowing in or pulling out" is "both". Wherever possible I like to have the first radiator after the cpu/gpu to be an exhaust radiator in the roof and then to an intake radiator in the front. The top rad does most of the cooling and dumps the heat outside, the front rad is lowering the water temp that extra touch but not to the extent of heating the inside of the case too much.
Click to expand...
That's exactly my approach.
If anyone is planning a single rad setup, and that rad would be struggling to cope, where few degrees is make or break, then I would say intake...
But for 2 or more rads, 99% of the time, first you get rid off most of the heat, then you bring air in/use air cool as possible to drop temperature as much as possible.
In the past, having exhaust after intake rad just cancelled any benefit of the extra rad, as the coolant was close in temperature to the air available for it to use.
Kind of a tedious task, but with the O11 XL I've tried every possible combination, and works best as Exhaust after blocks, intake and intake. Pump/Reservoir can be anywhere in between. Mine is between two intakes.
Just changed here for exhaust after GPU, then CPU to first intake (to simplify tube routing) as the only thing that pushes my PC now is gaming and most of the heat is from GPU. The heat from CPU is nowhere near the GPU, plus the bottom XE would drop the temperature even lower before the coolant reaches the GPU again.
 
Good idea. For multiple rads I would avoid setting up the hotter rad as intake. That would impact badly the other rad, if also intake, and the components inside the case. Feeding cool air, simply at room temperature to the case and exhausting warm/hot air, is the perfect scenario.
 
I have a rad in the front of my case blowing in and one on the roof also blowing in and the rear blowing out so far it's working great with a good set of custom filters.
 
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