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Cooling Conundrum

Joined
Mar 11, 2009
Messages
1,778 (0.30/day)
Location
Little Rock, AR
System Name Gamer
Processor AMD Ryzen 3700x
Motherboard AsRock B550 Phantom Gaming ITX/AX
Memory 32GB
Video Card(s) ASRock Radeon RX 6800 XT Phantom Gaming D
Case Phanteks Eclipse P200A D-RGB
Power Supply 800w CM
Mouse Corsair M65 Pro
Software Windows 10 Pro
I just bought a corsair H105 extreme performance liquid AIO secondhand. It's a 240mm rad. I want to fit it in a Cooler Master HAF 912.

The problem is, the rad mount is in the top of the case, and it interferes with the rear exhaust fan. I can't seem to use both at the same time. So what should I do? I have one fan up front, potential of two, currently pulling in, as the previous configuration was all air, one intake front, one exhaust back, two exhaust top.

Put the rad up top, fans pushing out? Problem with that is, case air would be cooling the CPU. I'd rather have fresh air from outside if possible, as I have an EVGA graphics card that doesn't exhaust out of the case, so case air will be potentially hot.

Rad up top pulling air in? Since I won't be able to use the rear exhaust, the only option for exhaust is the two front fans. I'd rather not exhaust out the front for obvious reasons, but I guess if that's all I can do, it's all I can do.

There is also a side vent that can have a fan put in. So maybe... rad up top intake, intake up front, exhaust out the side? I don't know if the side one will be effective enough, since it's lower. But maybe I'm overestimating that effect.

Or would an intake on the side, exhaust out the rad up top work better?

What do you think? What's best? Are there other options I'm overlooking?

Thanks in advance!
 
There is also a side vent that can have a fan put in. So maybe... rad up top intake, intake up front, exhaust out the side? I don't know if the side one will be effective enough, since it's lower. But maybe I'm overestimating that effect.
The effect of convection is negligible over the effect of fans. So fans making air move upwards or downwards are equally effective, convection plays a part only when there are no fans moving.
The only no-no is having warm air from inside the case blowing into your rad, because this way you are seriously affecting its performance. The other 2 options are both feasible, front output, or lateral output.
If you do front output, you will end up with a slight negative pressure, if you do lateral output, you will end up with a positive pressure setup. I'd say that the front output sounds like the highest performance, because the negative pressure will improve the performance of the rad. But you could start with the setup that you like most, test, and if you find that you still need the few extra degrees, move to the front output.
 
Actually, I just started trying to test fit things, and there's not even enough clearance over the mobo for the rad to be mounted up top lol. It's too thick. Maybe I can do some Frankenstein solution with the fans mounted external to the case lol.
 
Actually, I just started trying to test fit things, and there's not even enough clearance over the mobo for the rad to be mounted up top lol. It's too thick. Maybe I can do some Frankenstein solution with the fans mounted external to the case lol.
Maybe you can do this at the front? Fans outside the case is not that good for fingers, cats, children etc.
Like this:

Also, if you can use the lateral intake as an intake, it could be very good for the graphics card.
 
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Maybe you can do this at the front? Fans outside the case is not that good for fingers, cats, children etc.
Wont fit up front either, unfortunately. I'm thinking maybe fan grill->fan->case top->rad, in a big sandwich.

If I don't just decide this is a bust lol. I'll probably just put it in something else at some point.
 
Actually, I just started trying to test fit things, and there's not even enough clearance over the mobo for the rad to be mounted up top lol. It's too thick. Maybe I can do some Frankenstein solution with the fans mounted external to the case lol.
Hi,
They do make grills for exterior fan mounting.
 
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Chassis specs show just the rear is capable of holding a radiator. External is the best option unless you want to drill out the rivets for the drive bays and try it up front.
 
Yea that's the sort of thing I had in mine, If I decide to do this.
Hi,
I did a second floor on my cases to hold the radiators :)
Apex lights.jpgx299 and x99 open filter tops.jpg
 
Chassis specs show just the rear is capable of holding a radiator. External is the best option unless you want to drill out the rivets for the drive bays and try it up front.

Yea I guess I just assumed the top was able to hold a rad/fans. I might consider taking out the drive bays. I think I can probably fit all my drives in 5 inch adapters in the cd drive bays. Might be the direction I go.

Hi,
I did a second floor on my cases to hold the radiators :)
View attachment 162121View attachment 162123
I'd def just mount the rad externally if it was a custom solution. But I don't want to break open the AIO to route the tubing into the case.



Update: Well the rad even without the fans won't clear the shroud around the I/O hole. So If I want it to fit in this case, I'm doing case modifications either way. Probably won't bother unless I get the itch to take it out the workshop. Thanks for the advice everyone!
 
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Yea I guess I just assumed the top was able to hold a rad/fans. I might consider taking out the drive bays. I think I can probably fit all my drives in 5 inch adapters in the cd drive bays. Might be the direction I go.


I'd def just mount the rad externally if it was a custom solution. But I don't want to break open the AIO to route the tubing into the case.
Hi,
All it takes is a hole large enough for the water block for a clc/ aio :D
x99-new fluid-screen-temp-sensor.jpg
 
Hi,
All it takes is a hole large enough for the water block for a clc/ aio :D
View attachment 162136

Yea maybe I'll just poke a hole in the top and run it through. Shame, cause it has holes/grommets for external rads already. Or I'll just buy a new case lol.
 
Hi,
Yeah mods were my choice cases seem all the same to me just cost a lot more :-)
 
I'm no stranger to DIY lol. I've been hacking apart cases for nearly 20 years. I'm especially proud of my open bench that I hacked apart a case to make lol. I just don't know if it's worth the work for a 4 degree temp drop or the like lol.
 
Ok so I googled haf912 with 240 aio. First hit says the option is to put the rad at the top, fans above the chassis, with fan grills over them. Seems the easiest option by far!
 
Ok so I googled haf912 with 240 aio. First hit says the option is to put the rad at the top, fans above the chassis, with fan grills over them. Seems the easiest option by far!
That does seem to be the best option. However, I still have to cut out about 5mm of the metal shroud that sits around the I/O shield in order to get the rad to fit internally, even by itself. It's just SO slightly too thick, and won't slide in. So that means disassembling the whole thing. I might do it eventually, but I figured this was gonna be a 15 minute job for a slight temp decrease, not a whole ordeal lol.
 
The perception that you somehow need to have both intake fans and exhaust fans has no base in the science the thermodynamics or engineering design. It's not like air pumped into the case will stay in there until a fan sucks it out.

When you turn on an attic fan in ya house ... where is the intake fan ?
When you turn on an ya kitchen exhaust fan ... where is the intake fan ?
When you drive your car, your intake fan pulls air thru the radiator .... where is the exhaust fan ?
Of you don't have AC, and want too cool down your bedroom, you do that by putting a fan in one window and opening another.

Whether a PC fan is an intake or exhaust fan, depends on one thing ... it's placement.

You are following the 2nd law of water cooling ... Rad fans always blow in ... if not the 1st ... "never mix metals in a loop".

If you have 4 fans blowing into the case.... air will be forced out thru the fan mounts due to the internal pressure provided by the fans. The original 912 didnt have vented flot covers .. if yours are not slotted / vented, then these are readily available


The rear and side fan mounts alomg with the vented slot covers will provide more than enough area for air to escape the case.
 
One sec.....let me find the link again and see how they got passed that issue.


Different model, you would need to compare lengths I guess. Quite possible your rad is a touch longer.

Just checked, the corsair is shorter than the one used in the link, by like 1.5mm.

Have you tried installing with the tubes at either side? It may only go in one way since one header on the radiator is bigger than the other.
 
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I'm no stranger to DIY lol. I've been hacking apart cases for nearly 20 years. I'm especially proud of my open bench that I hacked apart a case to make lol. I just don't know if it's worth the work for a 4 degree temp drop or the like lol.
Hi,
Think of it this way
Push/ pull fans but yeah for an clc/ aio you can go either way on that one
I'm using 280GTX rads push/ pull on top my cases so it was not much of a fight on if it was worth it or not seeing not many cases would allow that without blocking the top of the mother board a bunch.
 
The perception that you somehow need to have both intake fans and exhaust fans has no base in the science the thermodynamics or engineering design. It's not like air pumped into the case will stay in there until a fan sucks it out.

When you turn on an attic fan in ya house ... where is the intake fan ?
When you turn on an ya kitchen exhaust fan ... where is the intake fan ?
When you drive your car, your intake fan pulls air thru the radiator .... where is the exhaust fan ?
Of you don't have AC, and want too cool down your bedroom, you do that by putting a fan in one window and opening another.

Whether a PC fan is an intake or exhaust fan, depends on one thing ... it's placement.

You are following the 2nd law of water cooling ... Rad fans always blow in ... if not the 1st ... "never mix metals in a loop".

If you have 4 fans blowing into the case.... air will be forced out thru the fan mounts due to the internal pressure provided by the fans. The original 912 didnt have vented flot covers .. if yours are not slotted / vented, then these are readily available


The rear and side fan mounts alomg with the vented slot covers will provide more than enough area for air to escape the case.

I was an HVAC tech for years, I'm aware of how positive pressure and static pressure work. I was more referring to the fact that I'd like to get the hot air being pulled into the case from the rad *out* of the case before it reaches my graphics card and affects the temp on that/other components. Positive pressure works fine, but only if you're not actively pulling hot air into the case (which doesn't happen if you're using an air cooler on the CPU).


One sec.....let me find the link again and see how they got passed that issue.


Different model, you would need to compare lengths I guess. Quite possible your rad is a touch longer.

Yea it's not the length, it's the thickness of the rad. In that first pic, you can see a little bit of the metal shroud below the rear fan. That shroud goes almost all the way up to the top, and there's just a couple hair's thickness too much to allow the rad to go in.
 
I was an HVAC tech for years, I'm aware of positive pressure and static pressure work. I was more referring to the fact that I'd like to get the hot air being pulled into the case from the rad *out* of the case before it reaches my graphics card and affects the temp on that/other components. Positive pressure works fine, but only if you're not actively pulling hot air into the case (which doesn't happen if you're using an air cooler on the CPU).




Yea it's not the length, it's the thickness of the rad. In that first pic, you can see a little bit of the metal shroud below the rear fan. That shroud goes almost all the way up to the top, and there's just a couple hair's thickness too much to allow the rad to go in.

Got it, my bad!
 
I have one more thought, but it kills the case for anything after.....

You could cut a section if the fan hole mesh at the top, big enough to drop the head unit in, then put the rad and fans on top of the case.

Other than that, maybe sell the 105 and look a thinner AIO on the cheap. Let me look at something real fast..... shit, the Arctic solutions are just as thick :(
 
Hi,
I've seen a significant flow difference in single fan verses push/ pull fan setup.
Plenty of smoke tests around showing a large difference.
 
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