Help me design airflow of this case.

tempoct · Post by **tempoct** » Sun May 14, 2006 8:40 pm

Hi,
There are 3 fans. PSU fan, HSF fan and one 60mm exhaust fan (SilenX, loud). I'm trying to improve airflow of the case. The temp is about 10c higher when I close the lid.
Condition: HSF 120mm Nexus Full speed, 60mm exhaust fan SilenX full speed.

Open case:
CPU idle: 29-30c System idle: 30-32c
CPU load: 42c System load:35-39c

Closed case:
CPU idle: 39c System idle: 41c
CPU load: 53c System load: 50c

CoolerMaster ATC-620 HTPC Case
MSI K8NGM2-FID, stock passive cooler on NB and SB
Athlon 64 3200+ Venice 1.15GHz - 2.3GHz with Zalman 7700AlCu (Nexus 120mm mod)
2 x 1GB Corsair XMS DDR400 + 2 x 1GB Corsair Value Select DDR400
eVGA GeForce6600 128MB, passively cooled by Thermaltake CL-G0003
160GB Seagate 7200.7 PATA in SmartDrive 2002 Aluminum, hard-mounted in 5.25 bay
BenQ DW1640 DVD-RW, hard-mounted in 5.25 bay
Seasonic S12-380
Still finding a good (fast) internal 3.5" multi card reader!

http://gallery127534.fotopic.net/p29241267.html

Any comment is appreciated.

BrianE · Post by **BrianE** » Mon May 15, 2006 2:24 pm

Yikes.

I don't know very much about airflow routing for HTPC cases, but some general ideas that would still be applicable are to:

1) Cut away as many fan/vent grilles as possible. That one next to the 60mm looks pretty restrictive, so cutting away all similar intake/exhaust holes (if cosmetically acceptable) would help breathing.

2) Minimise (useless) short-circuits between intakes and exhausts. The 60mm probably draws quite a bit of air from the vent right next to it, making it less effective. Some ducting or partitioning might help.

3) Open the PCI slots for more intake area.

4) See if you can fit larger fans such as 80mm ones, either internally or externally with some modification or cutting.

Two limitations I can see right away are the limited intake areas, and the 60mm fan which acts as the only exhaust other than the PSU. I'd try to find ways to mount a second fan (right next to it I suppose, and maybe slightly ducted around the 7700?), or even trying to fit one larger fan, mounted outside the case if I had to. Some people, including MikeC, has used external fans before.

tempoct · Post by **tempoct** » Mon May 15, 2006 3:36 pm

Thanks Brian.

1. Will do. I removed the 60mm fan now and the temp just went up a few degree. I will cut the vent free. Might put some mesh aluminum later. I believe it will act as intake.

2. This case is small. I try to duct the vent as CPU intake but the temp doesn't really improve that much. (as you can see the paper duct all over it!).

3. Will do. I might use on-board graphic instead.

4. I have to check on external 80mm. No way I can fit it internally.

It's possible to add two 80mm on both intakes with some mod. Do u think it will help? I'm not sure if the HSF is lacking of cool air or the case can't get the hot air out fast enough.

BrianE wrote:Yikes.

I don't know very much about airflow routing for HTPC cases, but some general ideas that would still be applicable are to:

1) Cut away as many fan/vent grilles as possible. That one next to the 60mm looks pretty restrictive, so cutting away all similar intake/exhaust holes (if cosmetically acceptable) would help breathing.

2) Minimise (useless) short-circuits between intakes and exhausts. The 60mm probably draws quite a bit of air from the vent right next to it, making it less effective. Some ducting or partitioning might help.

3) Open the PCI slots for more intake area.

4) See if you can fit larger fans such as 80mm ones, either internally or externally with some modification or cutting.

Two limitations I can see right away are the limited intake areas, and the 60mm fan which acts as the only exhaust other than the PSU. I'd try to find ways to mount a second fan (right next to it I suppose, and maybe slightly ducted around the 7700?), or even trying to fit one larger fan, mounted outside the case if I had to. Some people, including MikeC, has used external fans before.

HammerSandwich · Post by **HammerSandwich** » Mon May 15, 2006 6:18 pm

How about building a box around the Zalman? Seal the bottom half around the rear vent so the HSF blows case air through itself then out the rear. If the fan's there, might as well make use of it!

stromgald · Post by **stromgald** » Mon May 15, 2006 8:51 pm

You really need a bigger exhaust fan. If you look at my SFF setup in my sig, I'm running a similar setup except I have a smaller PSU with an 80 mm fan and a 120mm exhaust fan. Its relatively quiet until I start playing games.

For your system, I'd recommend replacing the 60mm with an 80mm exhaust somehow. Also try to seal off any rear vents that are acting as intakes. That vent next to the 60mm fan looks like a big culprit. Intake fans are unnecessary IMHO. You want a front to back airflow. That'll probably be best for most of your components. The only thing that might suffer is the CPU cooling since it'll be drawing warm air from the case, but it should be alright.

You also might want to consider replacing your graphics card cooling. On my 6600GT, I have a Zalman VF700 CU, which has a big 80mm fan. Its fairly quiet at 5V and cools the the card well. By opening the PCI slot next to the fan, it dropped temperatures across the board by about 2Â° because the PCI slot then acts as an exhaust (the VF700 uses a blow down fan).

justblair · Post by **justblair** » Mon May 15, 2006 10:10 pm

What about cutting a 120mm hole on the top of the case?

Install a duct from the top hole straight into the HSF, then slow it down.

Remove the 60mm fan.

I think what is happening is that the 60mm fan is robbing the HSF of the cool
air.

Other thing to try.

Block the other 60mm hole,

Reverse the 60mm fan.

This might help.

tempoct · Post by **tempoct** » Mon May 15, 2006 11:05 pm

I'm ditching the GeForce 6600 and using the on-board 6150. I'm not planning to play game with this one (but I do now

). That should give better airflow now.
Later on, I'll probably use one or two PCI slot in the future (one for capture card, another one for Wifi).
I'm considering slot fan and leave the 60mm off (also, I'm cutting the vent for more opening).

The top duct (CPU intake) is a good idea but I don't think it will work with this case. It has a big supporting bar at the top.

justblair · Post by **justblair** » Tue May 16, 2006 8:50 am

Doh, didn't register the top bar...

Could be moved I suppose, though just bypassing it with the duct would be easier. ie the entrance hole would be off centre. The duct would travel down and to the side.

but your idea sounds worth trying.

Slot coolers have a reputation for being loud though. Think Bluefront or one of the other regulars experimented with undervolting one. Cant remember the conclusion sorry.

You could always make your own "3 slot cooler" using a 120mm fan and some ducting. If you removed the graphics card as your suggesting this would give you plenty of space. An advantage of this would be the 120mm fan would be within the depths of the case and so further from your ears. The extra width would make it a less restrictive air path so quieter.

tempoct · Post by **tempoct** » Thu May 18, 2006 9:02 am

This works!
I also tried almost everything everyone mentioned here. However, this give me the best result. With the SilenX (LoudX) running in at low speed, the temp drop to 47 loaded. I think I could run dual exhaust fan at low speed that should give better result.

80mm intake fan in front of the PSU also give good result. Maybe I'll do that if I want to keep the video card.

HammerSandwich wrote:How about building a box around the Zalman? Seal the bottom half around the rear vent so the HSF blows case air through itself then out the rear. If the fan's there, might as well make use of it!

Thank you all for your contribution. Gimme lots of great idea.