Best Case Fan Mounting Strategy?

[GokuFurinji]

After installing an new Athlon XP1900+, mobo and Volcano 7 HSF in my Songcheer Extra wide case I wondered if my fan mounting strategy was correct!

I have the usual 80mm intake fan at the front blowing air into the case and an 80mm exhaust fan at the back blowing the air out! The PSU (although not AMD approved, my Enermax 350w arrives Monday) does have dual fans, one above the CPU and the usual exhaust one!

However on the lefthandside of the case (as you look from the front) I have cut two 80mm holes one above the other with mounting holes and installed two fans, the top fan blowing directly onto the HSF on the CPU and the bottom fan blowing the air back out!

I also stuck some small foam 'corners' on the corners of the fans I mounted on the side, a bit short of actualy encroaching on the blades before mounting, to act as a noise damper!

Does this sound OK or should I orient the fans differently, or remove the foam and use something else??

 

[camieabz]

I'm not sure that set up would give a good constant airflow. I would make both the side fans blow onto the CPU & put in a chimney or two on the top for exhaust.

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[Mavicator]

What you want to achieve is smooth and efficient air movement. One fan would have been enough on the CPU, but since you already have two, we can deal with that. Basically what you have right now is air entering the front and exiting the rear, which is desirable since the air behind a computer is usually hotter due to the typical placement of the tower under a desk.

The problem is, you've created a huge area of turbulence right smack in the middle of your air flow. The two fans over the motherboard will not allow for smooth airflow from the other fans or between each other. So the first order of business is to smooth that out. I would recommend facing both fans inward, blowing onto the CPU and video card. Now, with such a large volume of air being delivered to the center of the case you need an appropriate exhaust. The natural tendancy of all that air will be to split mostly left to right since the bottom of the case and the underside of the PSU will mostly prevent it from veering into the vertical plane. The air diverting toward the front of the case needs to be vented. Therefore I suggest turning that front fan to blow outward.

What we are left with is a case which vents all of its fresh air in directly onto the hot components, and is vented mostly out the back (remember you have 3 fans back there, not 1) and partly out the front. That should give more than adequate airflow to keep things cool.

Try to keep those IDE cables from blocking too much air from exiting the front. You can, as camieabz suggested put a vent in the top of the case. If you have a large case with lots of airspace, a top fan can work very well. But unless you use round IDE cables or get really creative with routing standard ones, the top fan won't be terribly efficient on a smaller case and may not be worth the cost and effort.

-- Ah sh*t! sys64738 --

 

[GokuFurinji]

Sound advice!

I checked the temp in the BIOS, the board I have is the Soltek SL-75DRV2 and the BIOS has two Temp readings that refer to the CPU:

Temp1 is 40°c
Temp2 is 55°c

but don't know how the CPU temp is measured?

I'll make the 2 side fans blow in and the 2 end fans blow out! The case has plenty of space inside, it measures 430mm High x 230mm Wide x 410mm Deep, so I'll see if the temp drops any further when I re-orient the fans!!

I've also been told about 'Acoustical foam' to line the case and reduce noise and also temp, so I'm going to ring a local foam supplier and check if they do sound proofing foam!!

I'm seriously thinking of getting round IDE/Floppy cables, but can you get round SCSI cables? Those are the 3 main causes of airflow blockage in my case! But like you say, careful re-routing should make a difference!

Give me something to play about with later on !

Thanks!

 

[Mavicator]

Not sure about round SCSI cables. Just make sure you get good ones so you don't run into data loss or corruption. And when you're done, your knees may get cold in the winter from that front fan! Heh!

-- Ah sh*t! sys64738 --

 

[GokuFurinji]

My room is usually too warm any way with all the heat from the case !

Swapped the fans around, seems a bit quieter now the temp is down and the Volcano HSF is not at full speed, boy was THAT noisy!! Just need some Acoustical foam and see if that drops the noise level more.

Now you may not like the next bit, in fact I'm sure you won't! I made my own 'round' IDE/Floppy/SCSI cables by neatly (and carefully) rolling and taping the existing cables! Not had a problem (so far) with data corruption, but I think I'd better make it 'temporary' till I get some 'proper' round cables! Shouldn't hurt for a while though should it?

I'll wait a few more hours and see what the temp is in BIOS.

Now to find some foam!

 

[Mavicator]

You can certainly make your own round cables. In fact, Ive seen web sites on how to do it. The problem is that standard ribbon cable isn't shielded very well so when you fold it on itself there is the possibility of the individual wires interfering with each other. Give it a shot though.

Glad the fans are working well now. It's probably quieter because the air is flowing more efficiently and the fans are working less hard. The sound foam probably won't help because most of the sound is exiting the fan holes. You can certainly try though. Another option is to buy really high-quality fans which run quieter.

-- Ah sh*t! sys64738 --

 

[camieabz]

I've used round IDE cables, but I haven't worked out if they result in slower movement of data. I use cable ties to keep the cables hard against the case.

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[GokuFurinji]

AH! EMF, I remember something similar with the old DC2120 Data Cartridges, the magnetism on one bit of tape could affect the data on the piece of tape above or below it on the spool, thereby corrupting it! Can't remember what the fancy name for it is, but my 'home made' cables seem fine, not had any silly problems crop up!

The fans I'm using at the mo' are 4 x CoolerMaster AF8-25IM-74, 80mm Ball Bearing variety!

With the two extra fans blowing on the HSF and MoBo it's definitely helped the air flow, the HSF is not screaming round at full speed now, that was an horrendous noise!!

The temp has not altered though, still 40/41°C, so it must have been the warm air inside not being exhausted efficiently that caused the ambient temp to rise and cause the HSF to rev harder, and my CD burner to throw up 'Power Calibration' errors due to excessive heat!!

Thanks Again!

 

[Mavicator]

Glad to be of help.

-- Ah sh*t! sys64738 --