DIY Kama Bay push-pull fan tube

[Syzygies]

The following mod adapts a Scythe Kama Bay, used with three 5.25" bays as shown here, to use two fans and a tube.

I used a 5.5" length of 5" diameter acrylic tube cut for me at TAP Plastics.

Kama Bay fan tube

Interior view

Exterior view

My theory is that the tube couples the fans, and reduces turbulence, increasing their efficiency. I found that my Q6600 ran 5 C cooler with my case open; this is my response, giving me a five fan straight shot through the case to feed my TRUE ambient temperature air.

Assemby notes: It wasn't necessary to Dremel the bottom panel off the Kama Bay; I was experimenting and wanted better access. I replaced the #4 screws and used lock nuts. I used cable ties as scaffolding, then hot glue gun attached the fans to the tube.

Having the filter on the input end makes it harder to get at for cleaning, and caused a strange noise in the front fan. Moving the filter to the exhaust end solved both these problems.

A little silicon foot under the tube would provide extra strain relief; my tube is now cantilevered, but seems to be doing fine.

A silent computing enthusiast might not be entirely happy with the acoustics. Not exactly blowing on a bottle, but the tube does reinforce a particular fan tone. I can easily live with this, for better air cooling performance.

 

[Tim]

Pretty neat. I have a kama bay I'm not using... It might find its way into my next build, not sure yet.

 

[SolMiester]

Nice, however I would of continued the pipe to within 5-10mm of each fan on the cooler.....

 

[Syzygies]

Originally posted by: SolMiester
Nice, however I would of continued the pipe to within 5-10mm of each fan on the cooler.....

The pipe would need a cutout for the memory sticks, and I'd need a power cable extension, a dodgy idea when some feel modular supplies are already a bad idea. A "half pipe" extension might improve ambient air delivery to the TRUE, coming after the second tube fan.

 

[ShockwaveVT]

nice work

Have you done any testing to see whether or not having all those fans makes a difference? Not sure that 2 fans so close together with such an unrestricted, enclosed path would make any appreciable difference in airflow vs having a single fan at the exhaust end of the tube.

 

[Syzygies]

Originally posted by: ShockwaveVT
Have you done any testing to see whether or not having all those fans makes a difference?

Martin's Liquid Lab has some interesting discussions on fans: Fan Testing

There's a old saying in the car sales business, "People buy horsepower, but they drive torque."

For fans, "People buy cfm, but they drive static pressure."

He summarizes one table with

This would indicate that stacking of 25mm fans is a good means to adding static pressure, and also that you're better off with some lower speed 38mm fans instead of 25mm types.

It takes static pressure to pull air through a filter. One could go filterless. I don't see how the second fan could hurt performance, and push/pull helps with my TRUE, so I thought I'd extend the principle.

I did confirm I had a problem before: My cores ran cooler with the case open.

 

[ShockwaveVT]

Interesting link, I never spent much time thinking about fan pressure, I figured it would be correlated to CFM but that is not the case. You definitely want enough pressure to maintain steady, quick airflow through the filter & through the fins of your heat sink.

I would still be interested to see temps before & after you set up the fan tube.

 

[Syzygies]

Originally posted by: ShockwaveVT
I would still be interested to see temps before & after you set up the fan tube.

I'm away from this machine for another week, and my first concern when I get back is to get Core 0 temps back in line with cores 1, 2, 3, which improved significantly after lapping. But then it will be easy to do a controlled test back and forth. I'm also curious; I'll report then.

 

[RallyMaster]

This thread made me want to take out my original Cooler Master 4-in-3 device module and throwing it in the Centurion 590...

 

[OblivionLord]

Old thread but i thought i would throw in some words.

I found it more pleasing to the ear to not use fan filters and to also drill out the honeycomb grills. This is my case...
http://community.webshots.com/...9822050044675130KHQNlj

http://good-times.webshots.com/photo/2941923830044675130egvNjo

There is no change from temps running the system with the side panels open or closed. Im running a 4.0 quad as well.

Only reason why i have a filter on the bottom fan is because I run that all the the time on low to cool the hdd. The other front fans are always off by control of the fan controller in the 3.5 bay. I keep the front door closed unless I game which is the only time I open it to then turn the front fans on but only 25% up. I clean the inside of my case once every month or 2 with can air.

25% is all I need for the front fans to be on just to keep the case cool. The rear fans I keep on at 25% 24/7. If I shut those off then it really gets hot because of extreme lack of circulation since the CPU would be the only fan running on the top compartment.

Keep in mind that when gaming, the cpu and gpu are never at 100% load the whole time compared to synthetic means like Prime95 for the cpu or Furmark for the gpu. This is the reason why I'm able to get away with the low fan speed and the fact of less restriction by removing the grill. However when I do use the 2 above synthetic stress programs, I ran both the front and rear fans at 50% just to maintain the case temp at load to match it's idle temp.

Flex F 120mm fans is what I use for the front 2 fans. The 2 rear fans are the stock Antec which I have set on it's built in controller to medium.

If you put your hand behind the bay where the Karma Bay fan is then you will feel a turbulence of air where the 5.25 bay acts as a duct in itself. Yes it isn't as powerful as having straight inducted air from using 2 fans but, in my case with all the above mentioned, it just isn't necessary for now.

However if in the future when there are components that run much hotter then what I currently have then I will diffidently keep this mod in consideration since it does serve it's purpose. For now I don't think that even a GTX295 will increase my case temps all that much more than what it currently is unless I do away with its cooler that expels it's hot air out the rear just like how my current videocard card is doing. Yes it is a dual pcb which also accounts for 2 GPU's but, the air is still contained and expelled out the rear none the less. It may not completely contain all the heat but, it does a very efficient job at it.