Odd airflow question.

[Sauvage]

To give you an idea as to what I am doing, without giving away too much (its a one of a kind custom mod I am designing) I want to build the case out of plexi. No case fans involved and no H2O, but instead maybe a nice industrial-type 6" fan forcing air into ductwork that would be divided up as it entered the case so that it would blow across all the components evenly. Then have a similar set-up on the opposite side of the case that would collect the air and funnel it into an exhaust port.

So has anyone here made, or know of a link to someone who has made, a sealed computer case like this? Maybe even something similar, or have an idea what kind of airflow I would need?

 

[pip_seeker]

best way would be a pull design.

This would relate to having a good size fan in the back of the pc. Then you connect the duct work to it with an opening in the front.

The fan would blow outwards... thus pulling air in through the front.

However, air movement by other fans in the system [IE cpu fan, some video cards] could mess this air flow up... unless of course you use a silent cpu heatsink and video card that dispels heat out the back.

You would definitely want a temp probe in there so you could monitor the temp of it. Don't forget about cooling those hard drives either.

 

[leo2kp]

I agree...negative pressure would be best to exhaust the air. Positive pressure will most likely create pockets of hot air.

 

[Aragorn]

I believe the OP was speaking of having an in and an out fan. If this is the case is it a good way to go? Does the pull fan need to be stronger than the push fan? Is it a bad idea all around to use both and that being why your responses were what they were?

 

[rallyimprezive]

Wind Tunnel Case?

 

[mi1ez]

If it's a sealed system, then they would surelywould to be equal, although I think smaller fans would help to split the airflow evenly to the different comopents. Best bet is to leave fans on CPU but fit a side blowing HSF. For the graphics cards, make sure you have a rear exiting cooler and just stick the pipe over the whole where the fan is.

No, I don't know anyone who's done this.

 

[rallyimprezive]

oh I get it now.

You may need to build diffusers that will help split the flow. Conversly, if the individual ducts have the right amount of back-pressure, it will prevent any one duct from getting all the flow.

Its like a mini forced air a/c!

 

[gwolfman]

interesting, share some pics!!!

 

[mi1ez]

If you used individual fans inside the ducts after the split, rather than the diffuser, it wouldn't matter if you got it wrong, it would give a lot of room to experiment with rather than relying on one calculation (which would need to tak into account the curvature just before the split as well as the size of the pipes it's splitting off into)

 

[leo2kp]

I believe he meant a single 6" fan, not an intake AND exhaust fan.

For a single-fan configuration with ductwork that would direct airflow to simulate many fans, I believe using it as an exhaust fan would be ideal as pushing air in would create hot pockets of air, while negative pressure would suck air in through the vents and more hot air is being sucked out. You will have more hot air in the case with an intake setup vs. an exhaust setup. Creating ductwork would be difficult as you would have to create parts that cover all of the primary heatsinks, but it would be easier to create an intake setup. You can find setups like this in pre-built machines from Dell where the exhaust fan has a "duct" around the CPU to suck the air through the heatsink. The fan acts as both intake and exhaust that way and cuts down on noise.

Personally, the best solution would be to have two low-noise, low RPM fans that would equal the airflow of an industrial 6" fan and use one for intake and one for exhaust, as most typical PCs have today.

 

[mi1ez]

The only reason I was suggesting using smaller fans was to regulate the airflow between the different components once the duct has been divided- I'd want far more air going to my CPU than my HDDs!

 

[chunkymonster]

I've not seen or heard of someone using ductwork combined with a push/pull airflow system. Certainly sounds like an interesting idea.

However, I did see a custom mod once where a guy used a 2 - 18" fans in a push/pull in a custom created case that was rectangluar in shape, the fans on the ends of the rectangle, and the components arranged inside in a way that allowed for complete ariflow over all parts. I believe he also used one of those passive Zalman flower type cpu coolers (CNSP-6000Cu), and a passive heatpipe gpu cooler. The layout of this guys mod looked something like the below image.