Making a wind tunnel(update did it with results)

[Sniper82]

Well I ain't sure what you would call it. But was thinking about making a tunnel going from my CPU fan to a fan on my case. Was gonna set it up so the case fan would blow in cool air through the tunnel to the CPU fan. Keeping the CPU blowing cool air instead of constantly recycling the same warm air.

But I don't know if I should have the CPU fan sucking warm air to the case fan which will blow it out or have the case fan blowing cool air to the CPU to cool the heatsink. Which would most likely do more? Has anyone ever tried with? And what would be the best way to make one? I will be using Panaflo L1A's on both CPU and case.

 

[Excelsior]

Dude..
I was thinking of this exact same thing the other day. Sounded like a great idea to me. Having fresh air being blown onto the heatsink rather than the already warm stuff. If you get any more info, send me a pm. I figure this would be really easy to accomplish.

 

[Sniper82]

Did a little experiment. Took a card board box(5-6 inches long) and fitted it around a Panaflo L1A and taped it so no air could get out. Well I placed it over my 60mm CPU fan(completely over it) and held it there long enough to see how much the temp dropped. It dropped from 59c to 54c. I might have dropped lower but my hand got tired . Anyway I keep my side panel off so it was running 59c with it off.

This could be a good sign that it works. After I get something built with my side panel on I will give complete details.

 

[johncar]

Originally posted by: ^Sniper^
Well I ain't sure what you would call it. But was thinking about making a tunnel going from my CPU fan to a fan on my case. Was gonna set it up so the case fan would blow in cool air through the tunnel to the CPU fan. Keeping the CPU blowing cool air instead of constantly recycling the same warm air.

But I don't know if I should have the CPU fan sucking warm air to the case fan which will blow it out or have the case fan blowing cool air to the CPU to cool the heatsink. Which would most likely do more? Has anyone ever tried with? And what would be the best way to make one? I will be using Panaflo L1A's on both CPU and case.

It's called a "duct", we built our first one about 4 years ago, and commercial versions were on sale last year or two. But don't feel bad about coming late to the party, you have good instincts.

About 25 yrs ago we "invented" a new cleat (sailboat, for holding lines), made a model. Son said we should patent it, but we were just happy to have created the neat device, son kept the model, and we felt generally good. Last year son made a search and found earliest references to same idea about 100 yrs ago. Do you hear the sound of air escaping from a balloon??;-)

Anyway, best performance will have coolest room air flowing from case fan to hs fan. Might "consider" another "exhaust" case fan to help get rid of the increased total air flow...depends on how many exhaust fans you have now. Build duct out of any material, thin sheet aluminum, cardboard and tape, the pressure and temperature it sees will be very low...just be neat and don't let much air escape, so fit duct closely to perimeters of both fans.
Cardboard is good first choice in any case, as you can always use the final model as a pattern for duct from other material.

Keep thinking....
John C.

 

[Sniper82]

I know this is been out for a long while. Its just that no one ever really talks about it. I have seen it alot of times on web sites and stuff but didnt think anything about it. Was working on a newer Dell a few weeks ago that had something like this in it cooling a P4 1.8Ghz. I kind of hit me after that

 

[aircooled]

I've even seen it done much more passively. On my Old HP vecra servers (Pentium Pro's) they have a plastic duct from the Heatsink to a vented area at the back of the case..

Maybe a piece of PVC or ABS pipe that fits well around the HSF going straight out the side of the case, or use a 90 degree elbow and go out the back.

I guess you'll have to experiment a bit a take some temp readings along the way. Let us know how it goes!

 

[Sniper82]

Well I made another 80mm hole on my side panel right in front of my CPU fan. Made a tunnel out of cardboard and usps priority tape . It is over my 80mm Panaflo going straight to my thermaltake 60mm CPU fan(covering both fans completely).

Results before the tunnel:
57c idle
60-61c full load

After the home made crappy tunnel:
staying around 48-59c idle
assume it will go up to 53-54c load

Conclusion:
It dropped my temps about 10 celcius in the end. I think this is worth a try for anyone wanting to cool their system.

Cost:
Nothing . Use your imagination and it will cost you nothing as well. But cardboard and tape works wonders if its a straight shot to the CPU fan.

 

[TenEgg]

Can you show us some pics?

 

[Sniper82]

LOL I could if I tried but I'd rather not to be honest. Its not a pretty sight but I wasnt looking to spend any money to try something that might not work. Now that I know it works I might be willing to look into buying something that looks a bit nicer.

Whatever you use just make sure it will be able to fit over a 80mm fan and your there. Use some tape if you have to, to get it to stay on the side of the panel. Just carefully put the panel back on watching the end that goes over the CPU fan making sure it is clearing everything.

 

[blade2]

i was thinkin about using a fan duct aswell - are you running HSF and duct fan blowing???

have you any other case fans running for circulation? just now ive got, well an assortment of fans...
1 3000rpm fan that was originally the HSF fan, quite silent, made from metal - Aluminium?
2 4000rpm fans - damn noisy, moves a fair bit of air mind..
and a near silent fan that i pulled out of my old PSU, damn silent, moves average amount of air...


so i moved fans around and currently have the 3000rpm suckin air in at the bottom front of the case with a sort of duct, well an empty box of pringles tilted so it pushes air towards the CPU

CPU/HS has a 4000rpm strapped to it suckin air onto it...
exhaust fan is the ex-PSU fan..

temps are roughly 33/45C case/CPU