cpu duct wut? wut? wut?

[shauns]

I want THIS (http://www.overclockers.com/tips635/) but i dont know what he used for the duct "high heat automotive manifold duct" where the heck can i get this stuff? and has anybody done it? it looks like it would work and very effective.
and..how hard would this be on a swiftech MCX-478 (the one he did was on a round HSF and the MCX is on a square and advice?

[cyber mouse45]

I came up with the same idea a few days ago, though I’d never seen it done before. But since heat rises I’m going to have the hose go out through the top, not the back. I’m going to go to Lowe’s in a day or so to look at air ducts and hoses. Hopefully I can find something there. If not, I’ll try Pep Boys or Track Auto. As far as attaching the round hose to the square fan, I’m not 100% sure on what I'm going to do yet. I might go with electrical tape or something. I can let you know if I come up with any more ideas if you want. I still have a few more days before my case and stuff arrives. :D

[shauns]

Originally posted by cyber mouse45
I came up with the same idea a few days ago, though I’d never seen it done before. But since heat rises I’m going to have the hose go out through the top, not the back. I’m going to go to Lowe’s in a day or so to look at air ducts and hoses. Hopefully I can find something there. If not, I’ll try Pep Boys or Track Auto. As far as attaching the round hose to the square fan, I’m not 100% sure on what I'm going to do yet. I might go with electrical tape or something. I can let you know if I come up with any more ideas if you want. I still have a few more days before my case and stuff arrives. :D

http://www.overclockers.com/tips635/
this is where i got the idea

[juliendogg]

woah! that's a sweet setup. let me know how you guys make out trying to use it. that duct he's using is a standard part to move hot air from the exhaust manifold up to the air cleaner or intake to provide warmer air to the carb in cold conditions. they'll have them on a shelf somewhere at any auto shop. they are also relatively easy to bend and i think you could even crease the end into a square to go over a swifty or alpha!!

[cyber mouse45]

Originally posted by juliendogg
woah! that's a sweet setup. let me know how you guys make out trying to use it.

Sure thing. I'll see if I can get some pics on here when I get things going. The case should get here in 2 or 3 days. :D

[Hoot]

Just a technical note. Hose like that, with the corrugated surface has a fairly high resistance to airflow, despite its diameter. The very corrugation that lends to its flexibility acts as "speed bumps" for the air and causes a lot of turbulence inside the hose. If you use it, put a fan at the entrance blowing into it. Relying upon just the draw from whatever HSF you are using may prove disappointing.

Hoot

[cyber mouse45]

Hmmm.. good point. Do you have any thoughts on what I could use??? There is some smooth hose under the hood of my truck, but I think that kind of stuff would be to stiff to use. What about PVC pipe?? An elbow then a straight piece right out the top?? :confused:

[juliendogg]

i think pvc would work well, but the pipe shown in the picture in the first post would probably be okay if you could keep it short enough. other than that maybe smooth rubber hose. like a radiator hose. you can go into some parts stores and look through their stock of them to find one that already had bends close to what you would need. only i don't know if the diameter would be large enough....

hmmmm.... keep thinkin and i will too

[Myself and I]

So would you see a big difference if you were to make a tube go from your cpu fan to the top of the case?
I mean just imagaine it like in the picture if you could suck all the hot air off the heatsink and then exaust it through the top
would that work?

[shauns]

the whole point to this was to get COLD air from the outside to be sucked into to the case via a basicly cold air intake (if your into cars) to the case instead of the other way around. cold air on CPU=GOOD =)

[cyber mouse45]

Here’s something I came up with. How about two hoses?? One going to the cpu, and one going away from it. Look at the pic if I can get one on here. Blue dots is cold air coming in, and red dots is hot air going out. This is what I think I might do to mine. If anyone has any other ideas, I’m all ears. :D

[Myself and I]

hey thats what i would think
but some people are saying bring in cold air is better

[diehrd]

I caution against metel cause my mind says you do not want to ground the heat sink to the case as it sits upon the processor core.{This might be silly thinking but who knows}

I have run ducts for a while now on my dual AMD box with great results.It lowered temps by 8c.From 47c max load to 39c Using 2 Sk6 and 2 delta 38cfm screamers.

My next mod to it was Installing 2 x 30cfm fans, temps went to a max of 41c and noise dropped by 50%.I can actualy here my hard drive spin up again and boy it is loud LMAO.

The ducts are PVC pipe reducers.3.75 to 3.0 inches.[Home Depot}
The ducts slide easly over heat sink fan and are bigger around than the sink Allowing room for the case side to slide that little it needs to close tightly.

The ducts sit over fans but only about 2/3 of the way down the fan.This ensures intake without redrawing the hot air pushed off the heatsink back into the air flow supplied by the ducts.

The ducts are held on by L brackets that are in turn held on by grill screws and nuts on the outer side of case.

I also have 2 80mm intake fans below the ducts these fans do 2 things thay circulate cool air directly to main board and help push the warmer heat sink air away from the heatsinks.

Above I use 4x80mm exhaust 3 on case and 1 on p/s.balancing my supply of air and my exhaust of air,{I have duals so you may need only half this much}

To locate heatsink on case side is rather easy all you need to do is measure right and left to center of fan.top and bottom of where door ends on case to center of fan and then transfer these measurements to case side.I used a 3 inch drill mounted metal hole cutter.{HomeDepot}

Grills from Comp USA as well as my case fans.Here is a pic.

[cyber mouse45]

Here's the pic:

[cyber mouse45]

Here's the side:

[cyber mouse45]

What do you think???

[nihili]

For what it's worth.

4" vinyl dryer hose fits nicely over a square 80mm fan. The vinyl is just stretchy enough to conform pretty well to the shape. 3" hose will fit a 60mm fan. Both sizes of hose, as well as size converters should you need them, are dirt cheap at your local hardware store.

Hoot's point about turbulence is exactly right. I find the duct does much better with identical fans at each end to overcome the static pressure that a corrugated duct has. Of course a rigic smooth duct would be preferable. But it would also be much more expensive and harder to make. A dryer hose duct will get you started for less than 5 bucks while you learn and experiment on your way to designing th eperfect duct.

nihili

[Trieber]

The duct is a good idea. Provided the air flow is uniform. About the idea of having an intake and output.. well that can get messy.. you could have air in on one side, and air out on the other, but with a fan on either side, I would assume you lose some efficiency. With air coming in from the sides and being pulled out so fast, I don't think the air would be able to cool the HS. It's something to experiment with though.

But I think just a fan at the top of your case would be enough to vent the hot air. Remember, heat rises and a fan at the top sucks out the hot air that rises.. fundamentals guys..

Also, the idea about a fan blowing air into the pipe, and a fan at the sink pulling it out sounds good, someone might have to try this with one or the other.. Hmm, can't concentrate now...

[Trieber]

You guys posted while I was writing.. about your drawing, the fans at the front of the case should either be intake or outtake, not both. Why have 2 fans fight each other? Also, the fans at the bottom should be raised so they blow freshair and not fight the case bottom. As for the vent with the window.. I would suggest a fan to blow out, or lose that and just rely on the exhaust fan at the top..

And btw, is that a napkin?

-I laughed my ass off at that, so funny-

[cyber mouse45]

Now that you mention it, it does look like a napkin. lol It’s just a really crappy scan that’s all. As far as the fans in the front, do you think it would be better for more cold air to come in or hot out??

[nihili]

Originally posted by cyber mouse45
Now that you mention it, it does look like a napkin. lol It’s just a really crappy scan that’s all. As far as the fans in the front, do you think it would be better for more cold air to come in or hot out??

The general wisdom seems to be that the in and out should be balanced. The main thing is that you need to be aware of the details of air flow through your system. You want to avoid any areas of stagnant air as they will greatly increase the heat in your system. Unfortunately that's something you have to do on your own system as no two systems are exactly alike.

nihili

[cyber mouse45]

Originally posted by nihili


The general wisdom seems to be that the in and out should be balanced. The main thing is that you need to be aware of the details of air flow through your system. You want to avoid any areas of stagnant air as they will greatly increase the heat in your system. Unfortunately that's something you have to do on your own system as no two systems are exactly alike.

nihili

Thanks!! :D

[Trieber]

This is a simple rule of thumb, lower fans should blow in and upper fans should exhaust...

The reason for this is simple, cold air is denser and sinks, so lower fans should blow this cooler air in. Nhili is right about balancing it out. You want to try and keep air moving throughout the whole thing. If you mount a fan at the bottom, space them so air is moving uniformly, not just all on one side, and if you do this, have all bottom fans blow up, alll top fans exhaust, all front in take, and all back exhaust.. Don't try and make the fans fight over each other...

[cyber mouse45]

Hey guys, what about something like this. (this is a pic of the same case I’m getting) What if you had a hose that blew up cold air up from the bottom and stopped about an inch or two from the cpu, and another hose about an inch or two from the top of the chip sucking all the hot air out through the top of the case??? The black squares are fans, and the gray fog is the air hose. Think this is any good?????

[vodka314]

That looks insane.

[diehrd]

LOL vodka have you been sipping on your name ???

[cyber mouse45]

Originally posted by diehrd
LOL vodka have you been sipping on your name ???

LOL that's funny! :D

[Pepsi]

Cyber Mouse45
I have te same case as you. The lower bay is what they call the HD bay I took mine and put a 110 volt 36 cfm fan in there (blowing in) and it works really well. The HD's I moved up to the top right over the A drive bay. I put the switch for it in the A drive bay facia cover that I as not using, it looks really slick.
Stay Cool
Pepsi:cool:

[cyber mouse45]

Could you post a pic of it Pepsi??? :)

[UserName]

For duct material i'd use cardboard.

Smoothe and easy to work with.

Perhaps card stock instead of the coragated stuff would work better, but both are good.

No risk of fire, electrical damage or melting.

P.S. Hot air rises with very, very little strength. You are much better to blow coold air over your CPU and motherboard and hot out the front and/or top of your machine.

[Darrenct]

Here's what I'd love to try...

I have an Alpha pal8045 HS, so it is designed to have the fan suck off of the heatsink. I'd use a duct like Diehrd's to exhaust the hot air out in to the open instead of in to my case.
Then I want to build some kind of housing around just Heatsink, and have cold air blowing in to this housing.
Of course, my $15 mid-tower case doesn't give me much room to try all that fun stuff.

I like the cardboard Idea, it's easy to work with, my only issue is that I have a window, and cardboard looks so Ghetto... I suppose if you painted it... I don't know, the one in the original post on this thread looks so professional.

Here's a rough idea of what I mean... Of course, you'd need as much intake as exhaust.

[shauns]

has anybody accually DONE this? what was shown in the accually images?
http://www.overclockers.com/tips635/ducting2.jpg

i would love to see your images....

[nihili]

Originally posted by shauns
has anybody accually DONE this? what was shown in the accually images?
http://www.overclockers.com/tips635/ducting2.jpg

i would love to see your images....

It depends on what you mean by "this". Lots of us have ducts. I have a duct from my cpu to the rear of the case using vinyl dryer duct. It looks a bit different than the one you show because I have a socket rather than a slot cpu. So it doesn't have the big bend that one does.

Here's a picture from when I first put it in. The black thing converts from 3" hose to 4" hose.

nihili

[shauns]

ya..i have a socket too...so i guess it would be alittle harder to do w/ that and make it look "presentable" not saying yours doesnt, but his just looks alot neater

[nihili]

Originally posted by shauns
ya..i have a socket too...so i guess it would be alittle harder to do w/ that and make it look "presentable" not saying yours doesnt, but his just looks alot neater

Remember, a lot of what makes his look spiffy is the fact that there aren't any visible cords hanging around. Also he's using shiny automotive hose rather than cheapo dryer duct. You can do exactly what he has but without the extra curve pretty easily. The extra curve actually will make the duct perform worse. But it you like the looks enough, find a heatsink with a fan on the side rather than the top.

nihili

[drunkmonkey]

Originally posted by cyber mouse45
I came up with the same idea a few days ago, though I’d never seen it done before. But since heat rises I’m going to have the hose go out through the top, not the back
You've got it backwards, you use the ducting to get a cool airflow onto your processor. You suck air INTO the comp. through the ductin, so if you have a hot case temp:mad: you can still have a cool processor. I saw a comp. with ducting and his processor was coooler then the case.

I'm soon puttting a ducted 120V case fan w/ 300cfm onto my processor wahahahaha! It'll be very :cool:

[Captain Slug]

I did this a year ago by using a Vinyl Dryer Hose and 3 inline 80mm fans (bolted together to increase forward air pressure needed to push air into the tube).
The noise level was much lower than I had expected and the cooling efficiency was as anticipated. My CPU temp dropped 9 degrees f and my case temp dropped 6 degrees f.

Vinyl Dryer hose isn't optimal because of hold many internal flow obstructions there are from folds and such but it is 85mm in diameter and strapped onto my fans and HSF easily.

In my opinion a blowhole on the side of the case just above the HSF would be more effective.

Here's a pic...
http://www.gamesig.com/images/r2k/box-milleniumPlexi.jpg

[nihili]

Originally posted by drunkmonkey

You've got it backwards, you use the ducting to get a cool airflow onto your processor. You suck air INTO the comp. through the ductin, so if you have a hot case temp:mad: you can still have a cool processor. I saw a comp. with ducting and his processor was coooler then the case.

I'm soon puttting a ducted 120V case fan w/ 300cfm onto my processor wahahahaha! It'll be very :cool:

Actually it can be done either way. I have my duct exhausting. The result is that my case temp seldom rises much above ambient. I originally built my duct to use with a Thermoengine. With that setup I actually got better results using the duct as an exhaust. I haven't tried the duct as an intake since switching to an 8045, so I can't verify which direction works best with my current setup.

As for the 300cfm fan on to your cpu, you should remember that the law of diminishing returns applies to cfm over a heatsink too. After a certain point (which depends on the heatsink) increasing the cfm provides very little benefit. Give it a shot and see what happens, but you might be better off using the 300cfm as a case fan.

nihili

[donny_paycheck]

For high resistance tubing such as dryer hose, a squirrel cage blower might be your best bet for high volume airflow. They generate omderate pressure, much more than a tubeaxial fan does, and with pretty good volumes too. They're a little more expensive but you'd only need one. A 12 volt blower from a vehicle's HVAC system might work well, or you can get them from places like Grainger (http://www.grainger.com/Grainger/searchcategory.jsp?xi=xi&category=%2FHVAC%2FBlowers).

[cyber mouse45]

Hey nihili, I can’t tell from your pic, but dose your duct go over the hsf and all the way down to the mobo, or does it rest on top? Oh, and btw the Fedex dude just dropped of my case two minutes ago so now I’m ready to do some drilling and cutting!! :D :D :D

[nihili]

Originally posted by cyber mouse45
Hey nihili, I can’t tell from your pic, but dose your duct go over the hsf and all the way down to the mobo, or does it rest on top? Oh, and btw the Fedex dude just dropped of my case two minutes ago so now I’m ready to do some drilling and cutting!! :D :D :D

Because I use my duct as an exhaust I extended the duct partway down the heatsink to ensure that I was pulling air from the bottom. That was a thermoengine. My 8045 has a shroud built in to it and is already designed to pull air off the heatsink, so I've just attached the duct to the fan.

nihili

[dream caster]

Originally posted by Darrenct
Here's what I'd love to try...

I have an Alpha pal8045 HS, so it is designed to have the fan suck off of the heatsink. I'd use a duct like Diehrd's to exhaust the hot air out in to the open instead of in to my case.
Then I want to build some kind of housing around just Heatsink, and have cold air blowing in to this housing.
Of course, my $15 mid-tower case doesn't give me much room to try all that fun stuff.

I like the cardboard Idea, it's easy to work with, my only issue is that I have a window, and cardboard looks so Ghetto... I suppose if you painted it... I don't know, the one in the original post on this thread looks so professional.

Here's a rough idea of what I mean... Of course, you'd need as much intake as exhaust.

I think you can easily build your design. If you use a clear or tinted acrylic division parallel to motherboard fitted to the heatsink just at the edge of the shroud and bring air from rear or side panel it is bound to look really good.
It may be easier, though, to reverse flow and have a duct coming from side panel to fan and the exit to the back below the acriliyc so you don't have inlets and outlets of air near to each other.