What heatsink is good for sucking fans?

[ThePanda]

Hi. Can anyone tell me what is a good heatsink for fans that suck air off the heatsink rather than blowing onto it? I want to run a duct to a 120mm fan on the back or front of my case. Right now I have the heatsink left over from my Volcano II, although I think that is meant for the fan to blow onto it.

Also, does anyone know where I can order a duct that would work good?

Finally, does anyone know the best way to attach the duct to the heatsink? :eek:

Please help me out if you can b/c I would like to do this before college starts.

Thanks for any suggestions

[It_The_Cow]

Alphas are usually designed to suck air through the fins, but you can do it on any heatsink. You can probably make a good adapter out of cardboard, or attach the fan to the side of the case and use on from plycon.com. AS for attaching it, you can use the all-mighty duct tape

[ThePanda]

I was planning to mount the 120mm fan on the front or back of the case and run some kind of tube to the heatsink. The thing you mentioned on plycon.com, is it their "CASE FAN DUCTING?" Is that long enough to reach the cpu or is it just to mount it to the side of the case?

Also, should the tube be taped around the heatsink? It seems to me that if I did this and had the fan blow air away from the heatsink, there would be no air for it to blow..

[outhouse]

why not have the duct suck cool air in from outside the case dirrectly to the fan on the HS and have the air blow down, your temps will be much cooler as your nor drawing warm case air to cool your CPU with even with good case cooling your temps will still be 1 to 3C hotter. Also ducting this way is much more efficient then trying to aim air with a duct to 2 sides of a HS.

[ThePanda]

The fan doesn't have as much efficiency blowing in through a duct b/c the pressure backs it up (and also I would need a filter on the fan which could get clogged up). Also, I want to get rid of the fan on the heatsink so it will be quiet.

[William]

you loose efficency though the longer the duct. Would be interesting to see the results.

[outhouse]

Originally posted by ThePanda
The fan doesn't have as much efficiency blowing in through a duct b/c the pressure backs it up

leaving the fan on the HS the way it is will fix that problem.

also I would need a filter on the fan which could get clogged up)

if you want cool air coming in the HSF you will face this problem either way.

. Also, I want to get rid of the fan on the heatsink so it will be quiet.

No problem do the silicone trick and it turns the Delta into a normal sounding fan.

I guess what i'm trying to say is to get the best temps with the least amount of work air blowing down is easier but if you make sucking work more power to you :) let us know how it worked.

[ThePanda]

I haven't really seen detailed descriptions of how to do anything like this, and I still don't even know where I will get duct material, but I was thinking that I probably need to leave a space around the heatsink somewhere so the air will be able to get into the tube to get sucked out. Or maybe I could have the heatsink completely enclosed and have an intake duct also going to the outside of the case but I think that might be too complicated for me :D

[ThePanda]

Would: Thanks for the suggestions, but I think I am too interested now and have to try the duct exhaust thing :D. Should I look around at Home Depot or somewhere to try to find something for the duct or is there some material designed for this type of thing that I could find online somewhere?

[The Overclocker]

there is a plastic ducting stuff you can get theat is designed for showers, i have only seen it in a 120mm vesion though, if you want a heatink good for sucking just use any heatsink but put a longer skirt on it(use tape) forcing air to came in the bottem

[ThePanda]

Originally posted by the overclocker
there is a plastic ducting stuff you can get theat is designed for showers, i have only seen it in a 120mm vesion though, if you want a heatink good for sucking just use any heatsink but put a longer skirt on it(use tape) forcing air to came in the bottem

the overclocker: sorry, but can you tell me what a skirt is?

Would71: I think I would need a more powerful and louder fan to counter the pressure and stuff if it is blowing in. I want to use a Panaflow 30dB @ 68.9CFM. I was going to try to put a second one too to blow some fresh air to the base of the heatsink.

[rodvon]

you mite want to look at the core by CPUfx Inc. I havent tried it but it look like it would be idial for a duct system. you can buy one at http://www.overclockershideout.com/core.shtml

[ThePanda]

Would: Thanks for the diagram. I'm still not quite sure what I will do.

rodvon: Wow that thing is expensive! :eek: But you're right, it does look like it would be good for a duct system.

[rodvon]

dam that is a lot try https://www.cpufx.com/Merchant2/merchant.mv?Screen=CTGY&Store_Code=o&Category_Code=C you can just buy the core heat sink and fan for 45.99 $us

[Intraveinous]

The Zalman 5000+ is a very good sink for sucking air through. The best part about it is it already has a shroud/skirt on it it.
Basically, think of it like this:

Normal heatsink Shrouded/Skirted heatsink

| | | | | | XXXXXXXXXXX<--Shroud
| | | | | |<--FIN XXXXXXXXXXX<--Shroud
|_|_|_|_|_| |_|_|_|_|_|_|<--FIN
^BASE ^BASE
Where the X's represent something covering the top of the heatsink to make air coming in come from the bottom.
If you do not have a shroud of some kind, the fan will suck all the air from the top of the fins area, leaving the very hot base plate and bottom of the fins mostly uncooled. Something as simple as wrapping the heatsink in electrical tape and leaving part at the bottom uncovered will work, but you can build something out of cardboard/paper, plastic, metal, or whatever you want. The amount of space to leave at the bottom depends on the size of your heatsink, the size and output of the fan you're putting on it, etc. As far as ducting goes, has anyone used dryer hose? The flexible plastic/thin metal stuff that you connect your dryer output to the outdoor vent with...
Anyway... Hope this helps.
Peace
John
PS: From all I've heard, the Core is no good, price/performance ratio is WAY lower than a ton of other heatsinks.

[Intraveinous]

Ack! Blast!
The ASCII art looked fine on my screen :(
Oh well, I hope you got an alright idea even without the diagrams.
John

[ThePanda]

Would dryer hose short stuff out?