Where can I get a CPU heatsink-to-exit-fan plastic duct?

[Ken90630]

I saw a new Dell computer the other day that has one of those green plastic ducts that hangs over the CPU's heatsink and directs the hot CPU-generated air directly to an exit fan on the rear of the case. Unless I'm missing something, this looks like a GREAT design idea. (Keeps most of the hot CPU air from emanating out into the case.)

Anyone know where I can buy something like this without having to buy a whole Dell computer? I'm upgrading my basic PC and would like to do this. I can fabricate one, but would rather save time and just buy one.

Ken

PS: Does anyone familiar with Dells know whether there's a fan over the heatsink on computers equipped like this? The model I saw was a Dimension 2400 with a P4 2.6 GHZ CPU. (It's not mine, and I didn't have the opportunity to poke around.)

PPS: I posted a semi-similar question awhile back, but it had to do with PSU ducts. This is different.

 

[fireontheway]

i'm not sure if this is what you're looking for but it comes close to your description.

 

[Ken90630]

Different looking product, but yeah, it's the same idea. This actually looks like it might be better since it's completely sealed. Thanks.

Can anyone think of a reason why we shouldn't all be using one of these?!

The only thing I wonder about is this: The heatsink fan over the CPU is blowing down onto the CPU to help dissipate its heat, right? Well, if that fan is blowing down onto the CPU but there's a case exit fan & duct sucking air away from the CPU, will there be some push/pull conflict going on between the two fans? There'd have to be.

Maybe one of these ducts could be installed and the heatsink fan disconnected entirely. Wonder which would cool better. Any hypotheses or theories, anyone?

 

[fireontheway]

you can choose either one, blowing cold air in or sucking hot air out. but most likely blowing cold air would be a better choice. just keep in mind the every system is different, so you may want to try both configurations and see what works best for you.

 

[Ken90630]

I knew you were gonna say that! I just don't have the time to hook temperature sensing equipment up and do some testing. But hey, think about this: When you say, "but most likely blowing cold air would be a better choice," the CPU fan is not actually blowing cold air onto the CPU -- it's somewhat warm air from inside the case that's merely being directed onto the CPU to help dissipate its heat out into the case (as opposed to room-temp air coming in from outside the case). Right?

Kind of an intriguing subject, I think. Wish we could get some more input & get a small thread going (hint, hint). I wonder if anyone's ever tested temps on a CPU with both methods to see which is better.

Or maybe it's late and what's intriguing to me is of zero interest to anyone else. That's always a possibility ....

Buenos noches.

 

[fireontheway]

yes that is right. but what im trying to say is,with this kit you will have the option of blowing outside air (cooler temps) directly into the HSF.

 

[fireontheway]

yes that is right. but what im trying to say is,with this kit you will have the option of blowing outside air (cooler temps) directly into the HSF.

 

[SneakyStuff]

Yep, i've got sheathes oone of those green on my Dell, and it works very well, the only problem is that it doesnt give much airflow to the rest of the system, I remember my old pentium II made by Dell, it had a 92mm fan in the rear, with no sheathe, that was right next to the processor, since it was open it sucked air from the entire system, and let me tell you that thing pushed some HOT HOT HOT air out!

 

[Zepper]

I think that bringing cool outside air directly to the HS will cool both the CPU and all the air inside the case some. The better way. Some that have used that duct kit have mounted another fan at the outer end of the duct - they say it helps. My case has two 80mm fan mounts at the rear and I intend to use one of them for a duct kit in the not too distant future.

 

[Blain]

If you use the duct to bring cool air to your HS, make sure and add some kind of filter on it. Dust collecting on your HS will do it no good.

 

[0roo0roo]

ducts can cut airflow from the fans, so its not totally free bonus cooling. the hot air still goes into your case. most people try to cool the entire case so they can make sure all components are nice and cool. uber cooling your cpu has no point really unless your trying to overclock

 

[KillaKilla]

Originally posted by: Ken90630
I saw a new Dell computer the other day that has one of those green plastic ducts that hangs over the CPU's heatsink and directs the hot CPU-generated air directly to an exit fan on the rear of the case. Unless I'm missing something, this looks like a GREAT design idea. (Keeps most of the hot CPU air from emanating out into the case).

[brain-fart]
Wouldn't having a duct going from the CPU HSF sides do this, rather than a duct leading from the outside to the CPU HSF intake? This would allow other components to stay a bit cooler, seeing as the CPU heats up most of your case (usually). You could also do both, thus allowing the entire system, CPU included, to stay cooler. Having a duct from the CPU/HSF out would require having different ducts for each Heatsink, because of different HS heights. This would also allow a closed CPU cooling system which would pull more air through, because there would be a total of 3 or 4 fans blowing the air through.

It would also be quieter, because the CPU fan would be hidden behind the ducting, which you can then put a sound guard over the exhaust to block the noise.

[/brain-fart]

 

[L00PY]

Originally posted by: KillaKilla

Originally posted by: Ken90630
I saw a new Dell computer the other day that has one of those green plastic ducts that hangs over the CPU's heatsink and directs the hot CPU-generated air directly to an exit fan on the rear of the case. Unless I'm missing something, this looks like a GREAT design idea. (Keeps most of the hot CPU air from emanating out into the case).

[brain-fart]
Wouldn't having a duct going from the CPU HSF sides do this, rather than a duct leading from the outside to the CPU HSF intake?
[/brain-fart]

On my work Dell there is a PSU fan and an rear exhaust fan -- that's it. Air is drawn up along the sides of the heatsink, through the duct, and out the exhaust fan. There isn't a fan mounted on the heatsink. You could duplicate the Dell effect on cases with a side duct by reversing the HSF and sucking air off the HS instead of blowing down onto it.