Duct to HSF?

[sanaka]

How bout a case hole right across from the CPU and a duct right to the HSF? So the HSF would be getting ambient air direct, not preheated, already-travelled-through-the-case air. Plus its own dedicated inlet, no flow obstructions.

I'm a newbie trying to design my overall coooling setup.

 

[mstudd]

Yeah, I did it on my system with a fairly high flow Sirocco 80mm (can't remember the CFM) and it's awesome, lowered my CPU temps by about 5degC.
It actually runs cooler than with the case off!
For ducting, I found some PVC plumbing fittings, which adapted pretty easily onto the fan.
Go for it!


Of course you need some exhaust fans in the top of the case and probably a good fan in the front/lower as well.

 

[Electric Amish]

I'm working on something similar, except it's going to be an exhaust. 120mm fan ducted directly over my Alpha HS. 120mm fan intake at the front of the case.

120mm fan on the HS will better than triple the CFM of the 60mm that is currently on the HS.

amish

 

[chuonthis]

So which design would be better? Fan sucking or blowing? It depends on the what the fan on the heatsink does right? If the heatsink fan blows on heatsink, make the outside fan suck and if the heatsink fan sucks on the heatsink, make the outside fan blow?

Edit: This is referring to a slotket setup with the duct aimed at the cpu.

 

[Electric Amish]

Yes it depends on the fan on the heatsink. The fan on the duct should be doing the same as the fan on the HS and you probably don't want a ducted exhaust fan if you already have a fan on the HS. With a duct, they would be counter-productive.

With the duct I suggested I won't have a fan HS.

amish

 

[sanaka]

I think mstudd did what I mean - which is a passive duct to the cpu's HS fan itself (which is attached to and blows down on the HS). The duct doesn't have its own fan. so the HSF just has unobstructed ambient air intake (filtered) and contributes to overall case air intake as well as cool the CPU.

I vaguely remember a thread where someone *removed* a setup like this but I don't know why - could the resulting 'floor to ceiling' column rising in the moddle of the mobo catastophically disrupt overall case airflow? This is the only question really holding me back

Cheers

 

[McCarthy]

BTW, Pringles cans make nice ducts for 60-80mm fans. Er, uh, if the hardware store's closed I mean. Hey, easy to modify for mockups

 

[amdskip]

also, a needed ingrediant

Ducttape

 

[Lithium381]

why would you want a passive system over a fan within the duct? how would it be counter productive as long as they were both going the same way? also, circular objects(mostly round, elliptical work okay, but not as well) dont' disrupt airflow, air simply goes around it and i THINK it sorta builds up force on the center




> >
> > ooo > >
> > o o >>>
> > ooo > >
> >

(pretend that's round)

at least that's what i seem to remember....

 

[sanaka]

Lithium - I'd like to know more about the air just 'goes around' round objects concept (guess i didn't really get your diagram) and,

true, another fan in the duct would of course jack things way up (well, down, temp wise), but there's an extra fan involved and it just seemed like the HSF having its own private ambient air source would be a huge improvement by itself over (the typical) always using 'case' air, knowwutimean?

Seems like the HS fan itself would also act as a general intake fan too.

But I'm nuts, so...

 

[Blain]

You can get some cool ducts here.
5.9 at Reseller Ratings.

 

[Electric Amish]

If you have 2 fans in a ductwork, they must be identical and synchronized otherwise they will just cause interference with each other. Better to just have one fan (IMO).

Also, I would, personally, use a duct that goes to a HS as an exhaust rather than an intake because you are sucking cool air into the case, over the HS (where it heats up) then into the case.

I prefer to have a large intake of cool air at the front of the case and use the exhaust duct over the HS to draw that cool air over the HS (where it heats up) then imediately exhaust this now warm air directly out of the case.

amish

 

[mstudd]

My duct consists of an 80mm fan attatched to the side cover with a metal grille and a plastic duct which sits over the 60mm CPU fan.
It lowered my CPU temp by 5degC. I tried it without the fan and it hardly made a difference.
I'm not doubting anyone elses theories, but this setup wokrs in MY system.
The best way to improve your cooling is by experimentation.