Ninja duct/shroud (with instructions) that took ~6c load off

niels007 · Post by **niels007** » Thu Feb 19, 2009 7:23 am

Hello all,

In my case load temps went from 82 to 74, which is 8 degs, but its a bit cooler in my room so I mentioned 6 degrees.. It might not work for everybody! Since it did in my situation here is the plan:

Edit: one dimension is missing. The angled line right to the two 'lips' is 25mm LONG

That folds into a 3 sided cover / duct with a tappered bit so you can fit a 120mm fan at one end, then it goes to 110x110mm and covers the Ninja tightly; meaning the air must pass through the heatsink and can't escape through the sides. I use thin strips of double sided tape to secure a 120mm fan to the duct, also giving it rigidity. I used thick paper, thin cardboard will also do.

A poor picture explains somewhat better; I used that ''A-team / MacGuyver'' tape to fix the ends together.. I never cared about 'pretty'..

Works wonders for me!

Also, it might help to change the orientation of the ninja (in my case that left 1mm between heatpipes and NB heatsink) so that the small heatsink on the base is also angled such a way that airflow passes through it rather than bumping into the side.

/Niels

blackworx · Post by **blackworx** » Thu Feb 19, 2009 7:41 am

Good skills!

(Reasons why I heart SPCR #42)

psiu · Post by **psiu** » Thu Feb 19, 2009 8:44 am

Is the Ninja mounted properly? Isn't that ridiculously hot with a Ninja on any processor?

niels007 · Post by **niels007** » Thu Feb 19, 2009 9:11 am

I reseated it, it seems to be on alright; perhaps the base isn't quite flat.. Its a E8400 dualcore at 4ghz and 1.55V in the bios (1.42 load) which is pretty hot but I agree, I didn't expect to be near 'danger' even overclocked.. The whole cooling thing is debated here: viewtopic.php?t=52486

The fan duct/shroud/whatever might work regardless of my hot cpu though

xan_user · Post by **xan_user** » Thu Feb 19, 2009 9:26 am

Nice ducting.

It seems that the temp are a bit high, but safe.

If it was my rig id want to find out why tho-

Bad paste?
Bad cpu heat spreader?
Bad ninja?
Bad temperature readings?

At the saying goes if it aint broke, dont fix it.

Now, if I could only heed it...

jhhoffma · Post by **jhhoffma** » Thu Feb 19, 2009 10:05 am

Duct looks good, though you're probably not using the fan at full efficiency because of the reduction in cross-section area. No different than using one of those funnel adapters for using a large fan on a small mount. You end up making things worse by adding backpressure onto a slower moving fan.

I might look at making the duct bigger and surrounding the entire heatsink.

I thought your temps were out of whack but then I noticed how small your case was, and then I though about how much intake is coming in, where's the PSU, etc? It would help if you let us know a little more about your setup (case, mobo, PSU, and other fans).

Oh, and this is a "duh" thing but when there's so many people from the US mixing with the rest of the world, I'm only confident in numbers when units are attached. I gotta know if we're talking C or F, kW or hp, lb-ft or N*m, y'know?

QuietOC · Post by **QuietOC** » Thu Feb 19, 2009 10:50 am

jhhoffma wrote:Duct looks good, though you're probably not using the fan at full efficiency because of the reduction in cross-section area. No different than using one of those funnel adapters for using a large fan on a small mount. You end up making things worse by adding backpressure onto a slower moving fan.

I might look at making the duct bigger and surrounding the entire heatsink.

Funnels work just fine. Sure, they incease backpressure, but they also keep the air doing something instead of nothing. Making the duct bigger will just allow a lot of the air to bypass the heatsink fins completely.

I do think a duct on the Ninja works better with the fan on the otherside pulling air, and the duct leading outside the case, but I haven't tested both ways.

psiu · Post by **psiu** » Thu Feb 19, 2009 11:39 am

jhhoffma wrote:Oh, and this is a "duh" thing but when there's so many people from the US mixing with the rest of the world, I'm only confident in numbers when units are attached. I gotta know if we're talking C or F, kW or hp, lb-ft or N*m, y'know?

Says 'c' in the topic title.

niels007 · Post by **niels007** » Thu Feb 19, 2009 12:00 pm

A *very* long time ago, when SPCR was still a yahoo message group board thingy, I tested various ducts and came to the conclusion that there is little difference in *how* you go from one diameter to a smaller one (or being square) I.e. over a short or long distance didn't matter. That was many years ago and I have no idea where my little writeup is now!

From 120x120 to 110x110 isn't that much anyway.

QuietOC · Post by **QuietOC** » Thu Feb 19, 2009 12:15 pm

niels007 wrote:A *very* long time ago, when SPCR was still a yahoo message group board thingy, I tested various ducts and came to the conclusion that there is little difference in *how* you go from one diameter to a smaller one (or being square) I.e. over a short or long distance didn't matter. That was many years ago and I have no idea where my little writeup is now!

Some length does help. Merely blocking off the edges of a fan does work, but not as well as a short funnel. Axial fans in open air have a large dead zone in the middle of the exhaust side, so you can use a funnel to direct air back towards the center of the heatsink.