Cooling Radiator question

Hey Guys,

Right now I’m slowly getting all the parts to add watercooling to my new rig. For now this is what has arrived:



Black Ice Xtreme 2 – Chrome x1
PrimoChill Black Ice Xtreme 2 Shroud x1
Delta 120x38mm Triple Blade High Speed x2
FilterRigh 120mm Clear Aluminum Fan Filter x2

This radiator setup will on the inside top part of the case, so my question is that I’ve seen where the radiator is up against the case with the fans below sucking air in, and have seen them where the fans are against the case and the radiator below it.

Is their a difference or is it just personal taste?

TY Guys

 

Tests have proved that having the fans suck air through the radiator I'd set it up from right to left like this:

Case >> Rad >> Shroud >> Fan

 

i have that same rad and i want to put 4 120mm fans on it. would it be best to have a push pull or have them all blowing onto the rad

 

Push-pull most likely, but it would only take a few hours to try both outside the case...

 

with 4 fans on a 2 fan radiator, you would have to go with a push pull setup, if you had a pull pull (read all fans pulling from the rad) you will get very little air flow throught the rad, if you setup a push push, you will end up again with very little air flowing through the rad. it is air through the rad that cools it, so if you are using the above raid with 4 fan setup 2 to push in and 2 to pull ou air from the rad, and you will get more air movement then with either 2 fans pushing or just 2 fans pulling and you might get a lower temp.

note i said might, because if you are already moving enough air through the rad with just 2 fans (either in push or pull) adding more air, will not cool the rad (and thus the water) any more.

 

Comparative tests with a BIX have shown in the past that a pull configuration works best, with push-pull offering no significant advantage and a push setup being slightly worse.

Don't mess about with unnecessary fans. Just set up two in a pull configuration.

 

I agree with Nexxo ( whatta surprise, eh?) and will add that your "shroud" looks horribly ineffective.
The fans need to be spaced about 1" to 1 1/2" away from the rad to minimize the "dead spot" effect of the hubs.

IMO, the case roof is not the best location for the rad although others will no doubt disagree.

 

Thank you guys for all your inputs.

Yeah, that shroud is only 1/8" thick so it may be to thin. As you can see in the pic below I’m using those 120x38mm 141.96 CFM @ 3700 RPM Delta Tri Blade fans check them out HERE. Want to try them out.



Here is something to ponder... I can see where you would get a "dead spot" when pushing air but would you get a "dead spot" when you’re pulling air? Does that make sense? What do you guys think?

TY Scooby

 

Yes, oh yes, you definitely will.

 

TY clocker, I thought so. I think I'll try to mod one for it.

 

You can always gut a dead 120mm fan and use the housing as a spacer.
Not ideal, but commonly done and better than nothing.

 

...and then buy some airplugs because those fans are going to be LOUD!

 

I will be hooking them up to a Sunbeam 4 Channel Rheobus. I was able to dial them down to about 2500RPM and the air flow and sound was at a nice balance for me.

Right now (7:30am) my computer has been running about 12hrs and my case temp is at 20-21c and my CPU is at 32c surfing the net on air. Hopefully when I install the watercooling setup I may be able to dial it down a bit more and get the same performance.

 

I think the accepted theory now is that is a bad idea and actually impedes air flow. I have cut and pasted a post by BillA from OCAU.com (you have to register to view posts) who did extensive testing on this.

 

Thanks, I was aware of that.

The question remains however, is the impedence worse than having no shroud/spacer at all with the resulting poor draw through the radiator fins (the dreaded "fan hub dead spot")?

 

From that snipet it sounds as if his setup is arranged that the fan blows air into the "spacer" and then the rad, or elso how could the fans discharge be impeded. Am I reading that correctly? If so were test done showing how the airflow is impeded with the fan pulling air through the spacer?

 

Good point Biff.

The shroud allows the air cone to expand so it covers a greater area of the rad while using an old fan body keeps it constriced in a cylinder type pattern. I suppose it comes down your rad. If the cylinder of air covers all the fins of your rad then its probably not going to make much of a difference but if its smaller as it often the case with a heatercore then its reducing performance.

Clocker i don't know and will have to go back and read the article again!

 

I don't believe that it says anything definitive about that particular scenario, but I could be wrong.

I have used gutted fans several times and despite their theoretical shortcomings found they were better than nothing. This could be due to my fondness for oversized rads too...sheer surface area might make up for poor airflow.

One thing is certain (at least to me)...spacing the fans away from the fin matrix will certainly decrease the perceived noise of the fan, which is a good thing no matter how you achieve it.