Fan shroud on a Black ICE Extreme rad?
 

I'm curious, with a Black ICE Extreme radiator and one 120mm Papst fan pulling air through the radiator, how much benefit would I get from using a shroud? Does it make much performance difference? Noise difference?

Assuming it's worthwhile, any recommendations on who sells the best ones online? (Not looking to make my own shroud quite yet, but looks like it could be a fun project.)

I always thought shroulds were for heatercores to fix a standard size fan onto a not so standard HC design.

The Black Ice Rads I got fix fans on no trouble... with little of no gap between the two. I would have to ask why would you need one? Unless of course you are puting a larger/smaller fan onto your 120/80 rads.

~ Boli

I've read in various places that having a fan with the blades running that close to the fins in the radiator produces noise, due to their close proximity. Also, I've read that it's less efficient that way.

I wanted to run it by you guys to see what you thought and how much truth there is to that.

It is absolutely true. I used the nylon threaded posts and nuts that came with my Maze2 to elevate the fan about 1.5" off of the Black Ice rad. Then I just took a piece of aluminum flashing and bent it to fit around the posts and riveted it together. Took maybe 5 minutes.

Having a shroud eliminates the dead zone caused by the hub of the fan and helps to focus the air to one point, making it more efficient. But the fan needs to be about two inches away to work effectively. Shrouds can be used for heatercores to place a fan on or on rads with pre-drilles holes for a fan.

Don't know much about eliminating noise tho.

a nice looking tutorial can be found half way down the page

http://forums.procooling.com/vbb/sho...&threadid=6887

Here is a pic of my BIX:

http://www.procooling.com/~phaestus/bixshroud.jpg

That is only 1" tall because that was as large as I could make it and get it to fit.

Here's my current rad:

http://www.procooling.com/~phaestus/becoolingrad.jpg

2" clearance between the fins and the fans.

I highly recommend reading this article:

http://www.nmbtc.com/pdf/forum/engineering_101.pdf

Page 3 has P-Q curves for fans with restrictions at different lengths from the fan on either the intake or exhaust side. This is the "why" for using a shroud rather than strapping fans right onto radiators.

Last time I saw pHaestus post that lower link I decided to experiment a bit myself. I took the 120mm fan off my BI Prime (which has mounting the same as a BIX), cut up some cerial-box, and taped together a cardboard shroud real quick (then taped it to the rad and taped the fan to it - I have a lot of tape holding my water-cooling together in places). Moving the fan an inch away from the rad (all I had clearance for) got me an extra couple degrees. Exact temps don't matter much (specially since they are socket-thermistor temps), but since I didn't even remove/re-mount the block to do this my before/after temps should be fairly comparable.