What is a shroud

what is a shroud?? i checked the stickies but no luck

it's like a vent between a fan and whatever it's cooling, so say you're cooling a rad, ther fan would bolt onto the shround (like a very short tunnel)and the rad onto the othr side of the shroud, this eliminates pressure loss and reduces the dead spot on a fan.

thanks

cool, i was wondering this as well, is there a big difference when you use this?

I don't personally know, I assue there is as everyone does it, it would certainly help for the dead spot on a fan where the motor is.

there was an actual chart done.. basically a good shroud should place the fan about 1 inch from the actual rad. this basically eliminates dead spots and increases efficiency of the fan.. so always use a shroud when you WC

I think someone said on their particular system is made a 1-2C difference, but of course that should be taken with a grain of salt. I think the sweet spot for distance is 2"

reduces noise and increases performance, especially when used to suck through the rad/HC.

I saw a drop in temps going from a double 120 HC with no shroud to a single with a shroud.

You should not consider shrouds optional on an HC.

With a HC I would say a shroud is a must have. Also the sweet spot is 1 1/2" depth on the shroud.

if you have to balance space considerations against shroud standoff - the minimum standoff should be no less than 25mm

a good balance between size and standoff is 38mm of standoff which puts the typical 50mm thick core right at 5" thick after a 38mm x 120mm fan is mounted to it.

other than that, the usual formula for guestimating theoretically optimal standoff is: standoff = width of the fan hub [which is usually right at 50mm on a DC 120mm fan]

the difference in temp between 38mm standoff and 50mm standoff?
dunno - my thermistors can't tell a difference in coolant temps between the two but there is likely an ever-so-slight edge with the extra 12mm standoff.

For the record, the usual standoff on commercial rads or the flat plexi "shrouds", which is normally around 10mm-12mm, is basically pathetic.

edit: the performance difference between a core with no shroud and the core with a proper shroud is approx. 40% improvement in favor of the core with the shroud.