Fan question regarding fans on both sides of rad, static pressure, shroud/no shroud

[arfett]

I've got a PA120.3 as per my sig and currently have 3 1600rpm slipstream fans on the top pulling air out the top of my case. I'm soon ordering 3 more to put on the bottom and in my head it would make sense that if I were to close off any openings (shroud the fans or use tape to just cover up any openings around the fans which is what I've done to the top fans to ensure any air being pulled by them is coming through the fins) that it will increase the pressure inside the radiator and allow much more airflow out the top of my case because any air not going through the fins will not blow back between the openings of the fans. Is this theory of mine correct or is "shrouding" them going to decrease the efficiency of the radiator?

[Conumdrum]

Too hard to read, sorry.

[Talonman]

My guess is your splitting hairs. :)

Shrouding or not shrouding won't change your RAD'd performance enouigh to measure, providing it's getting decent air flow already. I don't believe much would change.

I think the shroud is more for looks, rather than performance.

If the air your pulling is hot out the top of your case, that could change things.

Put a thermomiter on the top of your case, and compare it to the rooms temp. Is there much of a difference between the two? If not, I wouldn't sweat it.

[arfett]

The problem isn't the temperatures, it's the CFM. If I had to guess I'd say I'm getting 1/7th of my fans free air performance out the top of the case.

[Eddie3dfx]

Actually, I just read somewhere on overclock.net about a performance test a guy did with shrouds
It actually helped out quite a bit, make a 2-3c difference in temperature I believe.

[Talonman]

Wow... I am suprised by that.

[STEvil]

Why?

Its long been known what shrouds do..

[arfett]

At this point I wouldn't even really care if there was a huge difference in temperatures, but I think the pressure these fans create is very small and in theory putting fans on the other side should increase this pressure allowing for more air to come out the other side. Would the shrouding effect cause more air pressure to build up?

[Serpentarius]

if you have the space, shroud is handy .. but is it worth it? considering the thickness of the shroud (space wastage, and the cost?)

if u really want performance .. u should get 3 more fans on the other side of the rad .. i heard can improve performance up to 20% .. but the side effect .. 50% extra dBA

[STEvil]

close up any gaps. gaps mean you lose static pressure. pressure = performance.

[arfett]

As this was kind of explained to me in another post my problem is air pressure since my fans don't create as much static pressure as some fans. So in my case I'm thinking shrouding may in fact make a difference. I'm just trying to understand the science of the static pressure and the effects of shrouds on it.

[perfectdarth]

slipstreams dont have much static pressure, sflex would be better and probaly quieter.

[Talonman]

Why?

Its long been known what shrouds do..

Well if it is as well known as you say, we should officially add to a stickey that by adding a shroud, you will see a 2-3c difference in temperature then.

We all buy different blocks, and tims to get the same results. A shroud is cheep.

Do more members also feel as STEvil does, that is is common to get such results?

I still am still suprised that a shroud can move your temps lower by a few °C...

[Eddie3dfx]

Here is the test someone created on shrouds. It is a sticky, just not on xtremeforums.

http://www.overclock.net/water-cooling/204770-part-1-temp-s-out-shrouds.html


Here is a little snippet of info found in the benchmark above

Comparisons......

Push-Pull with shroud average below ambient.....23.375C...3.625C cooler

Push-Pull with-out shroud average below ambient........19.75C
--------------------------------------------------------------------------------------------------------------

Pull only with shroud average below ambient.........21.125C......3C cooler
Pull only with-out shroud average below ambient..........18.125C
---------------------------------------------------------------------------------------------------------------

Push only with shroud average below ambient......20.25C.....2.375C cooler

Push only with-out shroud average below ambient..........17.875C

[Talonman]

Impressive for sure.... :up:

[leo_bsb]

I recently installed a shroud on mine PA120.3 and didn't notice any difference at temperatures, loaded or idle.
The noise is lower anyway.

[Navanod]

Impressive for sure.... :up:

Shroud helps to reduce the dead air space at the fan hub...means more fins on the rad are actually working...depending on how many fans are on the rad, some improvements are expected?

[Navanod]

slipstreams dont have much static pressure, sflex would be better and probaly quieter.

Agreed...unless we're talking bout the 1900rpm slipsteams. :D
Also, if these fans are blowing "upwards", I fear for their poor sleeve bearings
Rather than get another set of slipstreams or a shroud...perhaps it would be easier to change the fans?

[arfett]

I already have some 2000 RPM Ultra Kaze fans. Does anyone know if these have good static pressure or should I grab the S Flex fans?

[_Slim_Shady_]

Yate Loons work great with the PA. They are less than $5 too! :)

[Xilikon]

Ultra Kazes is much better so give it a try as you already own them ;)

[Subsider]

Theres a thread here on push - pull - shround - no shroud . good read http://www.xtremesystems.org/forums/showthread.php?t=99721