Fans On Radiator?

How much does having powerful fans on radiators affect? Comparing too having good ones with shrouds/having good ones without shrouds/having none

i have a core.. roughtly 7x9x2.......
panaflow med 120mm @ 12v: 38load
panaflow med 120mm @ 7v: 45load
panaflow med 120mm @ 5v: will not stop rising
cybercooler 5 dollar fan @ 12v: 41load

no shrouds on any of these.. just placed or attached pointing towards the centre of the core

I have found that a shroud and cheap fan will always yield better temps than no shroud and an expensive fan, as the question was asked. A fan on a core with no shroud will cool effectively, but not effieciently. Look at it this way, if you have a fan on your core with no shroud you get an "eye of the storm effect" where the only part of the rad that gets cooled is where the fins of the fan are spinning, but not the center or the outer edges for that matter. If you place the fan on/in a shroud about 1"-2" away from the core, pulling through the core, you will be cooling the entire sufface area of the rad.

Liss said:

i have a core.. roughtly 7x9x2.......
panaflow med 120mm @ 12v: 38load
panaflow med 120mm @ 7v: 45load
panaflow med 120mm @ 5v: will not stop rising
cybercooler 5 dollar fan @ 12v: 41load

no shrouds on any of these.. just placed or attached pointing towards the centre of the core

Click to expand...

thats a humongous difference. Have you ever tried two panaflos? one pulling and one pushing, both at 12v?

HOWEVER....

If you have a big enough resovior, your temps will remain fairly stable for quite sometime with no fan on the radiator.

I discovered that in my particular setup (tbred A 1800 @2ghz 1.85v) heat was not my limiting factor- limits of the core were. Therefore, I didnt need to added effects of pelts, push pull fans on radiator, etc. I use a 1 gallon apple juice bottle for my res. and it works great. I have a 7x10 copper radiator with no fans.

Dont get me wrong- your cpu will heat the water up over time, but it is very slow with that much h2o (1 litre res. excess) in your system. Remember, you are not running the hot water from the bathtub into your coolant loop, just 80-90 watts from your cpu.

With a Maze 3, I noticed a increase of 10C over a period of about 6 hours. This brought my temps up from 40C to 50C under full load of Prime95. Room temp roughly 22C.

NOTE- I only use this setup when silence is paramount (games- ie System Shock 2, etc.) Under normal condidtions, I do run 1 120mm at 7 volts and this keeps my full load temps around 42C.

I would be interested in any feedback on this idea. Shrouds and fans are nice, but depends on the application. Closed loop systems need not apply.

Yes A resavoir will cause the water temps to rise much slower, because the more water there is, a higher thermal capacity for heat is available. With a resavoir you could use a device such as a Digital Doc 5 that can be set to turn on fans if i temperature goes over a certain limit. If the digital doc measures the water temperature to be at say 32c it could then trigger the fans to turn on and cool it down a bit.
Only problem that I can see with this method would be the fact that your fan might be clicking on and off throught the day.