Pull is better than push right?

I read somewhere on these forums that pulling air through the radiator is better than pushing. Is that still true? I can't find the thread I read as I can't remember enough to search for it.

IF that is still true, I am in need of advice for my current case. It is a modded lianli pc-75b with a Black Ice Extreme 3 on teh inside-top of that case. It has 3-120mm fans. The way the radiator was set up, the fans pull the air from the outside and blow the warmed air through the case. SHould I change this? Common sense tells me yes, but will I see a noticed improvement?

CreeP
TIA

It you change it you will probably get less noise but it's not that big of a deal with performance I think.

I think performance is basically the same, but most people get better noise performance with a pull configuration.

Should I just turn the other case fans to expel air from the case? I would have thought that extra heat in the case would be a bad thing. Welll maybe not if the major parts are watercooled anyway.

^^ exactly.

Yeah if you are using the fans on the rad as an intake, then you will need fans in your case as exaust.

its better imo that you pull the air through the radiator, so the air from the outside gets pulled inside, through the rad, through the 3x120mm fans, and expelled by other fans, but the xtreme3 is designed with mucho surface area so you dont need to blast your fans on high speed to cool it

The way I've always thoought about it is that for our usually short depth shrouds, it's better to put the fans in pull config.
I think that the fans pushing still creates the greatest pressure against the rad in a small doughnut patern. When it's pulling it's creating a pressure drop against the whole surface of the rad's outer face, so all the fins see a fairly equal airflow.

With a long shroud however, that rule of thumb would change as the air pressure would have a greater chance to equalize inside the shroud. As Cathar's engineer friend alluded to, a shroud that's 5 times a fan's diameter in depth is ideal, but if size is a problem I think pulling is the way to go.

As for the second part, I don't think changing your setup would help cpu temps by much, but would help mobo/component temps. Having your rad blow into the case will raise the case air temp further than it would normally go.
I wouldn't change your setup myself, because I wouldn't want to use the cases normally warm air to cool the rad.

if i am understanding you correctly you have your fans that are attached to your radiator pulling air in from the back of the case through the radiator fins and into the case. WHY?!
If you're looking to make your case cooler also, you want the hot air to leave, correct? It wouldn't make any sense to have a WC system if you're just putting the heat back into the case. It's one huge circle. The point of your WC system is to draw heat into the water, move it through the radiator fins and EXPELL the heat with fans out the back of the case. If you had the air being pulled into the case, what's the point of wasting all that money on water cooling your system? this is just my opinion, but it seems physically logical to me. Heat out!

Air being pulled through the radiator into the case?

........ how much dust does it suck into the case in a week?
a month?

flip it over and have it pull the air from the case through the rad.

Well it seems as though almost everyone pulls air from outside, through the radiator into the case, and then exhaust out the back of the case. How much do you think that Rad is going to heat up the air if you have good flow through your case?. 120 MM fans move a lot of air. 2 in via the rad, and 2 out via case fans is my current plan/config.

The point is, why would you put warm air back into the case? The whole reason there is a water cooling system installed is to remove the heat more effectively, right? It would be pointless, you're just circulating heat.

capneedle said:

How much do you think that Rad is going to heat up the air if you have good flow through your case?.

Click to expand...

And to answer your question, the radiator in theory should be heating the air almost as equally as the the parts themselves would heat the air without the WC system. There will be some heat staying in the water itself, but mostly the air will be roughly the same. I understand what the thought process may be: Pull cooler air over the radiator fins to cool it, but you want to get rid of the heat, not circulate it. If the air being pulled in was say, pre-air conditioned, then that would be great, but most likely it's not.

I don't think the heat from the rads will make a huge difference to case temps, at least not with 3 of them.
Consider this. Panaflo low flow fans are ~68cfm. One of the slowest fans out there.
Say for arguements sake that the flow is cut by %75 by the radiator and case/fan backpressure.
Now 3 fans still would (in this thought experiment) equal 51 cubic feet per minute of airflow into a case that's only 2-2.5 cubic feet if that.
It makes it kind of a non-factor in my mind.

My fave way of mounting the radiator has always been sideways (perpendicular to the case front), so that there's a fan at each side of the case, with the rad sandwiched between. Cool in, warm out, no case air involved.
Kindof hard to do with a triple rad though...

push and pull is best if you can fit the fan in there

GL

Why can't you just put some sort of duct on the rad and use your 80mm fan on the case door to pull back out of the case? That why your sucking air from the outside and pushing the air right back outside, the heat never goes inside the case...?