Radiator fan options - Opinions please

Admiral Huddy

Admiral Huddy

Admiral Huddy

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I’m right tin the middle of rebuilding my new rig and can’t quite decide on my fan set up so was wondering if anyone has any opinion.
I’ve purchased the NZXT Switch 810 to host a triple radiator in the roof. I’ve also bought 3 x 12CM Scythe GT1850s which are to be attached to fan controller. There is a single rear and 2 bottom 14cm case fans

Now there’s a nice area in the roof of the case where the fans can be concealed but on top of the radiator, rather than underneath. Ideally, I’d like to utilise this area and have a few options.

(apologies for basic diagrams)

Option 1.

Exhaust by pulling the air through radiator.

The fans are placed in the concealed area but pull the air through the radiator underneath. You’ll notice I’ve turned the rear 140mm inwards so that the radiator receives cooler air whist trying to reduce the pressure inside the case. So I have 3 fans blowing air in, and 3 fans blowing air out through the roof.. Seems logical to me.

Opt1_zps44fd9148.jpg


Option 2

Inward fans pushing fresh air through radiator.
I’m concerned with this option because there’s only one rear fan for 5 inward fans, creating high and warmer pressure inside the case. I’m not convinced this is a good option.

Opt2_zps3a1df4cd.jpg


Option 3

Forget about utilising the space in the roof and go for an exhaust option but push the air over radiator rather than pull. I’m not sure how this is any different from option 1 tbh. I means the fans slightly protrude over motherboard area.

Opt3_zpsf9aa04b7.jpg


edit - i'd probably still turn that 14cm rear fan inwards. to create 3 in/3 out


I prefer option 1 so I guess my real question is, is there any difference between pulling and push air across the radiator option 1 and 3 respectively?
 
Option 3 for me, that's exactly the setup I have just done in my Carbide 540, except the 240 and 360 are in switched positions.
 
Hot air will rise naturally, so do not resist that by pulling hot air down into the machine, so either of the options exhausting air vertically. Option 1 works for me by pulling cooler air in from the back to pass through the rad. Or option 3 but reverse the rear fan.
 
Ive got a switch 810 and im running pull on the top with a single push in the middle, and again pull out at the front with a single push. Lots of negative pressure though I do want to redo the loop at some point will probably wait till april when its a year old and time for a strip down
 
nkata said:
Hot air will rise naturally, so do not resist that by pulling hot air down into the machine, so either of the options exhausting air vertically. Option 1 works for me by pulling cooler air in from the back to pass through the rad. Or option 3 but reverse the rear fan.
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good point about the rear fan on option 3 .


Do you feel thee's nothing lost over pulling over pushing?
 
I said option 3, but with option 3 you need to also consider which side the fans are (push or pull), as I was talking on purely air direction.

On both my radiators I have them in push. I believe if they're in push, you get less air through due to the center bit of the fan, so it won't cover the whole radiator, where as with push it will just push it through where it can. Maybe I'm wrong, no idea, but it makes sense to me!
 
Addicted said:
On both my radiators I have them in push. I believe if they're in push, you get less air through due to the center bit of the fan, so it won't cover the whole radiator, where as with push it will just push it through where it can. Maybe I'm wrong, no idea, but it makes sense to me!
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I think that statement is wrong somewhere as you said push throughout.
:confused:
 
Admiral Huddy said:
Can i ask why?

The reason i ask is i'm trying to understand if there's any loss of air being drawn over the fins as opposed to push?
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How true or not it is I don't know, but I'd imagine you get the most pressure in push, it also looks better in the case imo.
 
Admiral Huddy said:
I think that statement is wrong somewhere as you said push throughout.
:confused:
Click to expand...

Oops, hold on:

Addicted said:
I said option 3, but with option 3 you need to also consider which side the fans are (push or pull), as I was talking on purely air direction.

On both my radiators I have them in push. I believe if they're in pull, you get less air through due to the center bit of the fan, so it won't cover the whole radiator, where as with push it will just push it through where it can. Maybe I'm wrong, no idea, but it makes sense to me!
Click to expand...

Better =D
 
much better - thank you:D

I'm going for option 1.

When I'm all setup. I might measure the temperature of the water at same point, switch to push then take another set of readings.. Just out of interest.
 
Addicted said:
Oops, hold on:



Better =D
Click to expand...

I thought it was the other way around :confused: That air is only pushed off the blades so push causes a dead spot due to the motor of the fan. Whereas pull causes a vacuum between fan and rad meaning it works better. I though shrouds worked better in pull for this same reason.

Off to find if anyone has done any testing, though in reality I would think it makes very little difference.

Edit: I was wrong apparently, according to martins liquid lab - push is better than pull. Though does leave it a bit open with each rad is different.

Test here: http://martinsliquidlab.org/2012/01/15/radiator-shroud-testing-v2/

He is testing shrouds but also lists temperature details for pull and push for comparison.

Admiral Huddy said:
much better - thank you:D

I'm going for option 1.

When I'm all setup. I might measure the temperature of the water at same point, switch to push then take another set of readings.. Just out of interest.
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Out of the ones you listed, option 1 appears to be the best. Going on how little water temp varies across a whole loop I doubt switching the fan orientation / position will change much but worth testing.
 
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Yep as above, on my 800D i used to run my 360 rad with shrouds and pull, but im limited on space in the carbide 540, so removed the shrouds and moved the fans to push.

In all honesty though, you won't really see much difference, so it depends on looks more than anything!
 
Admiral Huddy said:
That's what I like to hear. Thanks.

What's the advantage of the shrouds?
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Makes the fan more efficient, if you look when your in a chip shop the is a big canopy hood over the fryer, its area is much bigger than the fan it will be connected to (there's also grease filters involved but that's irrelevant to my point) allowing the fans vortex to collect air from a wider range.

With a custom shroud you could cool a 360 with a single fan but the airflow over the fins would be reduced, by using a shroud in equal proportions (one fan per 120mm of rad space) it allows the efficiency of the fans to be increased.
 
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