280mm Front-Mounted Radiator: Intake or Exhaust?

[zjuventus14]

I recently installed a Kraken X61 in my S340 case. I am aware that radiators are generally used with exhaust fans, however, it is also common practice for the front fans to be intake in a PC. For those that do not know, the case allows for two 140mm fans on the front/280mm rad, a 120 or 140mm fan on top, and a 120mm rear fan. The radiator can only be in front, so what is the optimal fan configuration for the radiator? Also should I use the NZXT FN-V2 140mm that came with it or my EKWB Vardar 140mm-1150RPM fans?

Thanks for any help

 

[DonQuixoteMC]

I hope I'm not misunderstanding, but are you saying that the only place for the radiator is in the front?

Unfortunately, mounting the rad as a front intake fan would be very counter productive, as you'd be blowing hot air (from the rad) into your case. One of the benefits of watercooling, is that heat leaves the case directly through the rad, it doesn't get blown around and out with an air cooler. You'd just defeat the purpose if you used a radiator for intake airflow.

The best role for a rad, in my mind, is as a top exhaust fan. It contributes to the airflow of your case, while taking advantage of convection and radiating heat out rather than in. Though, I'm sure you know this and are just trying to make the best of a bad situation?

Sorry, I'm just a bit confused

 

[zjuventus14]

I hope I'm not misunderstanding, but are you saying that the only place for the radiator is in the front?

Unfortunately, mounting the rad as a front intake fan would be very counter productive, as you'd be blowing hot air (from the rad) into your case. One of the benefits of watercooling, is that heat leaves the case directly through the rad, it doesn't get blown around and out with an air cooler. You'd just defeat the purpose if you used a radiator for intake airflow.

The best role for a rad, in my mind, is as a top exhaust fan. It contributes to the airflow of your case, while taking advantage of convection and radiating heat out rather than in. Though, I'm sure you know this and are just trying to make the best of a bad situation?

Sorry, I'm just a bit confused

Yes, I essentially am making the best of a bad situation. I was hoping to get a new, larger case along with the radiator on my birthday. I may buy myself a new case soon with some gift money. But yes, the front is currently the only location for the radiator. So based on your reply you suggest exhaust for the radiator and intake for the front and back, although it is not optimal?

 

[DonQuixoteMC]

I don't think I was very clear in that post sorry about that

The optimal situation would be an exhaust radiator, mounted at the top of the case, with intake fans from the front. I don't want to go into positive/negative pressure or anything, so let's just ignore that.
So optimally, you would have the radiator mounted at the top as an exhaust, with two 140mm fans at the front. If there's room for the rear facing fan, might as well have a 120 to draw more air towards the rad.

But am I correct in assuming that this setup isn't possible with your case?

Also, I would use the EKWB fans on your rad. They have a higher static pressure, which should help force more air through the fins.

 

[DonQuixoteMC]

The worst case scenario would be having the rad as a front mounted intake fan. Because then you're just filling your case with hot air. You need the radiator as an exhaust. I think it would suit you to avoid the rad as an intake so much so that it would be better to have a front mounted exhaust, with intake fans on the top/back.

You might even want to try (if you have the room and enough fans) a push/pull config on the rad if you need to go this route, this should help work against the bit of resistance you'll get from convection with more airflow.

 

[zjuventus14]

I don't think I was very clear in that post sorry about that

The optimal situation would be an exhaust radiator, mounted at the top of the case, with intake fans from the front. I don't want to go into positive/negative pressure or anything, so let's just ignore that.
So optimally, you would have the radiator mounted at the top as an exhaust, with two 140mm fans at the front. If there's room for the rear facing fan, might as well have a 120 to draw more air towards the rad.

Also, I would use the EKWB fans on your rad. They have a higher static pressure, which should help force more air through the fins.

Speaking of, because of my situation, I assume still radiator exhaust in front and intake in rear and top because there is not room for the radiator on top? Also, because I would prefer positive pressure to avoid dust build up in my case, is it worth it to instead use the default fans on the radiator and use the Vardar as an intake on top, which considering the CFM of my fans would result in positive air pressure inside my case?

 

[DonQuixoteMC]

Yeah, I think that's your best bet (see my last post, for some reason I posted them separately haha)
_______________
|......+ +.............- | →
|+→ ↓ ↓............. - | →
|.........................- | →
|.........................- | →
|______________|

One (+/-) = 120mm
Two (+/-) = 140mm
Arrows show direction of flow

Obviously this beautiful render of the setup doesn't show CFM or anything, just trying to see how the fans will line up.

So if that's the configuration we're talking about, then I think you would need to double down with negative pressure and still use the EKWB fans on the rad. Even a push pull would be ideal. I'm just afraid, since you're working against convection anyway, the last thing you want is to have your one exhaust to be fairly restricted.

It's up to you of course where you end up deciding to put the fans, but that's just my two cents. If worse comes to worse, you could even test out different configs and try to see which performs best.

As for dust and positive/negative pressure, I'm not sure there's much of a real-world difference, at least not if every fan mount has a fan in it. It certainly wouldn't affect cooling as much as a stagnant airflow would.

EDIT: hahahaha I figured that would happen with my little "diagram." How tragic... Well, I'm sure we're talking about the same setup
EDIT #2: I will never try to illustrate a fan configuration again with simple text haha

 

[zjuventus14]

Yeah, I think that's your best bet (see my last post, for some reason I posted them separately haha)
_______________
|......+ +.............- | →
|+→ ↓ ↓............. - | →
|.........................- | →
|.........................- | →
|______________|

One (+/-) = 120mm
Two (+/-) = 140mm
Arrows show direction of flow

Obviously this beautiful render of the setup doesn't show CFM or anything, just trying to see how the fans will line up.

So if that's the configuration we're talking about, then I think you would need to double down with negative pressure and still use the EKWB fans on the rad. Even a push pull would be ideal. I'm just afraid, since you're working against convection anyway, the last thing you want is to have your one exhaust to be fairly restricted.

It's up to you of course where you end up deciding to put the fans, but that's just my two cents. If worse comes to worse, you could even test out different configs and try to see which performs best.

As for dust and positive/negative pressure, I'm not sure there's much of a real-world difference, at least not if every fan mount has a fan in it. It certainly wouldn't affect cooling as much as a stagnant airflow would.

EDIT: hahahaha I figured that would happen with my little "diagram." How tragic... Well, I'm sure we're talking about the same setup
EDIT #2: I will never try to illustrate a fan configuration again with simple text haha

Thanks for the help . I can't do a push-pull due to size restraints, but I can if I upgrade cases(probs will). Thank you.

 

[Anjum9694]

I hope I'm not misunderstanding, but are you saying that the only place for the radiator is in the front?

Unfortunately, mounting the rad as a front intake fan would be very counter productive, as you'd be blowing hot air (from the rad) into your case. One of the benefits of watercooling, is that heat leaves the case directly through the rad, it doesn't get blown around and out with an air cooler. You'd just defeat the purpose if you used a radiator for intake airflow.

The best role for a rad, in my mind, is as a top exhaust fan. It contributes to the airflow of your case, while taking advantage of convection and radiating heat out rather than in. Though, I'm sure you know this and are just trying to make the best of a bad situation?

Sorry, I'm just a bit confused

Just signed up to this website to say thanks. It was the perfect explanation of what I was trying to find out.