2 x 240mm radiators, 1 in front, 1 up top.

[JamesyFTS]

If I have a 240mm radiator in the front of my case set to intake, should my 240mm radiator on the top of my case be set to exhaust or intake? It will cool better bringing in the cooler air from the outside but I only have a single 140mm fan as an exhaust if they are both set to intake.

 

[Jwpanz]

You should set them both for intake. Cool air will be taken in and the single rear exhaust will push air out. This is known as positive air pressure cooling. It's usually best to take take cool air from outside of the case to blow over the hottest portions of your setup (in this case, the two radiators). This article is a little old but the concept holds to this day: https://rog.asus.com/articles/overclocking/positive-or-negative-pressure-cooling/

 

[Dragos Manea]

You should set them both for intake. Cool air will be taken in and the single rear exhaust will push air out. This is known as positive air pressure cooling. It's usually best to take take cool air from outside of the case to blow over the hottest portions of your setup (in this case, the two radiators). This article is a little old but the concept holds to this day: https://rog.asus.com/articles/overclocking/positive-or-negative-pressure-cooling/

Did you read what you posted, you did not understand what he said in that article
" Conclusions: With everything pushing inwards except the H50 exhausting, this provides the best cooling setup."
This means that the radiator should exhaust and it is the best way. Lots of fans to bring cool air inside and create positive presure and the radiator to exhaust all the heat outside.

EDIT: OP, best thing is to set all radiator to exhaust, if you cannot do that, make at least one exhaust and 1 intake and be sure to have lots of fans to bring cool air inside and push hot air outside because the radiator mounted as intake will fill your case with hot air.
Tell us more details to be able to help you, components, case.....??

 

[JamesyFTS]

You should set them both for intake. Cool air will be taken in and the single rear exhaust will push air out. This is known as positive air pressure cooling. It's usually best to take take cool air from outside of the case to blow over the hottest portions of your setup (in this case, the two radiators). This article is a little old but the concept holds to this day: https://rog.asus.com/articles/overclocking/positive-or-negative-pressure-cooling/

Did you read what you posted, you did not understand what he said in that article
" Conclusions: With everything pushing inwards except the H50 exhausting, this provides the best cooling setup."
This means that the radiator should exhaust and it is the best way. Lots of fans to bring cool air inside and create positive presure and the radiator to exhaust all the heat outside.

EDIT: OP, best thing is to set all radiator to exhaust, if you cannot do that, make at least one exhaust and 1 intake and be sure to have lots of fans to bring cool air inside and push hot air outside because the radiator mounted as intake will fill your case with hot air.
Tell us more details to be able to help you, components, case.....??

I've got the fractal design define r6 case, i7 8086k cpu, gigabyte z370 aorus ultra m/board, 16gb gigbyte rgb 3200mhz RAM and an asus rog strix gtx 1080 ti. The main reason I asked the question is that I'm installing my first custom watercooling loop and I've done a lot of research about it but the airflow direction regarding having a top and front mounted radtiator is something that I cannot find a concrete answer on.

 

[Jwpanz]

You should set them both for intake. Cool air will be taken in and the single rear exhaust will push air out. This is known as positive air pressure cooling. It's usually best to take take cool air from outside of the case to blow over the hottest portions of your setup (in this case, the two radiators). This article is a little old but the concept holds to this day: https://rog.asus.com/articles/overclocking/positive-or-negative-pressure-cooling/

Did you read what you posted, you did not understand what he said in that article
" Conclusions: With everything pushing inwards except the H50 exhausting, this provides the best cooling setup."
This means that the radiator should exhaust and it is the best way. Lots of fans to bring cool air inside and create positive presure and the radiator to exhaust all the heat outside.

EDIT: OP, best thing is to set all radiator to exhaust, if you cannot do that, make at least one exhaust and 1 intake and be sure to have lots of fans to bring cool air inside and push hot air outside because the radiator mounted as intake will fill your case with hot air.

I read it. The article uses only a single radiator. In the OP he has two 240mm AIO's. If you set them both to exhaust then you're pulling air from the single fan in the rear and the gaps in the case as well as the heated air from the GPU. It makes more sense to pull fresh, cool air from outside of the case inside of it and to havce their air pushed out by the rear exhaust fan and the gaps in the case.

Also, setting them to exhaust means dust is going to be pulled in through the gaps of the case causing it to build up faster than it would being pulled through filtered mounting points. And it would not fill the case with hot air as long as there is exhaust. Besides, having two radiators means both the CPU and GPU are being water cooled. Nothing inside of the case is using an air cooler to cool components.

All in all, the temperature differences between both intake, both outtake, or one intake and one outtake probably won't vary much. Perhaps by a few degrees. The main issue here is how to best orient two radiators. In my opinion, pulling cooler air in and creating a positive air pressure within to case and having it all exhausted by the rear fan and gaps in the case is better for preventing dust build-up.

 

[Dragos Manea]

Ok, i would do like this:
Top radaitor exhaust, front radiator intake, rear fan exhaust and buy 2 more fans mount on bottom and use them as intake. This is the best set-up you can get. Also you have positive air presure in this configuration.

Also in your configuration you can do a 360mm top exhaust and 120mm radiator rear exhaust then 3 fans front intake and 2 fans bottom intake.Also you have postive air presure in this case.

EDIT: To have an general view on this this is my build https://pcpartpicker.com/b/cWmqqs

 

[JamesyFTS]

Ok, i would do like this:
Top radaitor exhaust, front radiator intake, rear fan exhaust and buy 2 more fans mount on bottom and use them as intake. This is the best set-up you can get. Also you have positive air presure in this configuration.

Also in your configuration you can do a 360mm top exhaust and 120mm radiator rear exhaust then 3 fans front intake and 2 fans bottom intake.Also you have postive air presure in this case.

EDIT: To have an general view on this this is my build https://pcpartpicker.com/b/cWmqqs

That makes a lot of sense and I have some spare fans to use as extra intake fans. When I've got it all put together I'll post a pic and description, I would appreciate it if you let me know what you think about it. Thanks!

 

[Dragos Manea]

Which one, 360mm rad and 120mm rad or 2x240mm rad?
Radiator space is the same 240+240=480 or 360+120=480 so which one you choose is the same, has the same cooling power in total. Advantage of the 360+120 is that you dump all the heat outside the case and not inside.

 

[JamesyFTS]

This is what I've got setup, see image for airflow direction. Temps are good considering the 1080 ti and i7 8086k are both overclocked to just about as good as I can get them stable (I'm not an overclocking expert). CPU max temp under load has been 70*C and the GPU doesn't even reach 50*C. The loop order is as follows:
Pump/res - front radiator - CPU - top radiator - GPU - pump/res.

Thanks to everyone who replied to my OP.

 

[Dragos Manea]

That is nice!

 

[JamesyFTS]

That is nice!

Thanks, and thank you for your help! Sometimes a little reassurance goes a long way.