Quote:

Originally Posted by BrjSan

Was wondering since air flow has no major impact if water cooling

Who told you that? You still have to balance the airflow through the case.

Both rads blowing into the case will
1.) Heat up the case by blowing all the heat they remove right back into it.
2.) cause the fans on the rads to be working against whatever intake fan(s) you have since they will trying to push more CFM into the case than the exhaust is taking out.

You need to read about P-Q curves

 

Quote:

Originally Posted by BrjSan

Hey floks,

Was wondering since air flow has no major impact if water cooling - correct me if am wrong - is it ok to configure upper 420 and bottom 480 rads both intakes on 900D.

Luckily computer cases arent enclosed tubes with a metal plate at the end, they are wide open spaces with lots of cracks and crevices for airflow to escape. What your setting up with your fans is positive pressure and generally the recommended airflow for cases, so you should he fine setting it up that way, not to mention there are lots of 900Ds out there set up like this.

 

You really want to balance intake with exhaust. Your total net airflow is only going to be about equal to the lesser of the intake or the exhaust. There are plenty of little openings for air to flow through to balance it out but having fans work against each other will significantly diminish your cooling capability. Having the fans fight each other might work well enough to get the job done, but the setup could work much better with the fans working together.

 

I have 2x280 rads, both as intake, and one fan in the rear as exhaust. It works great. Best temps of any config i have tried.

 

Quote:

Originally Posted by kl6mk6

I have 2x280 rads, both as intake, and one fan in the rear as exhaust. It works great. Best temps of any config i have tried.

What fans are you using?

 

Quote:

Originally Posted by billbartuska

What fans are you using?

I'm using low fpi rads with enemax tb silence low speed fans in push/pull with some of them set at 75% voltage. My pc is whisper quiet under even the heaviest of gaming, benchmarks, and stress tests. ~10c delta at 550watts (660w from the wall). All my components should be in my sig rig.

 

Quote:

Originally Posted by billbartuska

Who told you that? You still have to balance the airflow through the case.

Both rads blowing into the case will
1.) Heat up the case by blowing all the heat they remove right back into it.
2.) cause the fans on the rads to be working against whatever intake fan(s) you have since they will trying to push more CFM into the case than the exhaust is taking out.

You need to read about P-Q curves

I did not understand number 2, sorry but English is not my first language. the fans on the rad are the same intake fans, i have fans only on the bottom rad and the top/ceiling rad.
Quote:

Originally Posted by Radnad

Luckily computer cases arent enclosed tubes with a metal plate at the end, they are wide open spaces with lots of cracks and crevices for airflow to escape. What your setting up with your fans is positive pressure and generally the recommended airflow for cases, so you should he fine setting it up that way, not to mention there are lots of 900Ds out there set up like this.

Any build log links?? photos?? would be appreciated.
Quote:

Originally Posted by Fuzzywinks

You really want to balance intake with exhaust. Your total net airflow is only going to be about equal to the lesser of the intake or the exhaust. There are plenty of little openings for air to flow through to balance it out but having fans work against each other will significantly diminish your cooling capability. Having the fans fight each other might work well enough to get the job done, but the setup could work much better with the fans working together.

Agree, mmmmm even if you are water cooling? Does the balance really matters a lot.

Quote:

Originally Posted by kl6mk6

I'm using low fpi rads with enemax tb silence low speed fans in push/pull with some of them set at 75% voltage. My pc is whisper quiet under even the heaviest of gaming, benchmarks, and stress tests. ~10c delta at 550watts (660w from the wall). All my components should be in my sig rig.

Since you have such setup, then:

- How are you positioning the rads ... photo please if u have, would like to see the setup, since i could not visualize how u put the rads.
- 10c delta of what, u mean difference between idle and load, or, before ending up with such rad setups ?

 

Quote:

Originally Posted by BrjSan

- How are you positioning the rads ... photo please if u have, would like to see the setup, since i could not visualize how u put the rads.
- 10c delta of what, u mean difference between idle and load, or, before ending up with such rad setups ?

Delta-t is the difference between your water temperature and ambient air temperature at a given heat load after the temperatures equalize (after 15-20 min). So my fans pulling ambient air over the radiators let the water get ~10C above the ambient air while I am stressing my CPU and GPUs (550W of heat) for 15+ min. It's a good number to shoot for while planning your setup. The more rads and higher pressure fans, the cooler your water and lower your delta-t under load will be in theory.

Here is a more recent picture of my setup it's an Air 540. I had to put the fans on the outside of the case to get them to fit in push/pull config.




Edit: My motherboard is a x99 now, but the layout is the same as the pictures.