Opinions on Air flow set up

[shadowr1ku]

Hello Forum!

 

So I am planning to change out my case and give my 760T to my girlfriend's brother. I am planning to get either the Define S or Enthoo Pro, quite not so sure.

 

Anyway, I am getting the Corsair H110i GT cooler *dual 140mm radiator* Would Mounting it as Front intake with a 140mm as an exhaust be enough to help airflow? Trying to go for that positive air pressure.

 

I have 3 NF-F14's so I can replace the stock fans.

 

Any questions feel free to ask, thank you!

[blackadder]

I think most rads should be exhaust so the hot air isn't pushed around your case. Mount it on top and leave the rest as stock.

[ThomasD]

There was a recent post here noting some problems with top mounting the H110 in a Define R5 - it interfered with mounting a rear 140 mm fan.  Not sure if you would have the same problem with the S, but given their similarity it could be an issue.

 

I too prefer that radiators vent heat out of the chassis - not back into it.  You can get away with rads on intake if you otherwise have lots of airflow, but I still don't like it. 

 

I'm also skeptical of fans, driving through a radiator, providing good positive pressure.

 

Given your desires I'd go with the Enthoo - top mount the radiator, and have two good 140 mm in the front, like the Cougar Vortex HDB,  or Enthoo 140 XP (both have strong SP ratings) and a stock fan in the rear.  Given the restricted flow through the radiator you might get positive pressure from that setup alone.  If not then dial back the rear fan's speed, or add a bottom intake (my recommended option - cool air coming up from the bottom does wonders for all component temps.)

[shadowr1ku]

There was a recent post here noting some problems with top mounting the H110 in a Define R5 - it interfered with mounting a rear 140 mm fan.  Not sure if you would have the same problem with the S, but given their similarity it could be an issue.

 

I too prefer that radiators vent heat out of the chassis - not back into it.  You can get away with rads on intake if you otherwise have lots of airflow, but I still don't like it. 

 

I'm also skeptical of fans, driving through a radiator, providing good positive pressure.

 

Given your desires I'd go with the Enthoo - top mount the radiator, and have two good 140 mm in the front, like the Cougar Vortex HDB,  or Enthoo 140 XP (both have strong SP ratings) and a stock fan in the rear.  Given the restricted flow through the radiator you might get positive pressure from that setup alone.  If not then dial back the rear fan's speed, or add a bottom intake (my recommended option - cool air coming up from the bottom does wonders for all component temps.)

 

Cause I heard to create Positive airflow, more intake than exhaust. My current setup now is 3 exhaust and 2 intake, 2 of them being the h100i. I am trying for figure out a set up that I can get a dual radiator and have positive airflow. Best case scenario would be 2 exhaust 2 intake

[blackadder]

Cause I heard to create Positive airflow, more intake than exhaust. My current setup now is 3 exhaust and 2 intake, 2 of them being the h100i. I am trying for figure out a set up that I can get a dual radiator and have positive airflow. Best case scenario would be 2 exhaust 2 intake

you really want as close to neutral pressure. Less dust overall.

[shadowr1ku]

you really want as close to neutral pressure. Less dust overall.

 

I will definitely do the best I can, I wish I can have more than one solved but both you and @ThomasD helped me out a bunch. Thank you guys!

[ThomasD]

Cause I heard to create Positive airflow, more intake than exhaust. My current setup now is 3 exhaust and 2 intake, 2 of them being the h100i. I am trying for figure out a set up that I can get a dual radiator and have positive airflow. Best case scenario would be 2 exhaust 2 intake

Assuming identical fans then yes, the easiest way to be positive is to have more going in than going out.  But with different sizes or types of fans then it becomes an exercise of adding up the rated numbers, then applying a bit of fudge factor/intuition, followed by real world testing and tweaking of fan speeds or overall setup.

 

The reason being that fan specs are ideal - a single fan operating in an unrestricted fashion, with no other fans affecting its performance.  Common sense should tell you that those numbers go out the window once we enter the real world.  Fans with low static pressure ratings quickly drop their volume when they encounter any sort of restriction.  High SP fans are less affected, but still do drop, and they tend to be more noisy when doing so.

 

And just to be sure we are working on the same page  - positive pressure is only of any benefit if all of the intakes are filtered.  The downside of negative pressure is that every gap in the chassis becomes an unfiltered intake.

 

Best results in terms of both dust reduction and cooling are achieved through slightly positive pressure and moving only the amount of air necessary to achieve the desired temps (moving more air than necessary only creates noise and clogs the filters quicker.)

 

If your desire is two in and two out then simply choose two quality SP type fans for the radiator, set as exhaust; and then use the exact same fans as filtered intakes, and nothing else.  If all goes well the restriction caused by the filter will not be as much as the restriction caused by the radiator, resulting in a (very) slight positive pressure.  If that fails then simply add one more intake fan.

[shadowr1ku]

Assuming identical fans then yes, the easiest way to be positive is to have more going in than going out.  But with different sizes or types of fans then it becomes an exercise of adding up the rated numbers, then applying a bit of fudge factor/intuition, followed by real world testing and tweaking of fan speeds or overall setup.

 

The reason being that fan specs are ideal - a single fan operating in an unrestricted fashion, with no other fans affecting its performance.  Common sense should tell you that those numbers go out the window once we enter the real world.  Fans with low static pressure ratings quickly drop their volume when they encounter any sort of restriction.  High SP fans are less affected, but still do drop, and they tend to be more noisy when doing so.

 

And just to be sure we are working on the same page  - positive pressure is only of any benefit if all of the intakes are filtered.  The downside of negative pressure is that every gap in the chassis becomes an unfiltered intake.

 

Best results in terms of both dust reduction and cooling are achieved through slightly positive pressure and moving only the amount of air necessary to achieve the desired temps (moving more air than necessary only creates noise and clogs the filters quicker.)

 

If your desire is two in and two out then simply choose two quality SP type fans for the radiator, set as exhaust; and then use the exact same fans as filtered intakes, and nothing else.  If all goes well the restriction caused by the filter will not be as much as the restriction caused by the radiator, resulting in a (very) slight positive pressure.  If that fails then simply add one more intake fan.

 

Right now I have 3 NF-A14's as my case fans (2 intake, 1 exhaust) and then I have my current h100i (Top mounted) which has 2 NF-F12's as exhaust. While I will change cases soonish, I wanted to figure out the best way to achieve slightly positive air pressure as I can, given that my h100i will be replaced with h110i GT.

[ThomasD]

Right now I have 3 NF-A14's as my case fans (2 intake, 1 exhaust) and then I have my current h100i (Top mounted) which has 2 NF-F12's as exhaust. While I will change cases soonish, I wanted to figure out the best way to achieve slightly positive air pressure as I can, given that my h100i will be replaced with h110i GT.

Ok, so you are effectively +1 on intake vs. outflow in chassis fans.

 

But which NF-A14s?

 

http://www.noctua.at/main.php?show=produkte&lng=en#fans

 

Once you know which one then look up it's flow rating and multiply cubic meters per hour by 0.59 to estimate flow rate in CFM.

 

The H110 is rated at a max of 113 CFM airflow.   So subtract the CFM value of the one Noctua from the 113 CFM of the Hydro, that is how much airflow you must add in order to maintain near neutral pressure when the Hydro is at max speed.  

 

Stay under that and you will be negative, go over and you will begin to go positive.

 

Then find a fan that fills the bill, preferably one with a decent static pressure.

[shadowr1ku]

Ok, so you are effectively +1 on intake vs. outflow in chassis fans.

 

But which NF-A14s?

 

http://www.noctua.at/main.php?show=produkte&lng=en#fans

 

Once you know which one then look up it's flow rating and multiply cubic meters per hour by 0.59 to estimate flow rate in CFM.

 

The H110 is rated at a max of 113 CFM airflow.   So subtract the CFM value of the one Noctua from the 113 CFM of the Hydro, that is how much airflow you must add in order to maintain near neutral pressure when the Hydro is at max speed.  

 

Stay under that and you will be negative, go over and you will begin to go positive.

 

Then find a fan that fills the bill, preferably one with a decent static pressure.

 

Sorry, forgot to mention the correct models! The case fans are PWM fans