Radiator fans, what's important?

[Quivz]

I assume static pressure since the air needs to be forced into a confined space. I don't have my cooler yet, but to get my rgb uniform i might want to change the fans out. The difference in static pressure is around 0.15 mmh2o lower compared to the ones included with cooler. Is it that big a deal? Or will the fans just run faster and longer to dissipate the radiator heat.

 

Also what about pushing through vs pulling air through a radiator. My instinct says pushing should be better but i got a B- in fluid dynamics. I want the fans mounted up against the case for better unicorn barf visibility, but that either means the fans will have to pull the air through the rad, or heat up my case insides feeding my graphics card hot air... [okay this is sort of addressed in one of the stickies, but pulling in air vs pushing out air i could still use some info on].

 

Sound is less of a factor for me, although its got to be quieter than the amd wraith stock cooler.

Edited February 24, 2020 by Quivz
found some info in stickies

[Niklos]

As far as I know, the max mmh2o is at the max speed of the fan.

So let say that you have two fans :

 1) 60dB at full speed which is 2000RPM, that make a pressure of 1 mmh2o (fan n°1)

 2) 70dB at full speed which is 3000RPM, that make a pressure of 1.5 mmh2o (fan n°2)

So the second one makes more pressure.

 

But now, let's say that 70db is to much and you want your fan to make only 60dB so you have :

 

 1) 60dB at full speed which is 2000RPM, that make a pressure of 1 mmh2o (fan n°1)

 2) 60dB at 66% speed which is 2000RPM, that make a pressure of 0.8 mmh2o (fan n°2)

 

So fan n°1 is better @60dB than fan n°2 whereas fan n°2 is making more pressure @100%.

[Quivz]

Er yeah... So was i right about static pressure being more important than airflow?

 

I can do the numbers, but i need to know more about how the rad works and whats going to hinder it. Like pulling air through it vs pushing air through it. Is a lower static pressure going to work or are radiators built around a certain set of numbers and does using fans with different numbers not work at all? Should i push colder outside air across the rad, but then vent that warmed air into the case, or push air already in the case warmed by gpu and other passively cooled stuff across the rad and out of the case.

[alyen]

 

4 hours ago, Quivz said:

Also what about pushing through vs pulling air through a radiator.

Pushing air onto the radiator seems to work better than pull. It's more noticeable at lower fan RPM. The typical AIO radiator is 28mm so if you favor doing it another way for RGB aesthetics it may not be significantly different. At higher fan RPM it can be the same.

 

 

 

5 hours ago, Quivz said:

I want the fans mounted up against the case for better unicorn barf visibility, but that either means the fans will have to pull the air through the rad, or heat up my case insides feeding my graphics card hot air...

Should i push colder outside air across the rad, but then vent that warmed air into the case, or push air already in the case warmed by gpu and other passively cooled stuff across the rad and out of the case.

 

For my components with a radiator mounted on the front of the case, the GPU seems slightly hotter but not by much for my RTX 2060. It helps the GPU temp to have a fan mounted on the bottom of the case. Some cases with a PSU shroud that extends too far towards the front does seem give higher GPU temps. I don't play any intensive games that stress the GPU that it ever throttles. I had slightly cooler GPU temps in a configuration with the 360 radiator on top inside of the Fractal R5 compared to a 360 radiator in the front of a Deep Cool E-Shield that has no PSU shroud. And with 360 radiator mounted on the front of a Deep Cool Matrexx 55 Mesh the GPU was hotter by 2 C compared to no E-Shield case that has no PSU shroud. 360 Radiaot in every setup I've tried always had slightly cooler results than being on the top of the case.

 

If you choose a good airflow case, a good 280/360 AIO and motherboard that supports 4-5 fans with 0-100 RPM you should have enough temperature headroom to work with some RGB aesthetics and being quiet. Temperatures can be more difficult to keep down if you live in a environment where its hotter, doing some extreme overclocking or cram components inside a small case with a single fan radiator. 

[AngryBeaver]

41 minutes ago, alyen said:

Pushing air onto the radiator seems to work better than pull. It's more noticeable at lower fan RPM. The typical AIO radiator is 28mm so if you favor doing it another way for RGB aesthetics it may not be significantly different. At higher fan RPM it can be the same.

There has been plenty of research done on this. There is no discernable difference between pushing or pulling. 

[VersuS]

On the push pull thing...
Fully agree with AngryBeaver in the overwhelming majority of scenarios, (case design bares this stuff in mind), but in an environment where airflow is impacted by it's surroundings one could be more beneficial over all than the other... 99.999% chance this wont affect you either way unless you're doing something pretty out the norm, but...
Air being pulled into a fan is far more linear and less turbulent than air leaving a fan. As it's dragged in its nicely lined up into a funnel, then when it hits the blades its scattered (could describe this better, but I'm sure you get me). The same ammount of air is displaced and the fans are in contact with the radiator so the only points it makes any difference for is how the air is drawn in and expelled. If you're building in an odd enclosure one or the other could be more beneficial depending on obstructions to the path of the air.
Most of the time I'd go for a push config out of laziness though... radiators are a pain in the ass to clean so the more dust the fan can catch the better imo.

 

[Quivz]

6 hours ago, VersuS said:

Most of the time I'd go for a push config out of laziness though... radiators are a pain in the ass to clean so the more dust the fan can catch the better imo.

Thanks for the info. It does actually help me visualise better whats happening and how its going to affect things, but the dust catching decided it for me. Push, with the radiator up against the case. The RGB might not be visible from above the case like that, but i've got this glorious big tempered glass window that i might as well use....