Static fan comparison on a Air cooler help.

[Molesy]

Hi guys,

 

A question about SP fans with a tower cooler. In this case I would like to use the Dark Rock 4 as an example. now in principle we like to get higher SP fans for liquid coolers due to the fin density and people like to use the Corsair ML and Noctua AF fans for their high SP. so on a Dark Rock 4 the default fan comes with approx 1.05 SP and 55CFM, why would i not change it to a Corsair  ML or a Noctua AF that have closer to 3.0 SP and 90CFM. would that not make the Dark rock perform better ? assuming noise is not an issue.  wont the better SP of these fans allow the air move quicker through the heat sink taking the heat away. 

 

Thanks.

[Eumel2]

Tldr: The cooling power is based on the fin area and not so much on the airflow given you get enough of it.

 

Heat transfer is based on temperature difference, so the maximum you can achieve is (fin temps)-(ambient temp) and it gets reduce the more already warmed up air passes over the fins (fin temps)-(air temp). When you get enough airflow the air temp is only gonna rise a couple degrees over ambient so the temperature difference will change only by a few percent as in 80°C-20°C to 80°C-23°C. That means that enough airflow to keep the air temperature in the cooler sufficently low will barely profit from more airflow.

 

[Molesy]

4 minutes ago, Eumel2 said:

Tldr: The cooling power is based on the fin area and not so much on the airflow given you get enough of it.

 

Heat transfer is based on temperature difference, so the maximum you can achieve is (fin temps)-(ambient temp) and it gets reduce the more already warmed up air passes over the fins (fin temps)-(air temp). When you get enough airflow the air temp is only gonna rise a couple degrees over ambient so the temperature difference will change only by a few percent as in 80°C-20°C to 80°C-23°C. That means that enough airflow to keep the air temperature in the cooler sufficently low will barely profit from more airflow.

 

i see. but i guess you need the SP to push the air through the denser fin array of a AIO radiator. so with air cooler like the Dark Rock 4 are they also not considered dense ? do we not need the SP to push the air through all the fins ?

[Eumel2]

Be quiet will have done the math on that and they know exactly what they put in the cooler. Radiators are denser especially thick ones and you never go wrong with advising noctua just because more airflow might not help but definetly never hurts

 

They will operate in a setting that saturates the airflow so it will be fine. 

[Molesy]

Just now, Eumel2 said:

Be quiet will have done the math on that and they know exactly what they put in the cooler. Radiators are denser especially thick ones and you never go wrong with advising noctua just because more airflow might not help but definetly never hurts

 

They will operate in a setting that saturates the airflow so it will be fine. 

I see. yea i personally go for the ML instead of the Noctua as i prefer the looks and to get the Notctua Industrial is way to $$ here. though the redux is a nice compromise. though sold out a lot haha.  

 

But good to know so i dont need to change the fans. I guess now i just have to decide between my air coolers for the i9 9900K with no OC for the next 1 year but will be at 100% load for extended periods of time. so was thinking of the Dark Rock 4 or the Dark Rock TF as the TF would blow air on the VRM's as well and you get the extra 20W cooling capacity from the DR4 as apparently the 9900K at all core turbo can produce 210W of heat. so much higher than the websites list. So misleading.  

[Eumel2]

This is kind of an OC though

 

But yes if you plan on giving it as much power as it can take als grab the beefiest cooler you can find

[WoodenMarker]

Yes, it'll probably perform better if you put ML140's or NF-A14's on it but it'll also be noisier.

The reason why it's not the best option is that you could've gotten a better cooler to begin with instead.