What size case fan?

[mlg]

How is the noise from a 120mm case fan? I read somewhere that the bigger fan can move more air for less noise. I live without AC, and I'm intersted in an AMD system and flight simulators, so case-cooling will be important to me. Since listening to music while I surf is also important, I'll care about noise too.
I've noticed that the Enlight cases use 80mm fans, while Fong Kai and Antec have some room for larger ones.
What about power consumption from the big fans?

 

[ericd]

Basically as you move up in size of fans...they get louder. But it is also true that if you have specific requirments as far as amount of air pushed by a fan it can be done with less noise. I think examples might help. For my first statement we will look at the Panaflo L1A series.

60mm L1A : 24 dBA
80mm L1A : 21 dBA
92mm L1A : 27 dBA
120mm L1A: 30 dBA

now I know that there is a contradiction here between what I said previously and what is illustrated here. The reason for this is the fact that the amount of room for air to move through is proportionally smaller on a 60mm fan than on 80mm and above. This means that to get decent amounts of airflow the fan has to spin faster and therefor create more noise.

To illustrate my second statement we will look at the specs of two fans which move ~40 CFM: the Panaflo H1A 80mm and the Panaflo L1A 92mm.

The Panaflo H1A 80mm produces ~39.6 CFM but creates ~32 dBA of noise in the process.
The Panaflo L1A 92mm produces ~42.7 CFM but only creates ~27 dBA of noise in the process.

So you can see that at about the same CFM a larger fan will be quieter.

In conclusion if you are looking for the quietest case you can get you need to use 80mm. If you are looking for the max amount of cooling possible use while still keeping it as quiet as possible use 120mm fans.

Hope this helps.

Eric

To answer the power consumption issue. A 120mm L1A draws appoximatly 2.5 times the wattage of the 80mm. But even the 120mm only draws 2.16 watts so you could have quite a few 120mm fans before it would become a concern.

 

[mlg]

Thanks, that's quite helpful. Does the brand of fan make much difference? I see that Directron wants $24 to include a panaflo 120mm with a Fong Kai 320, which is a BIT on my budget, especially since They'll want $30-50 for shipping-which those 'system guides' always leave out of their costs That's my first choice for a case, but they don't have all of my other first-choices, and since they're in Texas and I'm in NY, shipping costs are likely to be problematic

 

[ericd]

Brand of fan makes a HUGE difference. Well actually not.....well kind of. Fans of different brands but the same specs will perform nearly identically. I only suggest Panaflo because they are renowned for the efficiency and quietness. However you could use Sunon or any other brand you wish...I think you will find that you won't find any fans cheaper than the Panaflos that are as quiet. For cheaper Panaflos and great service go here.

Eric

edit: the standard way that caseetc.com sells Panaflos is bare wire. If you look in the "Tailed Fans" section you will find them with molex connectors already attached, they are currently out of stock on the tailed variety however.

 

[mlg]

Good Morning to you too Like a chat-room here Couldn't you sleep either?

 

[ericd]

Actually I have to be awake.....freakin work. Oh well at least I'm doing something productive with my time at the office......just don't tell my boss

Eric