Need help with fan decision!

[hito]

I would like to know if you guys think this would be a okay fan setup...

I currently have a MagiK fan that came with my Enlight 7237 for intake and a standard sunon for exhaust and the psu fan for exhaust(also using a MagiK fan). I recently decided to install grommets for the case, and noticed that my case is rather dusty with only two months of running 24/7. I assume it is because of the negative pressure in the case, and the fact that my intake fan doesnt have a filter. My intake doesn't have a filter because it uses the fan holder which came with my Enlight 7237 for a 80mm fan. I am now planning on changing the fans. Here are the fans that I have in mind.

Sanyo Denki(55.1cfm, 36dBa) - intake
Panaflo 80 L1A(24cfm, 21dBa) - exhaust

I have a question about the noise factor however. I will be installing a noiser fan for the intake than what I have currently. However I will be installing a much quieter fan for the exhaust than what I have right now(sunon 32dBa). Will the noise be lower than what it is now? Or will it be louder since the higher noise producer is closer to me. All this is when I am sitting down at my computer. (Tower is on top of the desk, right next to monitor)


- hito

 

[hito]

^bump

 

[lifeguard1999]

Your question is:

"Will the noise be lower than what it is now?"

Yet you do not tell the noise rating on the current MagiK fan. So without knowing, it is impossible to answer the question.

The best setup for a case is where the fans are balanced on intake/outflow. That setup is difficult to achieve exactly because the fans are rated by their manufacturer under ideal conditions with no obstructions. In reality, fan guards, filters, etc. are obstructions causing degraded performance. Still, having two fans that are roughly balanced is best.

In your setup, you will have the Sanyo 55 CFM intake fan without a filter. This will pressurize the case, and you will not get 55 CFM out of the fan. Assuming no obstructions for the outflow fan and a leaky case, the higher case pressure will probably cause it to perform better (faster revolutions) and have a slightly higher noise than its rating. You intake fan will probably (and this is a guess) get ~40CFM and still be noisy (36 dBA).

Steps that I take are:
1. Change your air filter in your AC/heater to a better brand. This gets the dust out of the air.
2. Balance your fans.
3. If concerned about noise, go with low noise fans throughout the case.

 

[hito]

Oh, I seemed to have forgot to mention the noise of the fan. I would rate the fan at 30dBa. I currently have mesh filters for the exhaust fan, and am planning on getting a filter for the intake fan aswell. Not sure if it will be the open foam cell or the mesh aswell.

- hito