140mm 1200 vs 120mm 1300 fan for Obsidian 550D ?

Ok I'm thinking about changing 120mm fans in my case to 140mm I want to buy Noctuas but not sure if it's worth it. Does 140mm 1200RPM will push more air and be quieter than 120mm 1300RPM? I have Obsidian 550D case and there are those dust filters with small holes in them so I need the power to push air through. So I'm not sure if slower bigger fan is in this case good idea.

The Corsair AF140 has 11 blades and pushes more air than the Corsair AF120 with 8 blades (however the stock fans are not AF series fans). Typically the larger the fan, the quieter it will be. I remember when case fans were 40mm, 60mm, 80mm, they're noisy because they're running at 2500, 2000, 1800 RPM.

The 140mm fans will push more air using less RPMs so they are better performing and generate less noise. If you're planning on replacing the two front 120mm fans I don't think those fan slots support 140mm in the 550d. You could replace those with AF120/SP120 quiet versions depending on your drive bracket configuration.

The 140mm fans will push more air using less RPMs so they are better performing and generate less noise. If you're planning on replacing the two front 120mm fans I don't think those fan slots support 140mm in the 550d. You could replace those with AF120/SP120 quiet versions depending on your drive bracket configuration.

 

I just looked at mine, the front 120mm are only 120mm no mounts for 140mm in the front. My plan for my case was to eventually upgrade the two front 120s to AF120, AF140 in front of the PSU, and AF140 rear exhaust. I don't plan on installing fans or radiators on the top or side.