Multiple 80mm VS single 120mm performance

[ZRock]

So I stumbled across a free case, YAY MODDING!
Looking to dremel some new case fan locations on the side and maybe top panels, but I had a question...
In the intake in the front, I have holes to mount 4x80mm fans, or a single 120mm fan in the center of it all.
In the exhaust, I have room for 2x80mm 1 above the other, or again, a single 120mm fan. Any suggestions on how my temps would change if I just went with the 2 120's vs the 6 80mms?

 

[trents]

As long as the total CFM is the same its a wash. Two 80 mm fans pushing 40 cfm apiece would be the equivalent of one 120 mm fan pushing 80 cfm. The noise is the other issue. In my experience, two fans making 25 db of noise each will be quieter than 1 fan making 35 db of noise. CFM is cumulative; noise is not because there is a threshold factor with noise.

 

[ZRock]

In an attempt to avoid a new topic then, any recommendations for the 80mm/120mm fans?
http://www.newegg.com/Product/Product.aspx?Item=N82E16835168006 are cheap, high cfm, fairly low noise... what would be wrong with these when I see GT's going for $25+

And for 80mm?
Having a hard time finding a decent competitor.

 

[trents]

Reading reviews are helpful in choosing fans but keep in mind people's individual hearing sensitivity plays a major factor with regard to noise. If the fans will be oriented so as to push air parallel to the ground you will be better off getting "two ball bearing" fans as the "sleeve bearing" fans and "rifle bearings" don't last as long in that position, 50,000 hr. rating vs. 30,000. If cost is important, go to ebay and search for Yate Loon fans. They are real cheap but have a rep for being reliable sleeve bearing fans of reasonably good quality and for the price can be replaced as needed and you still come out ahead. They come in low, medium and high speeds. I'm running them myself and when the bearings get dry I just peel the lable back, remove the rubber plug put a drop or two of 3-in-1 oil in and they go for a few more months of 24/7 use.

 

[Psycogeec]

what he said ^ , sleeve bearings are for automotive water pumps, and we all know how well that worked out
with 120s and the low RPM the lifetime of them is better for sure. but Dual ball fans of good quality i have never had to replace ever. they are a bit quieter too. they have a lot of cool names for cruddy bearing fans and thier lubrication systems. if your fans are going to be going non-stop for years, none of those names help do that

 

[trents]

Actually, from everything I've read sleeve bearings are quieter than ball bearings, until they get dry that is. But I have some hearing loss and I can't tell the difference between the two when other things are equal.