120mm radiators

[Gnoad]

So I've been looking around dangerden for a watercooling system, and thought I would get a dual 80mm fan radiator that I could mount in my case. Out of curiousity, I looked at the 120mm fan radiator, and even though Its just 1 120 compared to 2 80, It had better heat dissapation numbers. I thought this was odd, and am wondering if anyone can tell me that yes, 1 120mm radiator is better than a dual 80mm radiator. I may just end up getting a dual 120mm and hacking up my case with my dremel anyways though, seeing how much better they seem to be.

 

[CharlesMcKinney]

I am in no way an expert on watercooling, but geometrically, it makes sense:

1 120mm radiator has more surface area than 2 80mm radiators.

120mm^2 = 14400mm surface area

2 * 80mm^2 = 12800mm surface area

More surface area = better cooling. How much better I have no idea. I was actually pondering this too, as if I wanted to put a 120mm rad in my case I'd have to cut a blowhole (which I may end up doing even if I stick with air).

 

[Gnoad]

Hmm, I didn't think of it that way. I just thought 80*2=160, and 160>120. Makes sense though.

 

[iamtrout]

Yes, the outside surface area is larger on a 120mm, but you also have to think about the total fin surface area, which the 120mm has a LOT more of than two 80mm's. Also keep in mind that a typical "120mm" radiator is actually larger than a 120mm fan, hence the need for a shroud. Most "120mm" radiators are actually about 140mm across, while 80mm radiators are just that, 80mm across.

 

[CharlesMcKinney]

^^ what he said. I was just trying to make an easy to understand comparison. I neglected to mention the inner workings, more because of laziness. 😛