Single-fan parallel vs dual-fan parallel vs dual-fan perpendicular heatsinks. Which dumps the least hot air into the case?

[himmatsj]

Ok guys, between the three options above, I would like to know, which design would dump the least amount/% of hot air back into the case? Which design would offer the best cooling? Which design would offer the best of both worlds?



I ask because I don't have a good case, so I need to know which design dumps the least air, but at the same time offers decent cooling. Assume the single-fan model is 6.7-inch and the dual-fan models are 8-inches long. Also, assuming similar quality of heatsinks/metals/fans are used, which would edge out?

 

[USAFRet]

The question asked is not answerable in isolation.
What heat sink?
What CPU?
What case?

Oh, and any CPU cooler that transfers less 'heat' into the case...guess where that heat stays? In the CPU.

 

[JackNaylorPE]

All the same. The laws of conservation of energy demand that a heat sink produces the same amount of heat no matter which way you blow it.

There are four issues here:


1. How fast the heat sink moves heat from the CPU. All other things being equal, bigger = better

2. How fast you move the heat from the heat sink to the case interior. All things being equal, more fans will remove heat faster.

3. How you mount the cooler. Most coolers work 2-3C better with fans blowing towards the rear of the case.

4. How fast you move the air from the case interior. This is entirely dependent on case fans.

 

[coozie7]

@ Himmatsj: Are you talking about a CPU or graphics card cooler, mate?

 

[greens]

We can’t really answer this question because your premise is wrong

All heatsinks dump identical amounts of heat into the case if they are working, that is just physics.
Say you test each cooler, and get CPU temps of 40 for each one… wouldn’t that mean they were all dumping identical heat into the case? It would.

So then, the only way a heatsink could dump less heat into the case is if the CPU wasn’t getting its heat taken away, so you’d be looking at a CPU temp of 50 or 60. Your case ambient temp would be cooler, but your CPU would be hotter.

Overall energy is conserved, and TDP is always the same regardless of what bits of copper or aluminum you have between the wall outlet and the hot air coming out of the case.