AIO Radiator - mounting with inlet/outlet at the top or bottom?

[reflux]

I've got an NZXT Kraken AIO because I wanted some fancy cooling without the hassle of a custom loop (and I got rid of all my w/c stuff years ago). When I built the PC, I mounted the radiator on the inside of the front panel with the inlet/outlet at the bottom of the rad, but everything I see an AIO in a case like mine (NZXT Source 340 Elite) the radiator seems to be mounted with intlet/outlet at the top of the rad.

Does it make any difference? Should I change the radiator orientation?

 

[MikeTimbers]

The manuals say it makes a difference but logically it shouldn't. The pump has to push the water up either the return half or up the front half.

 

[reflux]

Yeah that's what I thought. Then I thought about air bubbles potentially getting trapped in the block/pump, but if they make to my radiator in the current config they'll just stay at the top of that, which seems like the best place for them.

 

[Prozn]

In my mind (and this is most likely wrong, so don't take it as advice), having the mini-reservoir of the radiator at the top will cause a bit more head pressure and mean the pump has to work less hard to move the fluid upwards.


Edit: seemingly, head pressure isn't a thing in a closed loop, so I was mistaken

 

[LuckyBenski]

In my mind (and this is most likely wrong, so don't take it as advice), having the mini-reservoir of the radiator at the top will cause a bit more head pressure and mean the pump has to work less hard to move the fluid upwards.


Edit: seemingly, head pressure isn't a thing in a closed loop, so I was mistaken

That said, air has more capacity for compression than water so there is an element of truth in there. I doubt it'd significantly affect the system though.

 

[MikeTimbers]

You need some part of the radiator to be above the block/pump, same as for all water-cooling loops to ensure the pump is primed when it starts. A dry pump can't move anything.