Fan direction on heatsink

yosim

Well-Known Member
hi, sorry i couldnt turn up any results for this with the search im sure it has been asked before

but anyway, should the fan blow air away from the heatsink or towards? or maybe doesnt matter?

thanks
 

robincnn

Well-Known Member
I think @robincnn had showed some tests where the heat convection rising naturally on pin fins and you use the fan to pull air up from the cob and past the pins.maybe it was someone else
For passive the hot air streams rise up.
For active cooling best to blow air on heastink. For pin heatsinks it can be from top or side. i would prefer top.

Rule says coolest part (air) must be near hottest part of heatsink (base palte) or something like that.
If you pull air from top of pin heatsink then the it will not pull air from hottest part. It will pull from around top pins.
If you blow air down the pins it will reach the hottest part ..base plate
 
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