Heat Sink Orientation

I have some Pete Millett filament regulators and I'm evaluating how best to orient the boards/heatsinks?
Assume the heatsinks will be the same size and some ventilation holes will be drilled above the heatsinks. I think the boards will benefit from not being baked in the heat but am I worrying about nothing? The blue surface is the bottom of the top plate and is 0.125" thick,
PXL_20220707_180012653.jpg
 
Heat rises even in metal, the device goes on the bottom of the heat sink always, fins vertical or on top, the should never be oriented horizontally unless assisted by a fan or if it is more than big enough to dissipate whatever amount heat is at question.
I have done tests like this and you would be surprised at the results of how much just a little tiny bit of air movement can make on the delta temp of a heatsink of anysize.
By the way 3 is the best orientation. 😉

FWIW
jer 🙂
 
Hello, I am using one of Pete's Fil-Reg boards to feed the filaments of six 6922's.

The heatsink is oriented vertically and rises through a hole punched in the top plate. With one 55mm heatsink it was getting too hot for my liking. If I remember correctly, I was measuring about 160F at the very bottom of the heatsink, so the device temperature would have been higher. I smeared some thermal paste on another 55mm heatsink and stacked it on top. That dropped my temperature to around 130F and I can live with that.

Dan
 
Hello, I am using one of Pete's Fil-Reg boards to feed the filaments of six 6922's.

The heatsink is oriented vertically and rises through a hole punched in the top plate. With one 55mm heatsink it was getting too hot for my liking. If I remember correctly, I was measuring about 160F at the very bottom of the heatsink, so the device temperature would have been higher. I smeared some thermal paste on another 55mm heatsink and stacked it on top. That dropped my temperature to around 130F and I can live with that.

Dan
That's a lot of current! Gives me confidence that dividing my 2.5A draw between two boards will be adequate.
Thanks for the information!