heatsink estimation

[elizard]

estimated heatsink rating:

can someone help me estimate the heatsink rating on this particular heatsink?

the dimensions are 5" by 2 1/4", and can be of any length.


the best rating that i was able to come up with so far was 0.6C/W by comparing it to a thermalloy (i think) extrusion, so i just want to confirm this.

Thank You

 

[elizard]

btw, the 0.6C/W rating was for a 12" long heatsink

 

[elizard]

nevermind, found it again
http://www.aavidthermalloy.com/bin/exdisp.pl?Pnum=67170&LengthUnits=in&ExLength=3&airflow=57.2

i think that looks about the same

 

[elizard]

now, my question, they have a .63C/W rating at 12" and .73C/W at 9"
can i use 6 of the 12" ones, or 8 of 9" ones for an aleph 5 (both channels, 3/4 per channel)

 

[LaMa]

When you use 3 pieces of 12" the total rating for one channel is about (0.63 [C/W]) /3=0.21 [C/W]

When you use 4 pcs of 9" it will be about (0.73 [C/W]) /4 =0.1825 [C/W]

So when the heatsink is too high (with the finces directed vertically) it is less effective.