"Hegg, Jerry" wrote:
>
> When setting up this formula on my Excel spreadsheet,
> I calculated and also found in an engineering formula book that:
> One square inch is 0.00064 square meters, not 0.0064 meters (.0254 m
> x .0254m).
>
> Jerry A. Hegg
> Manager, Package Design
> Lockheed Martin Missiles & Fire Control - Dallas
> (972) 603-7470

Well, not to belabour all this, but it is getting
interesting.  Since, A is off by a factor of 10,
(my mistake), that makes it about 1/3 W for a
square inch instead of th 3 watts I had said
previously.  This gives ranges of

Q              for Still Air
0.29           h = 23
0.36           h = 28

               for Turbulent Air
1.0            h = 85
1.4            h = 113

So, I think the way I'm supposed to interpret
all this is - say my processor puts out about
35 Watts.  The heatsink for the processor with
two fans right on it gives say an h = 113.
That means I need a heatsink with an area of

A = Q/(h*deltaT) ~ 0.0154 sq. meters = 24 sq. in.

Well, maybe.  Seems like there's a lot of fudging
that has to be done to fine tune this.
Thanks for the correction.

And that's my two cents ...       - Doug