Heat sink Area

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Heat sink Area

Postby frank carcia » Wed Oct 15, 2003 8:56 pm

The heat sink is a good chassis but how do you know if it is sized correctly. Take a 1 square inch of surface Dissipate 1 watt.
There is a simple formula 130 degrees C / Watt /Square inch
This means a square inch of heat sink will raise 130 degrees when absorbing 1 watt of power. Take a heat sink with fins and look at the area
including both sides of the fins. Say it is 1000 total square inches and you want to dissipate 100 watts. The heat sink will riase 13 degrees C.
The position of the fins will effect the real temperature rise but this is a good place to start. Vertical fins with a vertical mounting surface is the
most efficient heat sink. Vertical fins pointing up is the second best.
That is my choice for mounting hot parts so heat raises from the deck below. Still the vertical /vertical sets up better natural air flow.
frank carcia
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Location: Enfield Ct. / Niantic Ct.

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