westend wrote:
Hey Gordon,
From my experience with heat dissipation, I don't think you're going to get much better dissipation by increasing the dimensions of the aluminum plate. Heat from devices like this transfer from conductive to convective in a fairly small locality. You may get better reflectivity, though.
Nice polish job on that block!
You are correct, increasing the size of the plate alone does not help much with convective cooling. My goal is to increase the thermal mass. If the LEDs are heaters, running on a fixed power, the more mass they have to cool, the less heat will be "trapped" inside them. Entropy of the mass is always working to cool it... at least, that's the theory I'm working off of.
As long as I can keep the system under 200F with high ambient temps, I'll be happy. I don't have anything fancy like a FLIR camera, but I am going to get one of those laser pointer temperature probes.
If the big slab of aluminum can't keep things cool, I'll ditch the plastic fixtures entirely and go with a recessed heat sink in the ceiling. There's a new piezo-electric LED cooler I've been wanting to try. :)
