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Originally Posted by sphelps
Ok well these ones you sell come to mind
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Like Ron has already pointed out, these lights alone, weight about 1- 1.5bs Also these lights run at a temperature of roughly 50C, the whole debate about whether or not we need fans for the fixtures was the debate on how efficiently the heatsinks alone can dissipate the heat to keep the temperature as low as possible. At 50C the LEDs will surely work close to there rated 50,000hrs life time. But the decrease in intensity will be larger over the course of the bulbs overall life.
Quote:
Originally Posted by sphelps
Also you could use a peltier system and regulate the current with a simple thermo switch so the surface stays at a consistent temperature just like fans so condensation would be no different. As long as the surface temperature stays at or above ambient you won't get condensation.
The bottom line is many high powered systems already exist which don't use fans so it can be done and it can still be done better. I'm not sure why you all feel the need to debate that, if you like fans go nuts but I'd prefer a system without fans. It's a simple personal preference I guess, and I'm entitled to it.
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A peltier system wont work without a fan im afraid, you need something to cool the hot side of the peltier or it ends up heating up both sides, so either way there needs to be active cooling in the use of peltiers.
again the debate on whether or not fans were needed started based on the idea of keeping the heatsinks as cool as possible. But a system without fans will work, just not as efficient as those that has active cooling, as you'll most likely see an increase in intensity drop through the life of the emitters.
Quote:
Originally Posted by sphelps
I have some of the LED spotlights in use in my house, they are actually about the same weight as the halogens, much lighter than they look. A little bigger but certainly not heavier. The larger size is also due to need to include a driver not so much a result of the heat sink. The size difference is also only noticeable on the very small spotlights, pretty much every other type of house hold bulbs are of each size.
Keep thinking that if you want but you don't have to add more weight to increase heat sink efficiency. Applying individual finned heat sinks to each LED will not add significant weight and reduce the the need for an additional large heat sink. You could very easily decrease the weight of the fixture with proper design. LEDs don't generate a lot of heat, they are at least 90% efficient meaning a 3W bulb can't produce more than 0.3W of heat which is very little. The reason you need fans is because you're simply bolting one side of the of it to a large aluminum plate which isn't a very efficient way to remove the heat.
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Applying individual finned heatsinks to each LED would create uneven cooling to each of the heatsinks. unless your talking about a fanless system, if thats the case then you'll need some fairly well designed light weight heatsinks. If we were to mill the front face of the aluminum heatsink with fins down to about 1cm would it increase the efficiency? It'll move the heat towards the fins faster, but without active cooling/air movement your not doing much with the extra speed in heat transfer from the LED to the heatsink.
Maybe we'll see a fixture out there in the future that will be fanless and be able to keep the temperature at 30-40C, when that day comes i'll purchase one to test and throw a fan on top to increase the lifespan of my LEDs
(highly doubt it but i want to be optimistic)