Temperature..
While some effort is required in this direction almost all the builds we're seeing, with the exception of Stu's:lmao:, are massive overkill. Note my recent build. That's just 0.063" Al with some simple fins. Even that is more than necessary! We should step back and recognize that trying to get 10 years out of these fixtures is folly.
Look how far the state-of-the-art HBLEDs have gone in the last 3 years. We are at 100 lumens per watt now. It is expected that we will be at 150 lumens a watt in something like 2 years. Are you really going to want your same old fixture running over your same old tank in 10 years, when your fixture is costing you perhaps three times more to run than a newer fixture? That's way after the time you should've recycled your present one just to save energy costs.
Spending a fortune on aluminum and running 6 fans for a wind tunnel sound effect is not the way to go.
I recently researched this for my build.
How hot?
This is how hot:
One hundred fifty eight degrees F directly behind the center of the star on your heatsink's base metal - not fins - is where we should be aiming.
That puts the LED's operating temperature on the far far left of the recommended operating curve for lifetime. The curve goes far to the right from there. How far? The curve goes to 302F!!!
So, even though in the past I've suggested if you can touch it you're certainly cool enough I've changed my opinion. With my new understanding I'm upping that recommendation to a value that actually makes more sense. 158F
158F is instantly painful to the touch. That's a reasonable temperature - as far as the HBLEDs are concerned. At that temperature the L70 is still seventy thousand hours that's 19 years!!! LEDs will probably be 1000 lum/W by then and our fixtures will be long dead, economically and aesthetically.
Save some money and start aiming for too hot to touch directly behind the LEDs and really, really warm heatsinks.
