#### Hoop

##### Enlightened

By the way, I want to say

Let me know if these numbers check out fellas!

**Big thanks to Illumination Supply**for coming through for me with this bulk order of Nichia 219A's!Thermal analysis... I new I forgot something! I only calculated the total surface area of the heatsink and made an assumption of whether it would be sufficient, and at first I was grossly underestimating the required surface area but SemiMan set me straight. Your post inspired me to run some numbers but I do not know if my values are correct. From what I have read these MCPCB stars add 3-5 °C/W (seems low) and the 219A sports a pretty poor TR value of 7 °C/W typical, so the total TR of the combo would be 12 °C/W worst case. The heatsink provides 19 in² of vertical surface per led plus some horizontal surface and also I will leave the ends open, but at 19 in² the heatsink will have a TR of 5°C/W. I am not sure if this figure is correct but I will roll with it.... So the total TR is 17 °C/W, and if the led consumes 5 watts, 4 of which are heat, the total temperature rise over ambient will be 68°C. The hottest it's going to get in my garage is 30°C, so the maximum Tj temp will be 98°C. I doubt I will actually be driving these suckers at full power very often, so they would typically be much cooler. At 600mA per led (1.6W of heat) there will be 360 lux in the shop space and the led junction temperature in 30°C ambient would be 57.2°C.Have you done any thermal analysis or measured a mock-up yet? Just curious how hot your tubing will get with whatever thermal load you're planning...

Let me know if these numbers check out fellas!

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