My LED plant grow light

[Stromberg]

Hello!
I got tired of killing plants, especially those that were given to me as a gift. So I built this grow light and it really seems to make a difference:

I've used the light few hours/day and not only have the plants survived, but actually they seem to flourish.

The fixture is some old E27 ceiling light that I gutted for this project and leds are 3watt "Prolight" -brand from www.Led1.de. Led driver is normal 230V -> 700mA also from Led1.de. It has 3 reds and one blue led glued(Arctic Silver thermal adhesive) on aluminium heatsink. I added small 12V fan and I'm driving it by 6V so the noise isn't so bad. The fan isn't probably necessary but I wanted to maximize the lifetime of the leds.

 

[kethd]

Thanks for the pix! How long have you been using/growing with this? Your fixture looks quite attractive from the outside, in the pic...

It would be interesting if you had a way to measure the heat sink temp, with and without the fan running.

It would be interesting to know if adding vent holes in the top of the shell to let the hot air out would make much difference.

The shell is sheet steel? Your heat sink is not much connected to it thermally? Wonder if that would make much difference -- might be hard to do, since it is curved...

Might have been better to try to spread out the stars on the heat sink a little more? As long as the fan is running, might not make much difference...

 

[Stromberg]

How long have you been using/growing with this?

Maybe two months now. Too bad I didn't take any pictures at that time because it would have been nice to make some "before / after" comparison.

It would be interesting if you had a way to measure the heat sink temp, with and without the fan running.

It would be interesting to know if adding vent holes in the top of the shell to let the hot air out would make much difference.

In fact there are several vents on the top but I think they make very little difference of cooling the heatsink. Sadly I didn't measure temp with/without the fan(laziness..), but I did some basic testing: without the fan heatsink got relatively warm (I'd estimate about 45°C) in few minutes whereas with the fan it gets only mildly warm(about 33-34°C) no matter the runtime. Anyways the fan isn't really a problem, its very small(power consumption is negligible) and quite silent.

The shell is sheet steel? Your heat sink is not much connected to it thermally? Wonder if that would make much difference -- might be hard to do, since it is curved...

Might have been better to try to spread out the stars on the heat sink a little more?

Yes it's steel so it would make poor standalone heatsink. I considered using bigger heatsink without additional fan but I think that spreading 3 red and one blue in larger area would have been bad for the color distribution.

 

[Marcturus]

I strongly advise anyone intent on doing business with Led1.de to be aware of the specifics in their Legalese section. While others may come to a different conclusion, it was the reason for me not to do any business with them. That's all - period.