4 Luminous COB´s LED in 600W tent

looc · February 12, 2020, 3:42pm

Hey and cheers.

I want to discuss a custom LED light with COB´s (chip on board) leds. It should be Luminous chips witch draw 140W from a wall and I will use 4. With Mean Well HLG 54V, 480W power supply i can run the chips with some (10 %) reserve on 2,03 Amps (108W) each. With optics with 93 % efficiency i can get 12 071 lumens from each chip and 48 284 lumens total. That´s 100,5 lm/W. In comparison with 630W cmh Lumatec witch efficiency is 111 lm/W that´s not bad-digital power supply is not so efficient instead i think. It is also pretty cheap light setup. Hardware (LED chips, DC power supply, optics) cost around 370 €-Luminous chips aren´t so expensive as Crees.

So it´s nothing new. And what do you think, are these chips good enough for 120x120 box?

I think this video is informative and i used it in my project.

ReikoX · February 12, 2020, 4:04pm

In my experience, the LED strips out perform COBs and are a lot cheaper to DIY. Check out what is being done with these strips.

looc · February 12, 2020, 9:27pm

I already bought the aluminium heatsink, 55 cm long, 3 pcs. First i thought i will grow in IKEA micro cabinet but it was too nice and the heatsink also. I will try maybe only 280 watts first but it’s not efficient setup then.

ReikoX · February 12, 2020, 10:20pm

COBs it is then! They work, better penetration, worse spread IME. I was still using my Cree cobs until a few weeks ago.

looc · February 13, 2020, 6:23pm

Exactly man, i researched more and i think best solution is now try 2 140W LEDs as i mentioned in last post with 320W driver. This is reasonable choice (HLG-320H-C2800A) and far more effective, it can pull 32 000 lumens. With some additional lighting it is enough for 1 sq. metre /400W tent. For 600W tent i will try Luminous horticulture LED in this setup.

For now i don´t know witch color temperature choose, 3000K or 3500K or mix (3000K and 4000K/5000K). This confuses me because i can´t find spectral diagrams.

ReikoX · February 13, 2020, 6:46pm

If you are going to use it solely for flower, I would stick with the 3000K, otherwise I would go 3500K for bot veg and flower.

looc · February 14, 2020, 9:38am

I ordered 2 3500K 140W chips, 3000K was not available at the monent :/.

ReikoX · February 14, 2020, 3:07pm

3500K is still a good spectrum for flower.

looc · February 19, 2020, 8:01pm

COB’s arrived. Driver on the way. It is HLG 150W. I will grow in small cab first and can use it to run only 1 chip on full load later. Square optics i think should work well with these:

looc · March 1, 2020, 8:22pm

COB´s are very hot (actually the heatsink), should I use the fan?

I´am running them on 700 mA probably.

looc · March 2, 2020, 10:12pm

I think the only right way is to get some scientific instrument like PAR meter. But plants do always tell too.

looc · March 9, 2020, 8:05am

I do a small improvement with the pair of 12V fans on a single power source. Chillish temperatures of 36 d. celsius is better than 48 d. c. before.

I grow some pepper plants along with weed.

looc · March 11, 2020, 3:57pm

So far good. This light cost me 180 euro, but i have 2 aluminium heatsink more so i can upgrade to 6 chips (450W) in larger tent and it will cost not even 3 times more (1 euro/watt is possible). Do you have something to comparison, please?

looc · March 11, 2020, 3:57pm

looc · March 15, 2020, 6:16pm

I am updating on the Sundays. Added two more fans on the same power source. It runs on 3V.

looc · March 22, 2020, 6:08am

Bump, update.

150W of LEDs light doing its job. Pics tell for itself. Tent is 1sq meter. I can say 3500K has much blue in it, plants are bushy and compact. 3000K would be better for flower but it is not available at the mouser.com, I need to add some red/orange in the spectrum. BIN of COBs is 80 CRI.

Next job is to light up the corners with 3W LEDs

looc · March 24, 2020, 7:16am

Love these SJ. I’ll do a thread soon too. This photo need some color balance, bwe.

looc · March 29, 2020, 4:41pm

Have some pH issues. I need to buy pH 4.0 and 7.00 to calibrate new pH meter. PH is most definetally too high.

SJ - Sannies jack, F7 or so.
20 days veg.

I hope they won’t need repot next 14 days. Got feed with 8-8-8 universal fertilizer. Epsom salt should be also good.

Aerial view

Zoom in

looc · April 1, 2020, 6:15am

I learned a ton from testing of these COBs.

provide optics for COBs - to come
provide enough space for each plant
provide air flow for both COBs and plants
provide oxygen (CO2 actually) with vent
feed less, water more (less but more often)

These 5 steps were necessary with strong COB light for good results with vegetables.

The results from vegetable garden

Pumpkins

Sweet peppers

Gpaw · April 1, 2020, 1:41pm

Nice setup you have there! The plants obviously love it!
Those heat-sinks are massive & they really go with the hangers, very functional with a steampunk like vibe.
If you have access to a IR thermometer it would be interesting to see the temperature gradient on the heat-sink but you would probably have to measure on the fin side.

If you ever need to lower your tent ambient temperature a simple fix would be relocate the driver to the exterior of the tent. That will reduce about 20~25 Watts of heat.

My only suggestion (a minor one) is to tidy up the wiring a little. It might avoid a potential accident down-the-road.

Cheers
G