LED / COB cool down period

jjng5 said:

I did post the link to ebay... it's listed above? Can you help me understand why it's "garbage"?

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as he said up above it produces 60 lumens per watt of electricity consumed, thats atrocious for white, full spectrum LED. modern diodes including cobs can get over 200 lumens/watt. so its a very inefficient light.
as the other guy said, notice how they don't tell you who manufactured the COBs themselves. Thats a red flag.
Another red flag is the marketing saying its an 1800w lamp when its actually 300w.

some good COB manufacturers are Bridgelux, CREE, Citizen, or Luminus. If you don't see them advertised as part of a lamp, I wouldn't get it.

where to get real COBs:

www.rapidled.com
www.timbergrowlights.com

I am looking for some supplemental LED lighting for 2 x 600W HPS lights. Are there some DIY kits you'd recommend that are reason in price?

what size is your grow space

jjng5 said:

I am looking for some supplemental LED lighting for 2 x 600W HPS lights. Are there some DIY kits you'd recommend that are reason in price?

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I posted the kits on the first page from hlg

There are two HPS air-cooled lamps; one in a 4.54' x 4.54' tent and two 600W air-cooled lamps in 5' x 5'. In using a lux light meter, the corner and sides of the tent were very low in light. SWIM wanted to supplement with two LED sources.

I'm looking at the 260W QB V2 LED kit that Jtrizzy recommended. I see that these are two QB's put on one pannel -- I wonder if there is a way to separate the panel into two smaller panels somehow. Hmm...

Yes
You can buy the panels separately and get a driver that will drive both boards.

jtrizzy said:

Yes
You can buy the panels separately and get a driver that will drive both boards.

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SWIM just cancelled the cheap COB light and is receiving refund.

So you're telling me that I can buy two separate panels and use one meanwell driver to drive both boards? Is that right? I see that they also sell 135W single square panel. I'm trying to figure out what is best. Do you own one of these? Are they pretty powerful for flower? How is their penetration?

SWIM is at 40W / Sq ft in HPS in one tent and 48W / Sq Ft in the other tent. These HLG lights seem to be very energy efficient (esp. their new V2's)... hmm..

jtrizzy -- have you seen the items on cobkits.com? Maybe more affordable?

I like what I'm seeing on these QB's from HLG... they're just pricey and I'm not entirely sure how much light is needed because as mentioned above, there's currently 40-48 watts per sq foot from two HPS lights per tent (4 HPS total -- all air cooled). The goal is to have an optimum foot print equal to quantity of light to match the need -- there's no sense in having air-cooled tubes if you cannot lower the lights closer to the plants, am I right?

Could one get away with a 3 foot "XL" panel / heat sink board with either 2 or 3 QB boards and run it down the center of the tent with the HPS positioned laterally. In other words, the QB running down the center in-between the HPS lamps? I feel like it might almost be best thought to get 4 solo QB panels and position them in each of the four corners of each tent (or get the 3 foot XL panel with two QB's spaced out -- basically the same thing)... but then this starts to get even pricier.

@jtrizzy can you help guide me on the light needed first, before SWIM figures out foot print... Do you have experience with these?

I would say that the typical efficacy bump using the LM301b diodes compared to a HPS would allow you to use 1/3 less wattage to get the same photon output. Most folks are able to get 500-800 umoles at the canopy with 30w/sq ft with those fixtures.

GBAUTO said:

I would say that the typical efficacy bump using the LM301b diodes compared to a HPS would allow you to use 1/3 less wattage to get the same photon output. Most folks are able to get 500-800 umoles at the canopy with 30w/sq ft with those fixtures.

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Okay that is helpful. It sounds like SWIM is going to have too much light (more than usable by the plant) in this case. In addition to having adequate lighting, there's equal priority on light footprint. I've heard that while LED's are super efficient, they don't have much penetration and quickly lose power the further from the light source. SWIM wants good light distribution over a 5x5 space -- remember that two HPS with cool-tubes will be used.



What do you think based upon your experiences with LED's? SWIM has only used HID so this is a new challenge.

Thanks for your help!

jjng5 said:

Okay that is helpful. It sounds like SWIM is going to have too much light (more than usable by the plant) in this case. In addition to having adequate lighting, there's equal priority on light footprint. I've heard that while LED's are super efficient, they don't have much penetration and quickly lose power the further from the light source. SWIM wants good light distribution over a 5x5 space -- remember that two HPS with cool-tubes will be used.

View attachment 4282616

What do you think based upon your experiences with LED's? SWIM has only used HID so this is a new challenge.

Thanks for your help!

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Not to throw a wrench in the mix but why not just use 1x 1000w xl hood per room? It’s only a 5 x 5. I think your over doing it with all these lights in my opinion but it’s your money brother.

jjng5 said:

Okay that is helpful. It sounds like SWIM is going to have too much light (more than usable by the plant) in this case. In addition to having adequate lighting, there's equal priority on light footprint. I've heard that while LED's are super efficient, they don't have much penetration and quickly lose power the further from the light source. SWIM wants good light distribution over a 5x5 space -- remember that two HPS with cool-tubes will be used.

View attachment 4282616

What do you think based upon your experiences with LED's? SWIM has only used HID so this is a new challenge.

Thanks for your help!

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The whole penetration argument is generally bunk. Having a single source of light does not magically make photons go through leaves... it’s the quantity and spread that makes the most difference. One reason a lot of people are using HLG or Atreum boards is because they are more spread out. It allows for more angles of light to hit the plant.

Think of it like shining a single bright flashlight from behind a watermelon... there will be a large unlit area where the other side is eclipsed by the watermelon. If you instead use 20 smaller flashlights spread out, the light will reach areas that would have been eclipsed using a single light.

jtrizzy said:

Not to throw a wrench in the mix but why not just use 1x 1000w xl hood per room? It’s only a 5 x 5. I think your over doing it with all these lights in my opinion but it’s your money brother.

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SWIM wants to be able to have better light distribution than 1 point of light. For many of the same reasons that DesertPlants describe. I have found that with a single light source you end up with great results in the center of the space with average results elsewhere and below average results in the corners. Just IMO...

SWIM even purchased a LUX meter to measure the lamps before deciding about additional or supplemental light. Also SWIM wants to be able to move the lamp closer to the plants for better efficiency. You cannot move one HID close to the plants without also narrowing its foot print of course. Hence; the desire for added light sources.

HID is not the issue -- 2 x 600W HPS along with the cool tubes are already here and ready to install into the two flower tents (4 lamps total).

DesertPlants said:

The whole penetration argument is generally bunk. Having a single source of light does not magically make photons go through leaves... it’s the quantity and spread that makes the most difference. One reason a lot of people are using HLG or Atreum boards is because they are more spread out. It allows for more angles of light to hit the plant.

Think of it like shining a single bright flashlight from behind a watermelon... there will be a large unlit area where the other side is eclipsed by the watermelon. If you instead use 20 smaller flashlights spread out, the light will reach areas that would have been eclipsed using a single light.

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I understand. Based upon the HID light already in place, do you believe that two QB's boards (~130W each) would be sufficient or would you put one QB in each corner of the space (four total)?