alesh
Well-Known Member
Has anyone actually seen the 4T?
How efficient are blue used in COB ?
- Thread starter speedyganga
- Start date
i talked with sanlight @ cannafest in prague 2 weeks ago, they claim they get a special selected bin similar to 4t which they use in their new s4w panels (not yet on their website, 300ppf out of 140w according to the flyer)
https://www.greenlight-shop.de/media/pdf/datenblatt-sanlight-s4w.pdf
https://www.greenlight-shop.de/media/pdf/produktflyer-sanlight-s4w.pdf
https://www.greenlight-shop.de/media/pdf/datenblatt-sanlight-s4w.pdf
https://www.greenlight-shop.de/media/pdf/produktflyer-sanlight-s4w.pdf
speedyganga
Well-Known Member
300ppf is huge for a 140W commerical grow lamp... Passive design, and oslon, impressive lamp, how much is retail price ?
Positivity
Well-Known Member
What's been available are either 2t-3t or 3t-4t. I've never seen them separated. Maybe to more easily sell led bins evenly.
Makes me wonder if I tested my 3t-4t would I end up with two distinct performances. Hand selected 4t for the sanslight?
Somewhere supra had a chart comparing Cree photo red and I thought I remembered the Cree coming out ahead. So thermal performance characteristics would than be the next thing to look at
But really, what's available is the best to me. If it's a oddity I rather wait until it becomes reasonably available.
Positivity
Well-Known Member
@SupraSPL
Thanks. Looks like the philips got passed up a bit, all pretty close. I like using top bin cobs when possible but when adding colors I'm not really concerned about efficiency. At least not compared to cobs. More concerned about running with a broader spectrum. Keeps my small grow interesting...stuff like that..
Thanks. Looks like the philips got passed up a bit, all pretty close. I like using top bin cobs when possible but when adding colors I'm not really concerned about efficiency. At least not compared to cobs. More concerned about running with a broader spectrum. Keeps my small grow interesting...stuff like that..
they sell with shops, so it's quite steep, 530eur/each :/
fun fact: i asked what they think of cobs. according to them, they are not so usefull in a growing environment due to the phosphor degrading over time because the plants emit something that weakens them? anyone ever heard of that?
SupraSPL
Well-Known Member
Cannabis terpenes are volatile organic compounds (VOCs) so the LEDs will be exposed to some amount of VOCs. That said, I have several CREE XRE 6500K Q5 LEDs in my cloning box that have been in use almost non stop since ~2008. They are phosphor based and have been sharing the same air with flowering plants. It would be interesting to compare the output with a brand new one.
This report addresses the issue but they are talking about LEDs trapped inside hermetically sealed fixtures with VOCs. Apparently the damage to the LED is visible and it affects blues LEDs as well. Only certain VOCs are incompatible with LEDs, so Cannabis terps may or may not be a problem.
From time to time I have accidentally smeared trichomes onto the surface of a bare COB when moving plants around. It comes off with alcohol and no visible damage from VOCs.
CREE and OSRAM chemical compatibility notes
Page 5 of the CREE note shows how VOC affected LEDs will outgass the VOCs once exposed to a VOC free environment and the LED returns to full output. It would be interesting if we could find a picture of a VOC affected COB.
This report addresses the issue but they are talking about LEDs trapped inside hermetically sealed fixtures with VOCs. Apparently the damage to the LED is visible and it affects blues LEDs as well. Only certain VOCs are incompatible with LEDs, so Cannabis terps may or may not be a problem.
From time to time I have accidentally smeared trichomes onto the surface of a bare COB when moving plants around. It comes off with alcohol and no visible damage from VOCs.
CREE and OSRAM chemical compatibility notes
Page 5 of the CREE note shows how VOC affected LEDs will outgass the VOCs once exposed to a VOC free environment and the LED returns to full output. It would be interesting if we could find a picture of a VOC affected COB.
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ttystikk
Well-Known Member
Yes, I've heard of that. It's called BULLSHIT, LOL
if you want to compare efficiency numbers between cobs (phosphors) and monos then you at least need to compare one that's a little bit close in spectrum. say 2700k or lower to deep reds. A 6500K to royal blues.
Since I use monos to supplement cobs I actually only care about the efficiency to produce a narrow wavelength band, which means I would actually have to filter out most of the light from a cob. for example, to supplement the deep red zone I can use a deep red mono or a cob with light above 600nm filtered out (~20%).
heckler73
Well-Known Member
I would say it is not a problem. Consider also the test conditions; hermetically sealed, no intermediate materials.
I think general wear'n'tear is the biggest problem one has to be concerned with, unless you are sticking your LEDs in some beaker of alcohol.
SupraSPL
Well-Known Member
@PurpleBuz Including deep red may be an individual goal of your build, but it is not required. So if a DIYer allocates some of their watts/money on a 50% efficient deep red, they made the decision not to spend those watts on the cheaper 64% warm white. That difference is not small and spectral tweaking cannot make up for it, in my experience.
KNNA originally believed that tweaking the spectrum would give us an additional edge over HPS but he found himself using more and more white LEDs, and we have continued in that direction. So far it seems to be much easier to clobber HPS with raw efficiency/photons rather than spectrum. I am all for experimentation, but I have seen evidence that efficiency trumps spectrum, especially considering the 3500K 80 CRi DOES have a very effective flowering spectrum on its own. Most recent batch was over 1.45gpw in 56 days, ROLS, mid yielders, cool canopy temps 75-78F. Not sure I can repeat those results every time but I am going to give it my best.
KNNA originally believed that tweaking the spectrum would give us an additional edge over HPS but he found himself using more and more white LEDs, and we have continued in that direction. So far it seems to be much easier to clobber HPS with raw efficiency/photons rather than spectrum. I am all for experimentation, but I have seen evidence that efficiency trumps spectrum, especially considering the 3500K 80 CRi DOES have a very effective flowering spectrum on its own. Most recent batch was over 1.45gpw in 56 days, ROLS, mid yielders, cool canopy temps 75-78F. Not sure I can repeat those results every time but I am going to give it my best.
ttystikk
Well-Known Member
My recent experience with 860W CDM lamps would tend to confirm your point here; even 93 CRI isn't increasing yield, just better frost n flavor.
Personally, I think tweaking spectrum for desired effects is still in its infancy and I think there are plenty of opportunities to alter growth patterns using them.
Example; if you veg under high Kelvin lighting like 6500k T5, it seems that the switch to HPS in bloom exaggerates the stretch.
If you're vegging under HPS and bloom under a high Kelvin light like the 4200k 315W LEC, your stretch might all but disappear!
Then there's the well known benefit of UVB supplementation.
What I'm sure of is the way to beat HPS is by brute force; more PPfd on the canopy. Spectrum is no shortcut. If it was, we'd all be happily running blurple panels!
speedyganga
Well-Known Member
Well, for me if one could replicate the closest possible canna absorption spectrum with a high efficiency we would get the first real horticultural light cob for our purpose. We need phosphor !!!
ttystikk
Well-Known Member
@SupraSPL I was directed to a craigslist ad about a large LED light for vertical grows, link;
http://denver.craigslist.org/grd/5291622932.html
420 x 3 W diodes = 1260W from the wall.
He wants $1500. What do you think? I'm thinking I could bloom with it until my COBs get here and then it could go into veg...
http://denver.craigslist.org/grd/5291622932.html
420 x 3 W diodes = 1260W from the wall.
He wants $1500. What do you think? I'm thinking I could bloom with it until my COBs get here and then it could go into veg...
SupraSPL
Well-Known Member
http://plantozoid.com/extreme-420x-pro-vertical-led-grow-light-review/
615W draw, maybe 510 dissipation W. As far as I can tell they are generic epileds. So if we cal it 20% efficient, that is 102 PAR W or $14.70/PAR W. About the triple the price of a good commercial COB unit
Interesting design though, if you replaced the epileds with COBs it might be interesting to experiment. I would offer him $200 and that is probably generous.
615W draw, maybe 510 dissipation W. As far as I can tell they are generic epileds. So if we cal it 20% efficient, that is 102 PAR W or $14.70/PAR W. About the triple the price of a good commercial COB unit
Interesting design though, if you replaced the epileds with COBs it might be interesting to experiment. I would offer him $200 and that is probably generous.
ttystikk
Well-Known Member
That's THEIR opinion. I was asking for one I trust; yours.
ttystikk
Well-Known Member
Me? Jump the gun? Never! LOL
The stated draw is 5.3A@240V, that sounds like a lot more watts than you're calculating for. I have a Kill-A-Watt and it apparently runs on 120V as well, so I could take my meter with me and get an actual reading.