led + cfl lights question

Ace Yonder

Ace Yonder

Well-Known Member
az2000 said:
In 2010 Cree anounced they broke the 200 l/w barrier. Last May they announced the commercial availability of that performance:

"XLamp® XP-L LED, the first commercially available single-die LED to achieve breakthrough efficacy of up to 200 lumens per watt (LPW) at 350 mA"
-- http://www.cree.com/News-and-Events/Cree-News/Press-Releases/2014/May/XPL-intro

XP-L is the diode the new Area-51 models will have. (<<link). Expected in April. (<<link)

I like the simplicity of the E27-base (screw-in) lightbulbs. No cooling fans, distributed lighting with more sources of light from different angles. They're ~100 LPW for the Cree A19 lightbulb (Home Depot) and ~110 for the SMD 5730 "corncob" bulbs sold on AliExpress (presuming they're not counterfeit).

You can get a fanless 140 LPW from COBs if run at lower current and on larger heatsinks. That requires a considerable investment in aluminum heatsinks and cobs (need more for total lumens when running them at lower current). I'm sure it pays for itself, but I think even at lower power they're still not the best choice for smaller grow spaces. Seems they still can't be placed right up against the plant for diffuse light like the Cree A19 (Home Depot) bulbs.

T5HO is about 92 LPW. The Cree (Home Depot) bulbs are ~92 LPW with their frosted diffusion globe (would be ~100 LPW with that broken off, which some people do -- but you need to put plug it into a GFI to make those exposed surfaces safe). The SMD 5730 is about ~105-110 LPW in its clear plastic globe (not as diffuse).

So, it's an interesting time right now as LED tech is turning a corner. Commercial brands have COB lights they'll release soon (140-160 LPW). A51's XP-L. Over time, as the manufacturing processes mature, these efficiencies will make it into the screw-in lightbulbs.

I don't see any reason to use CFL right now unless it's a cold climate and a person needs the heat from CFLs. T5HO is on the fence with me. It's fairly efficient but doesn't have great penetration. You can get these 90-100 LPW LEDs in a PAR38 spotlight (18w actual) for greater penetration.

I used to grow T5HO. I still have the fixtures and thought about using them this winter. But, the options for concentrating them or breaking them up into more discrete, aimable, positionable sources of light seems like a downside compared to the equally efficient "lightbulbs" that are now available. Maybe T5HO offers something I'm overlooking.

Either way: grow light technology is turning a corner right now. In a couple years I think T5HO will be comparatively the same as CFL is today. I don't think the high-powered COBs and XP-L chips are going to do it because T5HO is good for that up-close diffuse light. But, in a couple years those efficiencies will find their way into softer lightbulbs.
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The 21st century lamp competition isn't for a high efficiency diode tho, it's for a screw bulb that can replace incandescent lights with the same color temp. So to win the competition it's not enough to make a 200 l/w diode, they need to make it into a bulb (like the home depot ones) that has the 150+l/w and correct color temp. I'm not saying 200 l/w diodes aren't impressive, it's just not what the comp is looking for.
 
jb4TWENTY

jb4TWENTY

Well-Known Member
i guess post some pics of ur plants with white led lets make some believer's.. but ive seen minimum too none using white led only.
 
jb4TWENTY

jb4TWENTY

Well-Known Member
but whats different between your white LED and other LED panels? i see you're doing thee damn thing with your grow. but ive seen equal or better with other lights. correct me if im wrong
 
A

az2000

Well-Known Member
jb4TWENTY said:
i see you're doing thee damn thing with your grow. but ive seen equal or better with other lights.
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It depends on how you quantify what you see. Grams per watt? Watts per sq. ft? If you're just looking at photos it's hard to tell if it's 50w/sq ft of Mars (inefficient epi-whatever diodes). Or, if it's airy buds which will yield 0.8g/w.

I do have 3-4 traditional blue/red lights (inefficient epistar chips) and Cree whites beat them hands down. However, that's not a fair comparison of spectrum because the difference between Epi and Cree is substantial.

As mentioned in a previous post, I'm not completely on board with all white. I (and others) believe the RW (red white) performs the same as the XGS but with less watts. The difference (visually) is a warmer white than you can buy as a white LED. Not the unnatural blurple color of spectrum which seems to be a legacy of the days when white wasn't viable.
 
nomofatum

nomofatum

Well-Known Member
az2000 said:
It depends on how you quantify what you see. Grams per watt? Watts per sq. ft? If you're just looking at photos it's hard to tell if it's 50w/sq ft of Mars (inefficient epi-whatever diodes). Or, if it's airy buds which will yield 0.8g/w.

I do have 3-4 traditional blue/red lights (inefficient epistar chips) and Cree whites beat them hands down. However, that's not a fair comparison of spectrum because the difference between Epi and Cree is substantial.

As mentioned in a previous post, I'm not completely on board with all white. I (and others) believe the RW (red white) performs the same as the XGS but with less watts. The difference (visually) is a warmer white than you can buy as a white LED. Not the unnatural blurple color of spectrum which seems to be a legacy of the days when white wasn't viable.
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They aren't "inefficient" they just aren't the most efficient. If you drive a 3w at 2w you get north of 110lm/watt. That's plenty efficient for me.
 
A

az2000

Well-Known Member
nomofatum said:
If you drive a 3w at 2w you get north of 110lm/watt. That's plenty efficient for me.
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That may be true for real Taiwanese Epistars. The problem as I understand it is that you can't know what you're getting because Epi licenses its tech to mainland manufacturers. Or, a mainland factory may purchase dies from Epistar and perform the assembly and encapsulation. That's what plagues the typical fixtures originating from China. (Apollo, Mars, Baesheng.).

Not sure how that polluted supply chain could affect DIYers procuring chips through distributors. (DIYers seem to gravitate toward Cree, Osram, Luxeon, et al.).
 
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