Chinese -Leds

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LurchLurkin

Active Member
Ace, as I said, light takes time to dissipate as heat and also microwaves heat from the inside out which makes them more efficient at heating things quickly. A microwave with the same energy as a stove will heat food faster
 
nomofatum

nomofatum

Well-Known Member
Ace Yonder said:
If this were true, a 1000w microwave oven and a 1000w light in a sealed reflective box would boil a cup of water at the same speed.
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Water doesn't absorb visible light well, it does absorb microwave light however. To heat the water with visible light you would have to try to heat the bowl it's in and let the heat tranfer by conduction. The amount of heat energy is the same one is just better targeted to your medium. Now try to heat up a black piece of paper in the microwave vs under a 1000w light. But in a sealed system, you are releasing the same amount of heat energy regardless of the device (with the exception of the very tiny percent actually absorbed by the plant, and any light/sound that escapes.)

Most of the light the plant absorbs is still put out as heat FYI.
 
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LurchLurkin

Active Member
Positivity, because you need to be measuring PAR, not lumens, and you need to compare the spread of light from one expensive one vs many cheaper ones. Also ensure that the expensive one doesn't provide wasted light to the center by exceeding the plants capacity.. Can be as efficient as you want with the diodes but if the plant can't use it then oh well might as well be cooking the diodes.. But if you back away LEDs lose power faster than HID and don't have the spread.

I'm saying for financial and practicality reasons it's probably better to put 5 of the $100 lights in your little tent instead of one big expensive light with better diodes, equal wattage or not.
 
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LurchLurkin

Active Member
Also, I'm guessing that if you want to compare results with HID you probably need somewhere between 50-60 watts per square foot.. Do it with a bunch of small panels and you're utilizing the electricity much better than HID and will Watt for Watt get better results provided the lights are half as decent. I've spoken with the factory owner of LG led and the Chinese engineers aren't stupid, but like nute companies they will sell what you will buy. If you want to order 200 lights they'll put Cree LEDs in them for you and use whatever drivers etc.
 
Positivity

Positivity

Well-Known Member
But if you build one good light it'll run forever..and spare me 20 light hangers.

few runs in and i think i'm still seeing light lumen appreciation...just broken in...instead of broken..:razz:

All comes to personal preference ...i feel 400w is just about right for one fixture..maybe more...:peace:.
 
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LurchLurkin

Active Member
More lights allow more even spread which are more efficient than one light, preferably they would daisy chain themselves together
 
captainmorgan

captainmorgan

Well-Known Member
I like more lights for a even spread,no plant rotation needed either. Looking forward to testing out the new Area 51 light,suppose to be a smaller panel closer to around 100 watts,maybe like the XGS split length wise.
 
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Ace Yonder

Ace Yonder

Well-Known Member
nomofatum said:
Water doesn't absorb visible light well, it does absorb microwave light however. To heat the water with visible light you would have to try to heat the bowl it's in and let the heat tranfer by conduction. The amount of heat energy is the same one is just better targeted to your medium. Now try to heat up a black piece of paper in the microwave vs under a 1000w light. But in a sealed system, you are releasing the same amount of heat energy regardless of the device (with the exception of the very tiny percent actually absorbed by the plant, and any light/sound that escapes.)

Most of the light the plant absorbs is still put out as heat FYI.
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Here, this is a practical application of the concepts. If you were correct than these tests would have DRASTICALLY different results than the actual tests show, namely the heat output would remain constant based on wattage and not fluctuate as efficiency changes. But in the real world, 60w produces much different levels of heat depending on the efficiency of the bulb, it just does, no way around it.
http://www.reptileuvinfo.com/html/watts-heat-lights-lamp-heat-output.html
"We placed a 60 watt external ballasted mercury vapor lamp and a 60 watt halogen lamp in two separate insulated boxes with a thermometer inside. If both lamps put out roughly the same amount of heat, these two lamps should have effectively raised the temperature in both boxes to the same degree. After 30 minutes, the thermometer in the container with the halogen lamp gave a reading 20°F higher than the other box, (135°F vs 115 °F) and the heat from the halogen lamp had actually warped the plastic!" (And for reference, the ballast is in the box as well, so no heat is being generated outside the box to justify the lower heat, only efficiency)
 
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SupraSPL

SupraSPL

Well-Known Member
nomofatum said:
Nothing. I haven't seen anything showing Cree are better from anyone either though. We need a side by side. So either a Cree user has to bite the bullet to backup their claims or I have to buy a cree system to backup mine by your logic. Well it's a cheaper investment for you to buy an epistar system, so get to it if you want to talk shit like you are.
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I am willing to buy a few and run some caloric tests. Do you have a link to the ones you would like me to check out?
 
SupraSPL

SupraSPL

Well-Known Member
LurchLurkin said:
If you want to order 200 lights they'll put Cree LEDs in them for you and use whatever drivers etc.
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Organic soil makes for much better tasting buds. My patients can even pick out chem soil versus organic soil and will pay more for organically grown. Imagine if you were being fed intravenously. There is no way the mixture be just right for what you need, every time. Your gut lining and microbes would do a much better job and a lot more efficiently overall. Same goes for the plant, by feeding the soil and letting the plant take up what it needs, you get a much better quality than force feeding. Even beginners look like masters when given a good cutting and good organic soil to grow in.

You are correct, most of the photons convert into heat anyway BUT you get the job done (photosynthesis) with much less dissipation by running them at high efficiency, so there will be a lot less heat in the system.

No generic LED company has built with CXA3070 3000K ABs and if they ever do, we will be on to something much much better by then. Even if they did use quality chips, they would probably be running hard and poorly cooled. When they mention Cree, they are talking about low-mid bin XPE and XTE reels. Low-mid bin Crees would be a huge improvement over the generic chips though.
 
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LurchLurkin

Active Member
"BUT you get the job done (photosynthesis) with much less dissipation by running them at high efficiency, so there will be a lot less heat in the system."

Only if the plant can use the light before it dissipates to heat. I've not done tests and I don't grow or smoke pot but I enjoy scientific discussion, and the cheap lights at lower watts spread over the canopy is more efficient than one expensive light in the center pulling the same watts. Is the expensive light so much more efficient that it compensates for this? I doubt it, but only rests on a 4x8 table would show... And I think the cheap lights will have a bigger chance of winning as the watts per sq ft goes up.

Even if they are cooking the diodes and being less electrically efficient they may be more photosynthetically efficient when you factor in the distribution, actual PAR, and the plants efficacy in using that PAR. You really have to look at initial investment costs too since as you said, technology advances rapidly and they need to produce more profit before they ultimately become obsolete.

I'm not saying that the cheap lights truly are better, I'm just saying there are better ways to evaluate.

I still don't believe in the soil/organics either. I don't believe in flushing and I don't believe in lollipoping, I only believe in scientific research done impartially and I'd like to see a double blind study on the taste.
 
alesh

alesh

Well-Known Member
LurchLurkin said:
"BUT you get the job done (photosynthesis) with much less dissipation by running them at high efficiency, so there will be a lot less heat in the system."

Only if the plant can use the light before it dissipates to heat. I've not done tests and I don't grow or smoke pot but I enjoy scientific discussion, and the cheap lights at lower watts spread over the canopy is more efficient than one expensive light in the center pulling the same watts. Is the expensive light so much more efficient that it compensates for this? I doubt it, but only rests on a 4x8 table would show... And I think the cheap lights will have a bigger chance of winning as the watts per sq ft goes up.

Even if they are cooking the diodes and being less electrically efficient they may be more photosynthetically efficient when you factor in the distribution, actual PAR, and the plants efficacy in using that PAR. You really have to look at initial investment costs too since as you said, technology advances rapidly and they need to produce more profit before they ultimately become obsolete.

I'm not saying that the cheap lights truly are better, I'm just saying there are better ways to evaluate.

I still don't believe in the soil/organics either. I don't believe in flushing and I don't believe in lollipoping, I only believe in scientific research done impartially and I'd like to see a double blind study on the taste.
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I agree that vast majority of light, ultimately, gets dissipated into heat.

I, however, disagree on all other points.

I see no difference in distribution of light. Yes, even highly efficient lights can be spread well. I highly doubt that cheap lights would produce PAR that plants use more efficiently. Actually I think the opposite might be true.

And yes, expensive lights (especially if we're talking DIY) can be that much more efficient than some generic LEDs. Depends on what you get, but I'm talking efficiency anywhere between 5-20%. 25% for royal blues and some cool whites. With high end LEDs you can reach almost 60% (extremely expensive) but 45% can be achieved for a reasonable price. That is one thing. The other is that cheaper LEDs are worse packed (resulting in higher temps). Especially in case of multichips, they are very are unreliable (due to poor die selection and bad thermal balancing). They drop output extremely fast. And also, be aware that a lot of Chinese sellers lie right into your face (my personal experience about LEDs).

In the end I am not gonna go with cheapo LED lights.
 
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LurchLurkin

Active Member
"I see no difference in distribution of light. Yes, even highly efficient lights can be spread well."

LEDs tend to have a maximum beam angle of 120 degrees. This means that the light extends 60 degrees to either side at which point half of its PAR is already lost as heat. Now think about it as a triangle, half of 120 is 60, and 60-60-60 is an equilateral triangle (this is for 120 only, lower angled lights will require you to use trigonometry)

So now if you have 2000 Einstein 18" below then 18" off to the side you will have half of that. You must have another light 18" away to overlap in order to maximize efficiency at 80 degrees and 1200ppm co2, beyond this there are no studies I'm aware of.

You might be able to do this fine with one plant but you won't be able to do this over a larger area.

In practice I've not read any of your grow journals that show your diy lights or expensive lights that show much better results than I've seen others do with the cheap lights to justify the cost.
 
alesh

alesh

Well-Known Member
LurchLurkin said:
"I see no difference in distribution of light. Yes, even highly efficient lights can be spread well."

LEDs tend to have a maximum beam angle of 120 degrees. This means that the light extends 60 degrees to either side at which point half of its PAR is already lost as heat. Now think about it as a triangle, half of 120 is 60, and 60-60-60 is an equilateral triangle (this is for 120 only, lower angled lights will require you to use trigonometry)

So now if you have 2000 Einstein 18" below then 18" off to the side you will have half of that. You must have another light 18" away to overlap in order to maximize efficiency at 80 degrees and 1200ppm co2, beyond this there are no studies I'm aware of.

You might be able to do this fine with one plant but you won't be able to do this over a larger area.

In practice I've not read any of your grow journals that show your diy lights or expensive lights that show much better results than I've seen others do with the cheap lights to justify the cost.
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While I can't say that I agree with your view on optimizing light distribution, that is not the point. What I meant was that same rules about beam angle and shape apply to both cheap and expensive LED lights. So you can't say that cheap lights have an advantage here.

I think that higher efficiency and reliability do justify the cost. I've written what I felt was needed to be written and we can perhaps agree that we don't agree with each other?
 
A

az2000

Well-Known Member
alesh said:
What I meant was that same rules about beam angle and shape apply to both cheap and expensive LED lights. So you can't say that cheap lights have an advantage here.
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I think what he's saying is that inefficient lights are more cost-efficient to apply in smaller doses all around the plant (for uniform coverage), and that the improved efficiency of this light delivery would compensate for the initial inefficiency of those epi-whatever fixtures.

I don't know if that's true or not, but I think that's what he's saying. It sounds like a reasonable assumption worth proving or disproving.

Regarding distribution of light sources around a plant versus a single strong point, there are knowledgeable growers who say the former is better. Stardustsailor designed his Astir lights with this view. Captainmorgan said he prefers it. I'm not anywhere near their league, but I subscribe to the same thought.
 
alesh

alesh

Well-Known Member
Maybe I'm dumb, but I don't get it.

You can have cheap lights as a single source. You can have cheap lights evenly spread.
On the other hand...
You can have expensive lights as a single source. You can have expensive lights evenly spread.

How is that an advantage for cheap light, that I cannot see.
 
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LurchLurkin

Active Member
I know what you're saying..

If the lights produce light more efficiently, the plants used it just as effectively, and distribution was just as good then the better diodes would be a win.

But when you are looking at costs of the unit compared to the actual performance you're all getting, they don't look more appealing. Especially with the cost difference they'd have to be wayyyy better.
 
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