jarvild
Well-Known Member
Why else would you need a fan to cool a 35 watts module when you can cool a cob passively up to 100 watts.
⇧Brother OneHitDone's HydroGrowLed MEEt's LETTUCE Grow Test⇧
- Thread starter OneHitDone
- Start date
HydroGrowLED
Well-Known Member
Sweet deal! Nice little addition for the time being considering there is so much lit area that isn't growing anythingDecided to throw in a cannabis clone just to get a feel for how they grow under these lights until the lettuce is ready to be spread out
Our LEDs are run at 600mA last I checked. We ran them at 550mA for years and did bump the amperage to 600mA, but this had nothing to do with lens loss (as we've been running the Xlens since 2011). It had to do with the LED chips becoming more stable over time at higher drive currents resulting in less loss of output. For what it's worth, PMMA has a loss of about 7%, which is made up for by the fact that we are delivering nearly 100% of our light within our desired coverage area (whereas competitors often waste about 20% of their light on walls without using lenses). I'd call it a pretty smart trade-off, but you might disagree.
Despite our drive current, the heat sink is reading at 5 degrees above ambient level, and the lens is reading at 10 degrees above ambient.
You'll see in the graph above the light decay of red, blue and white LEDs based on temperature. 25C (77F) is the point at which we classify the LEDs at 100% output and is considered the optimal operating temp. Our LEDs are operating somewhere between 80-85F, which would result in about a 3-5% loss of initial output (for red) according to the graph (which isn't specific to any one manufacturer and is at least 5 years old). The blue and green LEDs on the other hand would be operating at 98-100%.
I'm not sure where you are drawing the conclusion that we are creating more heat which is shortening the life and reducing efficiency, considering we have one of the lowest operating temps in the industry (by design). With that said you are still welcome to disagree with me and maintain your own opinions.
HydroGrowLED
Well-Known Member
Cooling passively and cooling efficiently are two completely different things. I can also make our LED lights passive cooled (in fact with X-PRO this is an option we offer); however the heat sink temp rises to 135F (57C) on X3 which causes a spectrum shift and output loss from all LEDs. The same is true with a COB.
Most passively cooled COBs are running well above 135F. While white LEDs decay much less rapidly with temperature compared to red, their output is still diminished because of the operating temp.
We use fans to keep out operating temps stable as close to the optimal temperature as possible, not because we can't run the lights passively. We want to squeeze every last photon we can out of our LEDs so we aren't wasting energy.
@OneHitDone - if you want to open the light and disconnect the fan to re-do your temps you're welcome to. I would simply ask that you plug it back in afterwards to keep temps as optimal as they can be.
jarvild
Well-Known Member
I don't want to have a general discussion on the merits of your comments and ruin OneHitDone's thread so I'll keep it short on this thread
I think the general accepted rule for running a led garden is 80-85F for ambient temps (unless your running IR). So what's the losses do you figure when you plug that data into your calculations?
Do you have specific test or documents showing this?
Anyways, it's a shame we can't have an adult conversation without all the rhetoric that goes on.
OneHitDone
Well-Known Member
You have just made the case yourself for what I consider the single biggest issue with ALL LED for plant lighting. Out in the real world and not just talking about a cannabis grow room where the infrastructure has been implemented to have perfect climate control - led thus far has shown to be an inferior light source to other tech.
I am talking about the average home gardener that just wants to plug in a light over some herbs on the kitchen counter. Other techs rock it out but your saying I need to crank the furnace up to 80-85 to get proper results from the led?
And to clarify @HydroGrowLED is clearly confident in having me run the fixture with no fan for temp testing but this thread isn't going there.
I'm not playing pretengineer on the fixture.
All I want to see is out of the box how this baby grows
HydroGrowLED
Well-Known Member
Temperature (regardless of what light you grow with) affects your overall yield and growth rate. CO2 further increases the rate of photosynthesis and the difference in growth achieved at various temperatures. The higher temperature you run for a plant (to a certain point), the faster it will undergo photosynthesis (grow). Ideal temps for most plants without CO2 enrichment is about 80F. With CO2 enrichment the ideal temp shoots up to 95-100F.
The radiant heat from a fixture will determine how high your ambient temp can be without harming the plants. As HIDs and CFLs produce a decent amount of IR heat, it is more difficult to run a hotter room as the plants are combating the radiant heat from the fixture in addition to the ambient heat in the environment. With LEDs you don't have IR (radiant heat), which means you can achieve higher ambient temps without stressing your plants. If anything I see this as an advantage because with LED you can run hotter, allowing for faster rates of photosynthesis (more growth in less time).
You don't have to crank the temps up, but doing so will increase the growth rate of your plants up until about 80F without CO2 enrichment. Considering your room is at 75F, you're pretty close to optimal already.
jarvild
Well-Known Member
Last reply here.You have just made the case yourself for what I consider the single biggest issue with ALL LED for plant lighting. Out in the real world and not just talking about a cannabis grow room where the infrastructure has been implemented to have perfect climate control - led thus far has shown to be an inferior light source to other tech.
I am talking about the average home gardener that just wants to plug in a light over some herbs on the kitchen counter. Other techs rock it out but your saying I need to crank the furnace up to 80-85 to get proper results from the led?
And to clarify @HydroGrowLED is clearly confident in having me run the fixture with no fan for temp testing but this thread isn't going there.
I'm not playing pretengineer on the fixture.
All I want to see is out of the box how this baby grows
Have a good grow and I mean that from the heart.
SSGrower
Well-Known Member
The 1st lense over your led is trapping a significant amount of heat. OHD is measuring a surface temperature of the 2nd lense. That heat is also degrading you pmma, reducing output even faster vs. unlensed. More parts more problems, if you arent boosting drive current to meet output for a desired 2 dimensional footprint then you arent creating that additional heat either. Compounding effects.Sweet deal! Nice little addition for the time being considering there is so much lit area that isn't growing anything
Our LEDs are run at 600mA last I checked. We ran them at 550mA for years and did bump the amperage to 600mA, but this had nothing to do with lens loss (as we've been running the Xlens since 2011). It had to do with the LED chips becoming more stable over time at higher drive currents resulting in less loss of output. For what it's worth, PMMA has a loss of about 7%, which is made up for by the fact that we are delivering nearly 100% of our light within our desired coverage area (whereas competitors often waste about 20% of their light on walls without using lenses). I'd call it a pretty smart trade-off, but you might disagree.
Despite our drive current, the heat sink is reading at 5 degrees above ambient level, and the lens is reading at 10 degrees above ambient.
You'll see in the graph above the light decay of red, blue and white LEDs based on temperature. 25C (77F) is the point at which we classify the LEDs at 100% output and is considered the optimal operating temp. Our LEDs are operating somewhere between 80-85F, which would result in about a 3-5% loss of initial output (for red) according to the graph (which isn't specific to any one manufacturer and is at least 5 years old). The blue and green LEDs on the other hand would be operating at 98-100%.
I'm not sure where you are drawing the conclusion that we are creating more heat which is shortening the life and reducing efficiency, considering we have one of the lowest operating temps in the industry (by design). With that said you are still welcome to disagree with me and maintain your own opinions.
Now lets let OHD grow his lettuce.
OneHitDone
Well-Known Member
I believe I am about to slide into day 7 on this grow and I must say the plants are looking strong 
I have also added a pair of fresh lettuce seedlings to the lower left, we'll call it plant site #1 just to see how a young sprout will mature out at the corner of the coverage vs dead center under the light.
Brother OneHitDone ain't fucking around and I don't pull no punches - this test is as transparent as it gets
I have attached a screenshot of a Day 7 plant from the Cornell University Lettuce CEA Handbook for reference:
http://cea.cals.cornell.edu/attachments/Cornell CEA Lettuce Handbook .pdf
I have also added a pair of fresh lettuce seedlings to the lower left, we'll call it plant site #1 just to see how a young sprout will mature out at the corner of the coverage vs dead center under the light.
Brother OneHitDone ain't fucking around and I don't pull no punches - this test is as transparent as it gets
I have attached a screenshot of a Day 7 plant from the Cornell University Lettuce CEA Handbook for reference:
http://cea.cals.cornell.edu/attachments/Cornell CEA Lettuce Handbook .pdf
Nice, someone who knows how to use a white balance filter. I saw another thread earlier begging people not to take photos with their LEDs or HIDs on. But as you’re showing, you can take beautiful photos with the lights on. Lettuce looks nice and healthy and just where it should be at day 7 based on the Cornell handbook you posted. Cool little test man!I believe I am about to slide into day 7 on this grow and I must say the plants are looking strong
I have also added a pair of fresh lettuce seedlings to the lower left, we'll call it plant site #1 just to see how a young sprout will mature out at the corner of the coverage vs dead center under the light.
Brother OneHitDone ain't fucking around and I don't pull no punches - this test is as transparent as it gets
I have attached a screenshot of a Day 7 plant from the Cornell University Lettuce CEA Handbook for reference:
View attachment 4329280 View attachment 4329281 View attachment 4329282 View attachment 4329283
OneHitDone
Well-Known Member
Day 10 lettuce update:
I am starting to see some of the "leather leaf" type issues most led's exhibit.
I have a strong belief that the light is TOO intense at the current 16.5" recommendation. Probably about 9 mole's a day too intense.
Cannabis clone is shying away at this intensity right off the bat too.
HydroGrowLed and I have discussed it and agreed to raise the light to 24" to hit just over 200umol center par reading and observe reaction.
You can see that the leaves are not elongating out like the day 10 Cornell Reference.
I suspect it is purely too much light and we will see if there is a positive change before I move them into the nft plant sites.
I am starting to see some of the "leather leaf" type issues most led's exhibit.
I have a strong belief that the light is TOO intense at the current 16.5" recommendation. Probably about 9 mole's a day too intense.
Cannabis clone is shying away at this intensity right off the bat too.
HydroGrowLed and I have discussed it and agreed to raise the light to 24" to hit just over 200umol center par reading and observe reaction.
You can see that the leaves are not elongating out like the day 10 Cornell Reference.
I suspect it is purely too much light and we will see if there is a positive change before I move them into the nft plant sites.
boilingoil
Well-Known Member
Keep up the good work.
SSGrower
Well-Known Member
I see lots of wrinkling at the leaf margin, is this more or less than you have seen previously?
OneHitDone
Well-Known Member
Day 11 and typically the transplant day in commercial production.
I feel root development is sufficient to move to the nft channels so here we go......
You can see the lack of elongation has prevented them from sticking up very far out of the channels but hopefully the recent increase in lighting distance does the trick.
I feel root development is sufficient to move to the nft channels so here we go......
You can see the lack of elongation has prevented them from sticking up very far out of the channels but hopefully the recent increase in lighting distance does the trick.
OneHitDone
Well-Known Member
I would say fairly typical and same as previous led attempts
SSGrower
Well-Known Member
I saw cornel was doing 24hr light cycles, maintaining a minimum umol level, I didnt really see any mention of going over.
Is it your conclusion at this point you are dosing the plants with more light than the cornel study?
Do you know or would you be willing to ask if hgl ever got results for the light they sent for testing?
OneHitDone
Well-Known Member
I didn't notice 24hr being mentioned but will have to go back and read again I guess.
17 mole/day max for certain varieties was what I took away.
I think my spot intensity was too high. Cornell was also NOT using led's
I can ask about the testing lol
Pics of what under what type of lighting?
boilingoil
Well-Known Member
10-12 mols a day is more than enough for those size plants as you know. Makes you wonder if HGL herself has even grown anything period.
SSGrower
Well-Known Member
Anything really, but a white sheet of paper under daylight, under a MH or HPS, or cobs, or cfl, incandescent, t5. Just want to know what the pictures look like when forced to use the white balace for the penetrator.
A digital camera is one of the most sophisticated pieces of equipment an average person owns, we just need to trick it into telling us stories.