Is anyone coming from 1000w mh/hps that is getting similar or better results with LEDs?

Mathimus

Member
I would like to add that heat is not a big issue with air cooled HID lamps, thus will not put out the same amount of heat as an LED. I'm not arguing that 600 watts of HPS power runs cooler than 600 watts of LED power. However, if they are closed hoods, ducted and being cooled by an external fan on the outside of the room, 600 watts of HPS power runs significantly cooler than 600 watts of LED power.

The LED industry is misleading by claiming LEDs put out little or no heat. Many purchase these lights and are hoodwinked into thinking heat will not be an issue because of seeing misinformation concerning LEDs not putting out heat. Just wanted to clarify what I meant in my original post.
 

ANC

Well-Known Member
Understand. I think I'm just spoiled from running air cooled hoods. I ran 2 ducted 1000w digilux at full blast with a hyper fan at no more than 60% power and could put my hand on the bottom of the glass or anywhere on the fixture, as it was only warm. I guess my quandry with LEDs is they don't have the ability to be cooled in such a way.
My LED fixtures get maybe up in the high 40C area, it is soooooo far from an HID it isn't funny....

Most growers will have to add heat in winter, to have optimal results, you can use the cheapest heater, they all have the same power limit at the wall as the expensive ones, get a good controller and work on your insulation.
 

Dr. Who

Well-Known Member
This is not true. If it were, then there would be no such thing as energy efficient light bulbs. The reason incandescent bulbs are less efficient than CFL and LED is because 90% of the energy used to illuminate incandescent bulbs is going out to the heat produced by the bulb. I think you are confusing the fact that less watts = less heat.
You posted this kinder then I would have, to follow up on his poorly understood claim.
Made my life easier
 

Mathimus

Member
Yes, i am getting better results all around using led now. Took a minute but am jamming like never even thought possible.
Here's some on my locked thread.


Just got through reading the thread. What a read. I horse laughed when the guy said bukakke of LED spectrums. Bit of a cliffhanger at the end. I guess that's why some read the end of the book first. I'm digging the fact you can spread those out and angle them different ways. That's one issue I had with hoods and my vertical space being restricted on the spread. My flower area is an enclosed 6x13 x81" tall so a bit height restricted. I'll be working from below as well under a scrog. Some questions:

When you were measuring temps on the front, back and side of the unit, was that surface temps of the unit or the ambient temps around the light? Were those readings taken at full power?

Is the unit modular? Can the bars be removed and mounted to something else independently while still daisy chained together? I couldn't tell if the 2-bar lights in your pics were from the 8 bar or something entirely different.

What's your overall opinion on penetration? Did stuff seem any more larfy or dense that would normally be larfy on the lower part of the canopy using HID?

Did you feel that you used more or less cooling/exhaust effort than running sealed air cooled hoods? Do you get hotspots under the units? Did you use full power during flower or not so much? What was the happy height range above the canopy in flower that you found prevented light burn but promoted the most growth?
......

I think I've narrowed it down between this or the newer chilled bar light. I wondered about solis tek but they have took the piss it seems. Their built in timer ballasts were top notch with the daisy chain one remote control. They seemed to be on the pinnacle of lighting tech a few years ago and then poof...Thanks for your input!
 

Kassiopeija

Well-Known Member
With LED it actually makes sense to have a vent above it and cool it by blowing the warmth down below at the canopy. It better works with a layout stripped like Sylvania Grolux than Quantum Boards.

Avg. leaf temps:
LED: -2
HPS: +6
(important for VPD)

One can also place the LED board closer to the plants than with HPS. This - plus the multi-angular source of beams - greatly increases canopy penetration. It also diminishes the middle heat spot a bit.
 

Mathimus

Member
With LED it actually makes sense to have a vent above it and cool it by blowing the warmth down below at the canopy. It better works with a layout stripped like Sylvania Grolux than Quantum Boards.

Avg. leaf temps:
LED: -2
HPS: +6
(important for VPD)

One can also place the LED board closer to the plants than with HPS. This - plus the multi-angular source of beams - greatly increases canopy penetration. It also diminishes the middle heat spot a bit.
In my experience, I've not seen anyone placing high output LEDs close to the canopy. Maybe some lower power ones. Some of my flowers have been 15" below the light with hps and never had problems because they are cooled. Sometimes closer. That's been unintentional due to limited headspace and some stretching that I underestimated.

I couldn't see blowing the heat down on my plants from the LED unless I was looking to supplement heat. I'm trying to keep my heat down. My exhaust is sucking through a ducted filter on the inside upper left, with the intake coming through a vent on the lower right. Thus air is circulated in a diagonal from right to left.

I have seen quantum boards in action and those things get hotter than a two dollar pistol shooting ghost peppers at a BP oil rig in 2010.
 

ANC

Well-Known Member
With LED it actually makes sense to have a vent above it and cool it by blowing the warmth down below at the canopy. It better works with a layout stripped like Sylvania Grolux than Quantum Boards.

Avg. leaf temps:
LED: -2
HPS: +6
(important for VPD)

One can also place the LED board closer to the plants than with HPS. This - plus the multi-angular source of beams - greatly increases canopy penetration. It also diminishes the middle heat spot a bit.
You may be on to something but my fan pretty much sucks the tent in so no heat really gets to build up.
Sealing it up with a few CO2 bags might work better for winter. I need to pester my buddy who just started up a myco bag company before lockdown, we were literally like 3 days away from the expo.
 

ANC

Well-Known Member
In my experience, I've not seen anyone placing high output LEDs close to the canopy. Maybe some lower power ones. Some of my flowers have been 15" below the light with hps and never had problems because they are cooled. Sometimes closer. That's been unintentional due to limited headspace and some stretching that I underestimated.

I couldn't see blowing the heat down on my plants from the LED unless I was looking to supplement heat. I'm trying to keep my heat down. My exhaust is sucking through a ducted filter on the inside upper left, with the intake coming through a vent on the lower right. Thus air is circulated in a diagonal from right to left.

I have seen quantum boards in action and those things get hotter than a two dollar pistol shooting ghost peppers at a BP oil rig in 2010.
I have been doing the high output close to the canopy thing... it reduces leaf size and leaves were often two-toned lime and yellow, jut not being able to keep up. Then I saw one of my clients run his way up in the tent and getting nice big leaves like I normally do ( I'm new to tents). Well duh, I went to check with what I had at hand and it was about 70000lux at canopy levelsIMG_20200429_163037.jpg
 

Ted2015

Member
Never used HPS but know people who have with varying degrees of success. I use 4 LED units drawing around 1500 W total, the theory is they replace 2 x 1000 HPS. I doubt I could get better with HPS. I like the light coverage and heat distribution on my units. Different LED configurations have very different results I think. My DIY LED units have drivers sitting outside the tent, the diodes are separated and space out on individual heat sinks. I do have a spiderfarmer 4000 as well and that gets much hotter with the drivers attached to the back inside the tent and everything bunched up together, light intensity is better but coverage is not as good and everything gets hotter above and below. Mine are a bit high right now for my widow but they are still doing very well, the candy is a bit leggy thus lights higher than optimal, at the correct distance from plants getting easy 70k lux top across the entire canopy and 30-50k throughout down to pot height. I am not sure if LED are better than HPS but i think they are definitely more versatile and work just as well. Looks like very dense buds as well, but proof will be in the pudding as this is my first grow.
 

Attachments

Kassiopeija

Well-Known Member
In my experience, I've not seen anyone placing high output LEDs close to the canopy. Maybe some lower power ones. Some of my flowers have been 15" below the light with hps and never had problems because they are cooled. Sometimes closer. That's been unintentional due to limited headspace and some stretching that I underestimated.
air cooling only removes convective heat - which a HPS has much, yes, but the distance the lamp should be based upon the flux density of photons. the math is this case is clear - you throw 1000w through a single source and you'll get a sphere of light around that point with increasingly less strength.
Rule of thumb for HPS is actually 100w = 10cm distance. If you go nearer plants can foxtail, get lightbleached or heatstressed.

However, HPS can get old and be diminished from 150lumen/w to 100 in short time - whereas LED stays at 200 lument/w, its essentially releasing twice the amount of photons at your plant at the same power intake from the wall.

Now if you drive such a rack at 50% so it turns out the same amount of light than a 1000w HPS, then you can ofc have it nearer because the same amount of photons are released by 500-1000 sources instead of just 1 source.


edit:
HID-lamps.png
from this sheet you can gather alot what distance does to your growlight. if you go to close the lightstrength reaches insane heights. this is because of the physical laws which is applicable to singular light sources, but actually your reflector will influence these numbers, so you'll have to see for yourself.
 

Kassiopeija

Well-Known Member
BTW a hooded reflector doesn't spread out the light so good as an open-winged one and therefore creates a much stronger central heat spot - that's why you need to place hooded reflectors more far away than winged. Otherwise your center or top plants get burned and the side plants lack light... and then you have this typical pic with the tops all yellow bleached and the side bottom leave dark green... but in nature most leaves get always the same lightstrength it doesn't matter how high the leave hangs...
 

Mr. Cheetah

Well-Known Member
Just started using 2 roi680e's a couple months ago havent had a harvest off them yet. I have a couple pretty reliable sources telling me with all other factors being in check and a good producing strain to expect upwards of 3 lbs per fixture with co2. Realistically I'm hoping for somewhere between 1 and 2 with how I have things set up. Seems like pretty good fixtures as long as height isn't an issue.
daymn, i miss scrog
 

ANC

Well-Known Member
However, HPS can get old and be diminished from 150lumen/w to 100 in short time - whereas LED stays at 200 lument/w,
LED's do in fact lose some output over time, we have not been tracing it very long as they are pretty new, but the good Samsungs lose about 7% the first year... that is about as far as testing is now.... more date to be added.
 

FADING-SILHOUETTE

Well-Known Member
BTW a hooded reflector doesn't spread out the light so good as an open-winged one and therefore creates a much stronger central heat spot - that's why you need to place hooded reflectors more far away than winged. Otherwise your center or top plants get burned and the side plants lack light... and then you have this typical pic with the tops all yellow bleached and the side bottom leave dark green... but in nature most leaves get always the same lightstrength it doesn't matter how high the leave hangs...
A parabolic reflector is better still... - STELTHY :leaf:
 

Kassiopeija

Well-Known Member
LED's do in fact lose some output over time, we have not been tracing it very long as they are pretty new, but the good Samsungs lose about 7% the first year... that is about as far as testing is now.... more date to be added.
yeah that's true, and I think the temperatur under which the diodes operate can influence this degradation a little... it gets worse with UV and its hard to trust the life expectancy numbers of the manufacturers.

The surface seems also more prone to damage from sprinkle water salts or else... tbh I heavily dislike that a diodes creates such a strong spot of light, if you sort of protect your eyes really well and look close into a single diode you may observe this pin of extreme light. If too close it can create light spots on leaves...

A HPS doesn't look so bright because the human eye is so much more sensitive to green than yellow/red - so a lot of folks anticipate from the own view they can let the plant grow very close. For example, on my 600w HPS Sylvania Grolux the data sheet explained "92.000 lumen" but the package: "200.000 phytoLumen" to indicate the light from this lamp is so much more "light" for plants than for us...
 

ANC

Well-Known Member
My 550 does about 92000 lumens in theory, but they are at least all pointed in the floor's general direction, unlike a bulb where 50% starts out going the wrong way. I also went with a larger footprint and 25% more diodes than the original HLG 550 for my design. Each strip is 288 diodes.

lIMG_20200206_115721.jpg
 

Kassiopeija

Well-Known Member
My 550 does about 92000 lumens in theory, but they are at least all pointed in the floor's general direction, unlike a bulb where 50% starts out going the wrong way. I also went with a larger footprint and 25% more diodes than the original HLG 550 for my design. Each strip is 288 diodes.

View attachment 4562152
yeah man this is a good design to blow the heat towards the leaves to cool the lamp, distribute heat and compensate the -2 temp loss from transpiration. and then its more wide than long (or the other way round donno lol) so you can fit into more setups.

it's also good that the diodes are spread apart. one of the weaknesses of HID is the central lightsource. I'm using wings & underlaying spreader to combat that in one of my HID lamp but it always comes at the cost of luminosity + increased heat + changed spectrum.

LED can do away with this weakness by design, placement of diodes. However, I have not seen any ppfd layout which was able to fully eradicate the center hotspot. For that, it seems like there shouldn't be diodes placed at the center rack....

The reflected light from a hood diminishes in strength, depending on material -3% to -30% leaving the loss always as heat. Some light pathways bounce multiple times and then add only very miniscule to the general luminosity.

How much minimum distance do you recommend for this light to the upper canopy? What about individual high shooting colas?
 
Top