Which bar lights emit the least heat?

Frank Nitty

Well-Known Member
Practically-speaking, a lot of us probably use ~700W units. Someone might have multiple, but 680-720W might be a good measurement to compare. With enough feedback, we'd either see measurable differences or conclude it's hype. Newbies -- I consider myself still in this category -- may not be the best indicator. Assuming knowledgeable vets "give it a grow," posting bud pics with PAR range and efficacy benchmark, we'll have to see it to believe it.

Right now, the strongest argument for Fluence 66" Ray (the most affordable of the Rays, possibly any of their products) is that it's light, durable, and the additional 1.5' could be a scalable advantage. You'd have to assume that buying a less expensive light would mean you'd have to buy additional units to cover the same space as longer Fluence lights and/or you'd have to buy supplemental lighting to match Fluence's spectrum. Those seem like the biggest factors. I also like individual bars and ballasts, but that's almost completely a preference thing.
Thank you for putting this in layman's terms!!! So would you say that the best efficiency comes from lights that touch each corner of a tent??? Does that question make sense???
 

Apostatize

Well-Known Member
Thank you for putting this in layman's terms!!! So would you say that the best efficiency comes from lights that touch each corner of a tent??? Does that question make sense???
Awesome, thanks! Makes sense, think you're suggesting even distribution. From what I've read on RIU, bar lights are the way to go. Even those units -- already combined bars -- show a weak spot somewhere at the perimeter. A brochure may also state that the company assumes you're getting 85% bounce back from a reflective surface. Perhaps some people overcome the perimeter issue with a second unit/additional bar or some other tweak. Maybe they use 800W and change environmental factor to keep plants cool -- we'll have to see how it plays out. I'm sure experienced growers have informed opinions about that.
 
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OneHitDone

Well-Known Member
Practically-speaking, a lot of us probably use ~700W units. Someone might have multiple, but 680-720W might be a good measurement to compare. With enough feedback, we'd either see measurable differences or conclude it's hype. Newbies -- I consider myself still in this category -- may not be the best indicator. Assuming knowledgeable vets "give it a grow," posting bud pics with PAR range and efficacy benchmark, we'll have to see it to believe it.

Right now, the strongest argument for Fluence 66" Ray (the most affordable of the Rays, possibly any of their products) is that it's light, durable, and the additional 1.5' could be a scalable advantage. You'd have to assume that buying a less expensive light would mean you'd have to buy additional units to cover the same space as longer Fluence lights and/or you'd have to buy supplemental lighting to match Fluence's spectrum. Those seem like the biggest factors. I also like individual bars and ballasts, but that's almost completely a preference thing.
A lot of the selection comes down to ones grow space configuration. I used to grow on 5x5's but have scaled it back to 4x4 to conserve some floor space in my new system.
Also, the advertised SPD's by these light companies are often misleading to make the product look like something special.

Let me illustrate - HLG Scorpion RSpec

Advertised SPD
Screen Shot 2022-01-13 at 12.53.26 PM.png


Third party realistic SPD

Screen Shot 2022-01-13 at 12.53.54 PM.png

Always check the third party test data when available :peace:
 

Samwell Seed Well

Well-Known Member
A lot of the selection comes down to ones grow space configuration. I used to grow on 5x5's but have scaled it back to 4x4 to conserve some floor space in my new system.
Also, the advertised SPD's by these light companies are often misleading to make the product look like something special.

Let me illustrate - HLG Scorpion RSpec

Advertised SPD
View attachment 5066347


Third party realistic SPD

View attachment 5066348

Always check the third party test data when available :peace:
Nice

California light works had some good ones too.
Screenshot_20220113-130452_Chrome.jpg

 

ComputerSaysNo

Well-Known Member
Thank you for putting this in layman's terms!!! So would you say that the best efficiency comes from lights that touch each corner of a tent??? Does that question make sense???
The question makes sense, but not the excess of exclamation and question marks :bigjoint:

Obviously if the light coverage is optimal, with all the canopy covered but not much extra light, then that is better than having too much. If the light doesn't touch the corners of the tent it's not a problem unless there are plants growing there.

I guess this is something you can overthink, however. The light does not have sharp edges, like a shadow on the moon does.

If some plants towards the rim are not covered perfectly, they'll still receive light, but probably yield less. But the yield won't be zero.

I would rather be conservative with the lighting than going overboard.
 

Markshomegrown

Well-Known Member
A lot of the selection comes down to ones grow space configuration. I used to grow on 5x5's but have scaled it back to 4x4 to conserve some floor space in my new system.
Also, the advertised SPD's by these light companies are often misleading to make the product look like something special.

Let me illustrate - HLG Scorpion RSpec

Advertised SPD
View attachment 5066347


Third party realistic SPD

View attachment 5066348

Always check the third party test data when available :peace:
You can build your own LEDs, the right size to give your room the perfect light spread, cost me £50, bulbs cost me £100 should last 2 years(85%), as LEDs bulbs get more effective, I can use more effective bulbs, cheap to buy, cheap to run, I am loving it, my buds look much larger and more healthy under the led vs HPS, Never going to buy a led panel. my led panel will last a good 20 years (bulb holder in your lamps/walls and ceiling last what 30-40 years)
 

Attachments

Apostatize

Well-Known Member
Nice

California light works had some good ones too.
View attachment 5066351

- lighter than some, still 22lbs.
- efficacy, up to 3.5. On another page, it says 2.9. Higher than most either way
- spectrum seems lacking -- but literally just from the PAR range graph -- that's what I've mostly been comparing. A few of us have been kicking around ideas about how to measure the differences in outcome/bud quality attributable to PAR range and efficacy, individually and combined (i.e., how to determine whether the fuller "sole-source" spectrums (particularly far-red) actually improve yield/quality/potency (on top of everything else growers supplement/pump into their plants)).

- 1642121514869.png

1642121607650.png
 
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OneHitDone

Well-Known Member
You can build your own LEDs, the right size to give your room the perfect light spread, cost me £50, bulbs cost me £100 should last 2 years(85%), as LEDs bulbs get more effective, I can use more effective bulbs, cheap to buy, cheap to run, I am loving it, my buds look much larger and more healthy under the led vs HPS, Never going to buy a led panel. my led panel will last a good 20 years (bulb holder in your lamps/walls and ceiling last what 30-40 years)
Have any pictures of your rig?
Yes, Philips Par led's are awesome. There's am even nicer spectrum than that in a 17W.
Better bigger buds than hps? Not so sold on that :peace:
 

OneHitDone

Well-Known Member
You can build your own LEDs, the right size to give your room the perfect light spread, cost me £50, bulbs cost me £100 should last 2 years(85%), as LEDs bulbs get more effective, I can use more effective bulbs, cheap to buy, cheap to run, I am loving it, my buds look much larger and more healthy under the led vs HPS, Never going to buy a led panel. my led panel will last a good 20 years (bulb holder in your lamps/walls and ceiling last what 30-40 years)
This one is a real beauty

Screen Shot 2022-01-13 at 6.55.04 PM.png
 

Markshomegrown

Well-Known Member
Have any pictures of your rig?
Yes, Philips Par led's are awesome. There's am even nicer spectrum than that in a 17W.
Better bigger buds than hps? Not so sold on that :peace:
Here A picture of my LED

Led panel.JPGIMG_0751.JPG
As the lights go off, I have put 2 x3ft tube light on(timer) so I can water or take pictures, you can one shining though the led.
I turned these plants over to flower 31 days ago(12/12)

flower these off early 6" high/wide so you could say 18 days true flower(pistils start to grow).
the plants under the HPS don't look 100% buds are a little smaller and some fan leaves have curled.

buds under the LED
IMG_0745.JPGIMG_0747.JPGIMG_0746.JPG

under the HPS

under HPS.JPG
 

OneHitDone

Well-Known Member
Here A picture of my LED

View attachment 5066699View attachment 5066700
As the lights go off, I have put 2 x3ft tube light on(timer) so I can water or take pictures, you can one shining though the led.
I turned these plants over to flower 31 days ago(12/12)

flower these off early 6" high/wide so you could say 18 days true flower(pistils start to grow).
the plants under the HPS don't look 100% buds are a little smaller and some fan leaves have curled.

buds under the LED
View attachment 5066707View attachment 5066709View attachment 5066708

under the HPS

View attachment 5066706
What model bulb is it that you are using? You removed diffuser and added a reflector?
 

Markshomegrown

Well-Known Member
What model bulb is it that you are using? You removed diffuser and added a reflector?
13w led.png
you can buy packs of 10 on amazon for £32
I also added 4 4000k 12w led bulbs (same as bulb above, just the 4k version)
I used mylar and cut it into a comb shape, stuck it with double-sided tape, fits like a glove
 

ComputerSaysNo

Well-Known Member
@Markshomegrown I love the idea, so obvious yet so few people are doing it. I've seen one video where a guy made a vertical grow in his basement (not cannabis, mostly leafy greens), and he also used regular LED bulbs from a hardware store.

Also I don't see why the performance from a self-made array of LED bulbs should be much different from a commercial grow light. You even have flexibility of manipulating the spectrum by putting in bulbs of different color temperatures.

Some quick maths (in Euros):
  • Standard E27 socket around €2
  • LED bulb 11W around €2 (this varies, can be even cheaper); let's say 0.2€/W
  • not much else needed in terms of materials
That means per 100W from 11W bulbs one pays €50 tops, and then there is a lot of flexibility for how to configure the array. This is a lot cheaper than regular grow light LED boards (or bars).

I've snatched a 100W Mars Hydro at Amazon for around €75 a while ago, and that already felt like a complete steal to me. This solution here is even cheaper by a margin.

It's possible to have single bulbs cover dark corners, very easy to make a vertical setup etc.

Some downsides that come to mind:
  • Dimmable bulbs are a lot more expensive, and then a quantum board is cheaper. Varying light intensity has to be achieved by making parts of the bulb array switchable.
  • Possibly the quantum boards have a better spectrum for growing. I would really like some definitive information if this is true. Right now I don't think the difference is that big; it would have to be quite the difference in efficiency for it to matter (say, 20%?)
  • DIY required, bulb heads have to be shaved off for maximum efficiency, messing with electric installations can be dangerous.
  • More bulky than a quantum board.
Right now I'm glad that I haven't invested a lot in regular LED lights as of late, because this is so much cheaper, I really need to try this.
 

ComputerSaysNo

Well-Known Member
Quite relevant to the above, here is a very informative video of somebody building an array of LED bulbs and doing precise measurements on the efficiency.

It's striking how much it helps to cut the diffusers off the bulbs.

He gets around 1.8 umol/J efficiency; really good in my opinion.

 

Apostatize

Well-Known Member
Small plant, lollipopped. Low yield but happy with bud shape, size, density, frost, taste, appearance, and smoke. A little rough on the grinder.

elev8's Gorilla Cookies from clone:
IMG_20220114_105336.jpgIMG_20220114_105315.jpgIMG_20220114_105315.jpg
 
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