Top bin COB comparison

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littlejacob

littlejacob

Well-Known Member
Bonjour
Wow diy a driver...you play at another level!
And yes V29 are good cob too!
How many amp an output voltage will be your 800w driver?
It will be for a parallel wiring I guess!
CU
 
K

ketchup45685224

Well-Known Member
littlejacob said:
Bonjour
Wow diy a driver...you play at another level!
And yes V29 are good cob too!
How many amp an output voltage will be your 800w driver?
It will be for a parallel wiring I guess!
CU
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We'll see about a playing at a different level until after I have it build and working. :) The app notes are really good and math isn't to hard.
I planning on 420 max forward voltage and adjustable current from 500 mA to 2500 mA
 
satdom

satdom

Well-Known Member
ketchup45685224 said:
I'm planning at building my own driver. TI has some really good app notes for their UCC28180 PFC controller. I think by changing the feed back loom. It'll make a great high voltage constant current driver. I done some adding of parts and PCB. I think, I can build 800 watt one for about $75 to 100. I'm not welded to the idea of using the cheap LEDs. But, I do not think it's unlikely I'll go with Crees. I not a hobby grower and sending over a grand to replace one 1000 watter seems crazy. I have some Vero 29's aready and from what I've seen they're a great value. I will be doing some testing and comparing between the cheap leds and the Vero 29s before going ahead with anything. I should be able to build a test rig get the testing done in the next couple of weeks.
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If you're a professional and you look at the cost of electricity, cooling, quality of product etc, I'd be highly surprised if CXB top bin wasn't the only choice.


The kicker is this was the old lights and the new lights (CXB3590) kill in every metric. Even gm/ft^2.


Thank growmau5 for amazing work in documenting...
 
K

ketchup45685224

Well-Known Member
satdom said:
If you're a professional and you look at the cost of electricity, cooling, quality of product etc, I'd be highly surprised if CXB top bin wasn't the only choice.


The kicker is this was the old lights and the new lights (CXB3590) kill in every metric. Even gm/ft^2.


Thank growmau5 for amazing work in documenting...
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It's the cost upfront that kills it. He spent 2400 bucks to cover a 32 ft2 space.
 
SupraSPL

SupraSPL

Well-Known Member
ketchup45685224 said:
I'm not welded to the idea of using the cheap LEDs. But, I do not think it's unlikely I'll go with Crees. I not a hobby grower and sending over a grand to replace one 1000 watter seems crazy.
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Up front cost can definitely be a deterrent especially if you have not seen what COBs can do first hand. But if you are pounding 32 sq ft of grow space you are going to get a huge yield of dank, at least 2 pounds per cycle and maybe even 3-4.

@Growmau5 $2500 cost was to build with CXB3590s running at 25W ea (estimated 64% efficient). I use the same design at 25W ea and love it, but that may be for enthusiasts, experiments or those whose production is directly heat limited.

I do believe @satdom is correct, from a cost benefit analysis when it comes to indoor lighting I am not sure there is a better "one size fits all" configuration in existence than the (4) CXB3590 @ 50W ea (56% efficient) with HLG-185H-C1400 driver. @Growmau5

To cover 32 sq ft at 50W ea and get 750 PPFD averaged:
(20) CXB3590 $900
(5) HLG-185H-C1400 $275
(5) 3.5"X36" heatsinks w fan $250
(20) Holders/adapters/reflectors $80
Total $1500 shipped + your labor to assemble
543W waste heat

To cover 32 sq ft with HPS and get 950 PPFD averaged initial intensity:
(2) 1000W DE $425 ea
Total $900 shipped + bulb and reflector replacement every year
1500W waste heat

DE HPS Pros:
Save a few bucks up front
Quick easy setup
Thoroughly proven good results

DE HPS Cons:
triple the waste heat from the fixture overall
increased air conditioning cost
possible loss of productivity due to heat handling limitations in certain seasons
double the electrical cost for the lamp
reduction of stealth due to massive air movement/ducting/noise/smell
possible reduction in bud density, flavor, potency due to slightly higher canopy temps
extended flowering cycles due to canopy temps or immature harvest if cut too soon
significant cost of inline fans, ducting and fan electrical use
decreased space due to extensive ducting
increased heat due to inline fan motors
 
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SupraSPL

SupraSPL

Well-Known Member
bassman999 said:
Thanks for that breakdown. I looked at the graphs on their respective Vf as they go up in current. I was wondering if something like this was the reason.
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You are correct, the fact that the 3070 dies are running harder explains why the 3070 is a higher Vf than the 3590. The Vf change is accounted for in the efficiency spreadsheets and in the PAR comparison current droop curves posted earlier.
 
SupraSPL

SupraSPL

Well-Known Member
ketchup45685224 said:
I've seen some of those videos as well. I have some of those cheap leds and they all light up when the current is high enough. Are they as good as the name brand ones. NO. But, I'm going to see how cheap, I can build a light that replaces a 1000 HPS with LEDS.
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I have seen the generic 100W COBs for as little as $4 ea but then again Vero10 is only $4. I would like to test a generic 100W COB and see how it stacks up (correction factor will be a fudge factor but I'll give it +5% for warm white.)

There are some unexpected cost increases when running LEDs that are relatively low efficiency. It requires more heatsink, driver, lens, reflector, wiring, labor etc to do the same job, so that extra cost partially offsets the cost of using higher efficiency COBs. Then of course there is the extra electrical cost and air handling cost.

But all that said, it is harder to make the case for high efficiency LED (CREE) vs lower efficiency LED (VERO) than it is for LED vs HPS. I had good results from 26% efficient LED back in 2010, although it was a PITA to assemble from single diodes, it was well worth it.
 
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wietefras

wietefras

Well-Known Member
You don't need two of those Gavita pro fixtures for that space. One could work to for a PPFD of 650 to 700umol/s/m2. Or if you want to keep the PPFD up, use the 750W version. You don't need to change the bulbs every year either. The DE bulbs keep their output for much longer.

1500 waste heat seems a bit high too. DE bulbs are 39% efficient (that's much higher than the 36% of a regular HPS bulb). If not more. They produce 2.1umol/s per watt. That's not far off from the 2.2umol/s/W that you get from a CXB3070 at 1.4A.

I have worked with these Gavita Pro fixtures. They really are amazing lights if you use them properly. I like my Cree COBs better, but the difference isn't as big as that example would imply.
 
SupraSPL

SupraSPL

Well-Known Member
wietefras said:
You don't need two of those Gavita pro fixtures for that space. One could work to for a PPFD of 650 to 700umol/s/m2. Or if you want to keep the PPFD up, use the 750W version. You don't need to change the bulbs every year either. The DE bulbs keep their output for much longer.

1500 waste heat seems a bit high too. DE bulbs are 39% efficient (that's much higher than the 36% of a regular HPS bulb). If not more. They produce 2.1umol/s per watt. That's not far off from the 2.2umol/s/W that you get from a CXB3070 at 1.4A.

I have worked with these Gavita Pro fixtures. They really are amazing lights if you use them properly. I like my Cree COBs better, but the difference isn't as big as that example would imply.
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Important points you raise. The reason I suggest 2000W HPS in a 4X8 is to make the point, to match the yield of 1000W CREE COB, that is what it would take to get the job done.

This is how I figured the waste heat for a pair of Gavita 1000W DE:
2105W power draw, 105W ballast heat
2000W bulb dissipation @ 40% = 800W light, 1200W heat
800W light - 20% reflector loss = 640W light, 160W heat
640W light - 5% wall loss = 608W light, 32W heat
Total waste heat = 1497 Watts

For the COB setup:
1052W power draw, 52W driver heat
1000W dissipation @ 56.3% = 563W light, 437W heat
563W light - 10% lens/reflector/wall loss = 507W light, 56W heat
Total waste heat = 545 Watts

The 2.07umol/s/W figure sometimes mentioned by Jair/Whazzup/Gavita is probably including photons outside of the PAR range. In April 2014 Bruce Bugbee tested both the Gavita Pro and Epap lamps at 1.7umol/s/W, in an integrating sphere with ballast losses included, putting output of the 1000W DE bulb at 1.79/umol/s/W or 38.4% efficient (initial). The CXB3590 3500K CD @50W is ~2.62umol/s/W from 400-700nm or 56.3% efficient.

The reason I mention the annual DE bulb and reflector change, that is the recommendation of Jair from Gavita. He says loss of 3-5% every year. I have never tested the degradation of a reflector myself, but it does make sense, the bulb very much depends on the reflector to get light to the canopy (60-70%). So any dust or film that accumulates on the reflector will have a very significant impact on PPFD. That is why Gavita designed with a relatively cheap reflector and supposedly it is a very quick job to swap it out.

Jair interview on Adam Dunn show starts at about 1:02:00
 
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K

ketchup45685224

Well-Known Member
SupraSPL said:
Important points you raise. The reason I suggest 2000W HPS in a 4X8 is to make the point, to match the yield of 1000W CREE COB, that is what it would take to get the job done.

This is how I figured the waste heat for a pair of Gavita 1000W DE:
2105W power draw, 105W ballast heat
2000W bulb dissipation @ 40% = 800W light, 1200W heat
800W light - 20% reflector loss = 640W light, 160W heat
640W light - 5% wall loss = 608W light, 32W heat
Total waste heat = 1497 Watts

For the COB setup:
1052W power draw, 52W driver heat
1000W dissipation @ 56.3% = 563W light, 437W heat
563W light - 10% lens/reflector/wall loss = 507W light, 56W heat
Total waste heat = 545 Watts

The 2.07umol/s/W figure sometimes mentioned by Jair/Whazzup/Gavita is probably including photons outside of the PAR range. In April 2014 Bruce Bugbee tested both the Gavita Pro and Epap lamps at 1.7umol/s/W, in an integrating sphere with ballast losses included, putting output of the 1000W DE bulb at 1.79/umol/s/W or 38.4% efficient (initial). The CXB3590 3500K CD @50W is ~2.62umol/s/W from 400-700nm or 56.3% efficient.

The reason I mention the annual DE bulb and reflector change, that is the recommendation of Jair from Gavita. He says loss of 3-5% every year. I have never tested the degradation of a reflector myself, but it does make sense, the bulb very much depends on the reflector to get light to the canopy (60-70%). So any dust or film that accumulates on the reflector will have a very significant impact on PPFD. That is why Gavita designed with a relatively cheap reflector and supposedly it is a very quick job to swap it out.

Jair interview on Adam Dunn show starts at about 1:02:00
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You make a very compelling case for the LEDs. If one can get a 63% reduction in heat need roughly half the installed watts, that would be awesome. I'll have to build something and see it with my own two eyes. I don't doubt they work gram/watt. But can I get the same density and quality as 1000 watt HPS?
 
Malocan

Malocan

Well-Known Member
wietefras said:
You don't need to change the bulbs every year either. The DE bulbs keep their output for much longer.
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"High light maintenance: >95% per year so you only need to change your lamp once per year"
That is what Gavita writes about their Bulbs.
Last year i bought a Gavita Pro6/750e DE Flex Eu, the experience with that Lamp fixture after 6-9months was horrible.
In compare to a normal HPS(same watt amount like gavita) you have to hang the Gavita much higher above the plant canopy.
And the amount of heat which the lamp produce with help of that little reflector is unbelievable.
After my experience with different lights, i would claim its much harder to grow under a Gavita in compare to LEDS.
 
Rahz

Rahz

Well-Known Member
SupraSPL said:
I do believe @satdom is correct, from a cost benefit analysis when it comes to indoor lighting I am not sure there is a better "one size fits all" configuration in existence than the (4) CXB3590 @ 50W ea (56% efficient) with HLG-185H-C1400 driver. @Growmau5
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As soon as the 240H-C becomes more available I suspect a lot of people will be using the 1.75 amp version with 4 CXB3590s. $10 more for an additional 48 watts. Efficiency drops from 56 to 53 but still impressive.
 
Greengenes707

Greengenes707

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KarmaPaymentPlan said:
it was an easy upgrade i scored 2!
got to match the old drivers with some fresh 3070s thanks GG
I'm hoping by the time i score the new 2100 hlgs for my Veros, PLC will have more chips in stock!
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Ya, there real nice. I have been using the hlg240-36's for a while before the strictly constant current versions were made and have designs coming based on them. So the new C's just fit right in for me...instead of me having to fit into it. That is as hard as I want to drive my lights though. Clearance:coverage is already an issue running relatively soft, so more power per point source in a non-commercial setting is tough for me to get behind. But less components is aways cool for the extra budgeted DIY builds

Jan 10th ship date from cree for more 3070's. End of jan(hopefully sooner) for 3590's(45$). All you guys are cob animals...flew out the door.
 
SupraSPL

SupraSPL

Well-Known Member
ketchup45685224 said:
You make a very compelling case for the LEDs. If one can get a 63% reduction in heat need roughly half the installed watts, that would be awesome. I'll have to build something and see it with my own two eyes. I don't doubt they work gram/watt. But can I get the same density and quality as 1000 watt HPS?
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I have never grown with more than a 600 HPS although I have seen many of my friends grows that 1000W air cooled and we have run the same cuttings. In my experience the bud density is higher under COB due to potentially higher PPFD and lower canopy temps. This also results in a quicker finish which I really appreciate.

One thing I disagree with Jair about is the ideal canopy temp. He suggest that if you run the canopy too cool you will lose photosynthetic efficiency and when it comes to veg I agree, but when it comes to the final 6 weeks of flower if I allow warm canopy temps I get less frosting, flavor, potency, density and it can take an extra week an a half to finish. So I try to keep canopy temps under 80F and I dim the COBs in the final week.
 
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