New COB LED Design & Comparison

Hey everybody, it's been a long time since I've posted here but I've been playing around with some COB tech and want to put it out there for all to scrutinize and enjoy.

The setup is 4 CXB3590 80cri 36v with 18" center-line spacing.
I have these 36v CXB's driven hard @ 2.8 amps while being actively cooled and case temperatures not exceeding 60*C (140*F).
Total power consumption is ~560 watts after the LED's come to temperature.

I designed the system to have a 4x4 coverage area with an even spread of light. (see attached image)

All PPFD measurements were taken using an Apogee Quantum Sensor.

Here are a few pictures of the case design and the active cooling system.








Please let me know your thoughts.

GreenLED said:

Hey everybody, it's been a long time since I've posted here but I've been playing around with some COB tech and want to put it out there for all to scrutinize and enjoy.

The setup is 4 CXB3590 80cri 36v with 18" center-line spacing.
I have these 36v CXB's driven hard @ 2.8 amps while being actively cooled and case temperatures not exceeding 60*C (140*F).
Total power consumption is ~560 watts after the LED's come to temperature.

I designed the system to have a 4x4 coverage area with an even spread of light. (see attached image)
View attachment 3752190
All PPFD measurements were taken using an Apogee Quantum Sensor.

Here are a few pictures of the case design and the active cooling system.

View attachment 3752194 View attachment 3752196
View attachment 3752197
View attachment 3752198
View attachment 3752199
View attachment 3752201
View attachment 3752203

Please let me know your thoughts.

Click to expand...

You my friend, are the only person I've ever seen drive 3590's that hard. It's crazy to think 560watts from 4 cobs!?that's 140 watts each. Basically at the breaking point. Insane. You can see how bright it is though dam. Your spacing is on point. I bet that light would fuckin kill it.

I think he's accounting for the fans and extra driver for them.hope that sucker has a dimming knob lol.nice work

nice looker. details on the metal case? where does intake air come in?

Airwalker16 said:

You my friend, are the only person I've ever seen drive 3590's that hard. It's crazy to think 560watts from 4 cobs!?that's 140 watts each. Basically at the breaking point. Insane. You can see how bright it is though dam. Your spacing is on point. I bet that light would fuckin kill it.

Click to expand...

its 104W/cob and i guess 36W of driver loss and i guess 120W in fans

those numbers dam, TBH how hard is it to change a chip anyways, pop a clip a screw and put in a new chip, twist the lens back on.

I wanna see how these run, though a cycle. veg--->flower

CobKits said:

nice looker. details on the metal case? where does intake air come in?

Click to expand...

Hm I didn't notice this. You need to add some holes drilled in the sides to aid in air flow. I assume your big fan is pulling air from inside the fixture, up, and out, right? I guess that's probably the best way to go about it with having cpu coolers. They're already pulling air down and onto the heatsink and being forced off the sides which in turn the big fan takes that heat and exhausts it out through the top. But if you were to add some holes in the sides, I really think it would aid in your cooling quite a large amount by allowing fresh cooler air to be pulled in to allow that hotter air building up inside to be taken out. Hope to hear back from you.

g'day @GreenLED

Neat case
& are those 3500k COBs
VG

How far from the plants would these have to be placed?

CobKits said:

nice looker. details on the metal case? where does intake air come in?

Click to expand...

It's hard to see from the pictures but there is a slight gap where the panels overlap. This is the only place at the moment for fresh air draw. More cooling holes can be added as needed. Good eye!

CobKits said:

its 104W/cob and i guess 36W of driver loss and i guess 120W in fans

Click to expand...

Very close, fan draw is ~80W.

SoOLED said:

those numbers dam, TBH how hard is it to change a chip anyways, pop a clip a screw and put in a new chip, twist the lens back on.

I wanna see how these run, though a cycle. veg--->flower

Click to expand...

Chips are very easy to change, I wanted this light to be easily serviceable. All you need to do to change a chip is pop off the lense by pulling the CPU fan releases that hold the lenses on the assembly, remove the 2 screws and replace the COB. Takes less than 5 mins.

Airwalker16 said:

Hm I didn't notice this. You need to add some holes drilled in the sides to aid in air flow. I assume your big fan is pulling air from inside the fixture, up, and out, right? I guess that's probably the best way to go about it with having cpu coolers. They're already pulling air down and onto the heatsink and being forced off the sides which in turn the big fan takes that heat and exhausts it out through the top. But if you were to add some holes in the sides, I really think it would aid in your cooling quite a large amount by allowing fresh cooler air to be pulled in to allow that hotter air building up inside to be taken out. Hope to hear back from you.

Click to expand...

Good idea, I will look into adding some extra holes for added cooling.

verticalgrow said:

g'day @GreenLED

Neat case
& are those 3500k COBs
VG

Click to expand...

Thank you! The COB's are 5000k for now my goal was for an even full spectrum white light, after seeing other people's success on here with the 3500K I'm open to change.

Uberknot said:

How far from the plants would these have to be placed?

Click to expand...

The lights are designed to be placed 18" above the canopy.

Thanks again everybody for all your feedback!!

ill bet your fan load drops when you open up some airflow, its fighting itself right now

CobKits said:

ill bet your fan load drops when you open up some airflow, its fighting itself right now

Click to expand...

I bet you're right, I would have to agree the fan system is fighting itself. Any ideas on where the hole placement should be? Maybe on the bottom side opposite of the main extraction fan to keep the thermal flow through the system?

GreenLED said:

I bet you're right, I would have to agree the fan system is fighting itself. Any ideas on where the hole placement should be? Maybe on the bottom side opposite of the main extraction fan to keep the thermal flow through the system?

Click to expand...

Just along the sides. Like this

GreenLED said:

I bet you're right, I would have to agree the fan system is fighting itself. Any ideas on where the hole placement should be? Maybe on the bottom side opposite of the main extraction fan to keep the thermal flow through the system?

Click to expand...

I know from experience playing with PC cases that fans with conflicting air patterns can work against each other. I would place the vents in-between the coolers so the big fan is pushing fresh air through without putting pressure on the fins exhaust... or enough holes that there's not a lot of pressure to begin with.

Rahz said:

I know from experience playing with PC cases that fans with conflicting air patterns can work against each other. I would place the vents in-between the coolers so the big fan is pushing fresh air through without putting pressure on the fins exhaust... or enough holes that there's not a lot of pressure to begin with.

Click to expand...

Truth ^

Even 2 exact fans stacked gets wonky. Offset things go awry.

Rahz said:

I know from experience playing with PC cases that fans with conflicting air patterns can work against each other. I would place the vents in-between the coolers so the big fan is pushing fresh air through without putting pressure on the fins exhaust... or enough holes that there's not a lot of pressure to begin with.

Click to expand...

So you think the big fan should be pulling air IN TO the fixture then?

i would blow air onto the coolers, but exhaust from the top

with as many 1/4" or larger holes on the side as you can drill. ideally the sum of those openings should match or exceed the outlet fan's area

Put a 4-6 inch vent connector on top so you can suck air out of the tent?

All these enclosed designs should have a way to pull air right out of the tent from the light.

Other wise why bother enclosing it at all? Btw I am serious.

If I wanted to sell more lights that is exactly what I would do.

CobKits said:

i would blow air onto the coolers, but exhaust from the top

with as many 1/4" or larger holes on the side as you can drill. ideally the sum of those openings should match or exceed the outlet fan's area

Click to expand...

Ya I would do the same.