Best LED for a 2x4x5 tent. Looking to replace a 144x5 Mars Hydro Reflector

tinyplantas

tinyplantas

Active Member
Hi Everyone,

I've been lurking the forums gathering information for the last month or so and would appreciate some advice. I'm looking to replace the Mars Hydro Reflector 144x5 I have in my flower tent. What's the best I can do for around $500? I've looked into building my own but the task is a bit daunting - I've got some idea of what driver / cobs to use but I'm still confused because there are so many options. Right now if I did a DIY the parts list would look something like this;

6 cxb3590 or cxb3070 (36v but otherwise I have no ideas which ones to choose, 3000k vs 3500k, 80 vs 90CRI, etc)
Meanwell HLG-240H-C1400
Alpine 11 plus heatsinks
some sort of AC adapter to power the alpines
Some aluminum framing to piece it together like @bizfactory has done here: http://imgur.com/a/xUyUs

Would appreciate any help and guidance you guys can give at this point. I've been reading and reading but my brain is full and I'm at the point where I need to bounce my ideas off others humans instead of scouring forums and youtube for information.

Cheers!
 
tinyplantas

tinyplantas

Active Member
Ah ok good catch. I'm still having trouble determining how many cobs to use in a 2x4x5 space tbh, seems like 6 would give me ideal coverage, then I can pick driver based on how many cobs I'm using.
 
Rahz

Rahz

Well-Known Member
PicklesRus said:
Check out www.tastyled.com there is a ppfd table on the main page that can help you figure out how much ppfd different cobs provide at different currents
Click to expand...
I think a T4-1750 is a good fit for a 2x4 tent. Similar can be built with your budget, but if you have the inclination to DIY consider doing 8 3590s at .7 amps, or 8 cxb 3070s at 1.05 amps and put some lenses or reflectors on them. At 1 per foot a 60 degree lens wouldn't be unreasonable.
 
zangtumtum

zangtumtum

Well-Known Member
I agree, in your space 6 Cob min, better and ideal in my pov, are 8 Cob.
The situation that I have described to you, example:
two systems COB4 dimmed 75 watt each, 150 watt total, 1200 ppfd for specific area,
but you can dimm to 360 watt in total....
in a restrictions test-space even smaller but similar to your: 1.5x2.5x2.5 (45x75x75cm)
with reduced ventilation, not a realy output airflow,it is more accurate to call "recirculation".
See the distances between lights, are virtually attached,
and even plants can be almost attacked....
In this configuration the temperature remains near Ta, and thanks to this, the plants are 3 inches by COB.
In my opinion, the best led lamp and setting, you will find it in those created only by RIU users projects....
 

Attachments

Last edited:
tinyplantas

tinyplantas

Active Member
Thanks for your responses @zangtumtum @Rahz @PicklesRus @bizfactory

Thanks to your guidance I'm starting to put together a parts list of what I would need:

8 CXB3590 3500k CB bin (8 x $49 = ~$400)
Meanwell HLG-240H-C700 Driver ($76)
Alpine 11 plus fans (8 x $14.50 = $116)

8 leds at 36v (288v) each should match the driver with ~20% headroom (288 / 357 = 80%), am I understanding this correctly?

One thing I'm still wrapping my head around...how do I power the fans, and do I need a heatsink fan for each LED, or could I get by with a passive heatsink and less fans?

Regarding the cobs, I have a few questions:
- Is 3500k ideal for flower?
- Should I consider CD bin, or are they not worth the price increase? What is the best of these options?
- I'm having trouble finding a company that will sell me just 8 cobs, but I'm guessing once I get the parts list finalized I can hit up Jerry from kingbrite.
 
zangtumtum

zangtumtum

Well-Known Member
bizfactory said:
Are you saying you keep your COBs 3" above the plants?!
Click to expand...
yes....exactly, unfortunately the space in height(z) is very little, it's like a stress-test-area.
the COB4 it's very powerful but realy compact with 2 dimmer, it was also studied for these situations and certain powers are allowed to do many interesting things....
 
Last edited:
Rahz

Rahz

Well-Known Member
tinyplantas said:
Thanks for your responses @zangtumtum @Rahz @PicklesRus @bizfactory

Thanks to your guidance I'm starting to put together a parts list of what I would need:

8 CXB3590 3500k CB bin (8 x $49 = ~$400)
Meanwell HLG-240H-C700 Driver ($76)
Alpine 11 plus fans (8 x $14.50 = $116)

8 leds at 36v (288v) each should match the driver with ~20% headroom (288 / 357 = 80%), am I understanding this correctly?

One thing I'm still wrapping my head around...how do I power the fans, and do I need a heatsink fan for each LED, or could I get by with a passive heatsink and less fans?

Regarding the cobs, I have a few questions:
- Is 3500k ideal for flower?
- Should I consider CD bin, or are they not worth the price increase? What is the best of these options?
- I'm having trouble finding a company that will sell me just 8 cobs, but I'm guessing once I get the parts list finalized I can hit up Jerry from kingbrite.
Click to expand...
3590s at .7 amps are 23 watts each. You can fit all 8 of them on a HLG-185H-C700B or split them up on two HLG-120H-C700B if you wanted 2 separate lamps.

You will only have about 35 watts of heat per 4 emitters, so you could go passive with a couple 36" pieces of the 4.23" profile at heatsinkusa.

CD bin at Kingbrite are around $45 each.
 
tinyplantas

tinyplantas

Active Member
Rahz said:
3590s at .7 amps are 23 watts each. You can fit all 8 of them on a HLG-185H-C700B or split them up on two HLG-120H-C700B if you wanted 2 separate lamps.

You will only have about 35 watts of heat per 4 emitters, so you could go passive with a couple 36" pieces of the 4.23" profile at heatsinkusa.

CD bin at Kingbrite are around $45 each.
Click to expand...
Thanks, this is very helpful.

By my math:

36v x .7 = 25.2 W per led x 8 = 201.6 W total for all 8 leds

The HLG-185H-C700 is rated at 200.2 W, so slightly less than the driver wattage, is that ideal, or would it be better to have a driver with more wattage like the HLG-240H-C700?

Also it is my understanding that the C700A has a built in dimmer, but the C700B I would need to install a potentiometer for dimming, is that correct?
 
Rahz

Rahz

Well-Known Member
At .7 amps you can expect the 3590 to use about 33 volts, so 8 will fit nicely on the 200w driver.

You're correct about the A and B version. If you plan on adjusting much it would be worthwhile to add the external dimmer to a B version, either with a potentiometer or a resistor on a switch.
 
tinyplantas

tinyplantas

Active Member
Rahz said:
At .7 amps you can expect the 3590 to use about 33 volts, so 8 will fit nicely on the 200w driver.

You're correct about the A and B version. If you plan on adjusting much it would be worthwhile to add the external dimmer to a B version, either with a potentiometer or a resistor on a switch.
Click to expand...
Ok good point, thanks for clarifying. I am almost ready to place an order, here is my parts list revised:


CXB3590 3500k CB Bin $49 each - $400 for 8

passive heatsink: 2 x 36” 4.23 = $102

HLG-185H-C700b: $65

Wires, chiplok holders, power cord, potentiometer, multimeter, kw meter, etc.

Will I need some sort of PC fan to attach to the heatsink? I was really expecting to have to get some alpine arctic 11 plus style active heatsinks but I suppose they won't be necessary - would that make sense or is it overkill for this setup? Cost for 8 of them is comparable to 2 36" 4.23 passive heatsink bars.
 
Rahz

Rahz

Well-Known Member
With that much aluminum you don't need no stinking fans. You're buying $100 dollars of metal for a 200 watt lamp. It will be a great lamp. Hit your local hardware store and buy some aluminum angle and use it to bond the two sinks together and create an anchor point for the driver. While you're purchasing the driver get a handful of wago 413s and a 415 for AC and DC distribution, a ring connector that fits the AC wire gauge you're using for a redundant ground, a 10k ohm resistor to run in series with the pot, a piece of shrink tubing, a bag of 7 inch zip ties. Always have some zip ties laying around. :)

Having said all that... adding a fan or couple fans to the lamp would just make it more bad ass. You might only get 1-2% more light from it, but you're looking at 15 watts for two fans? It could be worth it. The lamp you're building isn't maxing things out, it's seriously improving the yield of your current setup while getting extreme performance (64% efficient emitters) from 200 watts in a 2x4. It will be like it's not even there. Benefits of DIY.
 
Airwalker16

Airwalker16

Well-Known Member
tinyplantas said:
Ok good point, thanks for clarifying. I am almost ready to place an order, here is my parts list revised:


CXB3590 3500k CB Bin $49 each - $400 for 8

passive heatsink: 2 x 36” 4.23 = $102

HLG-185H-C700b: $65

Wires, chiplok holders, power cord, potentiometer, multimeter, kw meter, etc.

Will I need some sort of PC fan to attach to the heatsink? I was really expecting to have to get some alpine arctic 11 plus style active heatsinks but I suppose they won't be necessary - would that make sense or is it overkill for this setup? Cost for 8 of them is comparable to 2 36" 4.23 passive heatsink bars.
Click to expand...
This is what I was going to do but decided to do 3 cobs on 3 heatsinks of 28". And use a fan too. But you realize you'll only be pulling 23w per cob. That's fine but I'll be using s 120-1400 on each of mine for 52-56 w/ec.
 
Airwalker16

Airwalker16

Well-Known Member
Rahz said:
With that much aluminum you don't need no stinking fans. You're buying $100 dollars of metal for a 200 watt lamp. It will be a great lamp. Hit your local hardware store and buy some aluminum angle and use it to bond the two sinks together and create an anchor point for the driver. While you're purchasing the driver get a handful of wago 413s and a 415 for AC and DC distribution, a ring connector that fits the AC wire gauge you're using for a redundant ground, a 10k ohm resistor to run in series with the pot, a piece of shrink tubing, a bag of 7 inch zip ties. Always have some zip ties laying around. :)

Having said all that... adding a fan or couple fans to the lamp would just make it more bad ass. You might only get 1-2% more light from it, but you're looking at 15 watts for two fans? It could be worth it. The lamp you're building isn't maxing things out, it's seriously improving the yield of your current setup while getting extreme performance (64% efficient emitters) from 200 watts in a 2x4. It will be like it's not even there. Benefits of DIY.
Click to expand...
Rahz, on the 240-2100 or 120-1400 "B" style meanwells, you mention 10k pots. Mine will be 3 cobs per driver but don't I use a 100k one?

Also, if I'm running at 52-76 watts on either of those drivers mentioned above, will a 28" x 5.886" heatsink be enough for passive or should I add the fan and the U shaped sheet metal I told you about earlier. There will be a cob right in the middle so I'd probably have to do 2 fans with this style in the 2 open spots on a 3 cob spread right?
 
bizfactory

bizfactory

Well-Known Member
Airwalker16 said:
Rahz, on the 240-2100 or 120-1400 "B" style meanwells, you mention 10k pots. Mine will be 3 cobs per driver but don't I use a 100k one?
Click to expand...
The 10k fixed resistor he's talking about goes inline with the 100k potentiometer to limit the dimming from 10%-100% since you can damage the driver going below 10% I think.
 
Airwalker16

Airwalker16

Well-Known Member
You must log in or register to reply here.
Top