Building Costum Diy Led Setup With 4sq^2 Space (secret Jardin Dr60) In Mind

[pumpkinhead]

Esteemed room-foggers,

The title neatly sums up my inquiry. I am planning my first grow room, I would be happy to produce between 20-40 grams of green (vanilla kush / tangerine dream) per month. I have not yet made any purchases; everything is in the planning stage. I will probably have a separate room to maintain two bonzai mothers.

Due to space constraints, I am looking at the Secret Jardin DR60. I am quite determined to make my own LED setup using Cree CXA cobs, I know HPS is cheaper and all that, but I am really keen getting my hands dirty and learning some electrical basics, so building my own lights is a big enjoyment factor here.

My main question for you fine smoke-dispensers is; how much Cree CXA light should I aim to squeeze into this small tent? Is 5x CXA3070 overkill? I'm thinking I need about 5 units to get a good balance of light temperatures; what wattage should I aim for within this particular tent?

Lets talk temperature. The tent would be in an 18C climate (standard indoor temp, right?), it might get as high as 23-25C in the summer. Ideally, I would like the cobs and their drivers to create the cozy optimal kush temps on their own without additional heating. Whether or not I place the LED drivers inside, or outside the tent will obviously have a big impact on this, so I'm thinking (as I'm writing) that portable drivers that can be removed from the tent during the summer would be pretty dandy.

In terms of cooling, I could go active or passive. I would have 170cm of height to work with in this particular tent. Active cooling grants me more light, at the cost of height and wattage for fans. Passive cooling does the opposite. The real question here is if, given the small size of my tent, more light is worth the cost of taller heatsinks and fan power?

TL;DR: I has 4sqft tent, want build DIY LED - how much light not silly and maintain nice tempz?

Thanks in advance <3

 

[sixstring]

Good questions for @REALSTYLES
Check out his threads.and welcome to the site

 

[pumpkinhead]

Good questions for @REALSTYLES
Check out his threads.and welcome to the site

Thanks for the welcome :)

I've done some more research, and learned that I should aim for 50W per sqft, so 200W in total. I'm therefore thinking Cree CXA2520 (46W max): 1x 5000k + 2x 2700k + 2x 3000k. This totals 230W at max capacity. I'm guessing I want a bit of safety margin, so they would ideally be paired with drivers that feed them less than max capacity, meaning my total would be closer to 200W.

Am I correct when assuming more juice would be overkill within the Secret Jardin DR60 rev2.5 (60x60x170 cm)? I have noted that the lumens per dollar value is better with the more powerful models (CXA 2530 and up), but a similar composition of 5k vs 2.7 & 3k would land me at well over 360W.

Also, feel free to comment on the 5k to 2.7 - 3k ratio-- I want this chamber to handle clones from my bonzai mothers, infancy to harvest, so maybe I should be looking at a two-mode functionality for my lamp?

 

[jofo]

Fwiw, I have five CXA/B's in a small grow cab (24" x 36" footprint). 100mm fans on arctic heat sinks for each COB. They run cool, and with moderate airflow keep the temp inside the cabinet within 8degF of ambient. I have three CXA's and two CXB's for a total of 250W nominal, all running at 1.5A, all 3K's. I take my clones directly from T5's to the 3K's and harden them off at reduced power for a week or so. If I understand the math correctly, I'm getting about 900 micromoles per sq m, in this case about 40W/m2 nominally. I have them five in a line; the coverage over the 2 x 3 area is very even and I keep the light about 12" from the tops with no heat issues (could get 4-5 inches closer I think). The drivers are mounted externally.