Calculating ppfd output of vero

G

George2324

Well-Known Member
Looks like I've decided on going for the vero gen 7 29 C version 3000k 90 Cri

anyone here able to help me calculate the ppfd output of these cobs when run at 1.4a each 69V One per square foot?


Cheers
 
A lot.

I have mine running between 10 and 46w (150-700ma) each and they are smashing out photons like nothing else. With 6 to an aluminum sheet measuring 8x16" (centers are 4.5" between cobs) and them being 120 degree spread, they put out around 1500ppfd up to 30" in the center on full power according to my par meter. Each of these units cover a 2.5x3' area with excellent side reflection going to the lower rears of the plant.

Yes I can probably do better with spacing between the cobs but I have several of these 6 cob units so it results in higher density of cobs over the full area.

One thing I will suggest is to get as many cobs as possible. Specialty heat sinks aren't needed and in some opinions' a waste of money if you plan on running the chips low. Veros are very good for heat transfer and have a high tolerance for heat. Drivers are another area to save money on but that is a personal preference. You can go with 1 single driver for multiple cobs or use 1 driver per cob. I just happen to use 1 driver per cob.

Also the SE version has poke in connectors that work great using 18g solid wire. Highly recommended for simplicity and ease of assembly. Plus you can quickly change out cobs if you want to try something new, for example a 4:2 mixture of 80/90 cri against 6 of either 80 or 90 cri.

More light it always the best route. It isn't a beauty contest.
 
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So you have 4 cobs per square foot to get the 1500 ppfd?

I'm wanting 1500 ppfd across my entire canopy

You have around 200w per sq ft heck of a lot more than I plan on having
I might need more cobs then... I was planning on 80 cobs at 1 per sq ft
 
The fixture is 1ft2 (8x16") but covers a 2.5x3' growing area. Think tough box with a shoe box hanging over it. It works out to being about 1.3 something square feet per cob and the highest I would run them is 264w which works out to 33w/ft2 over an 8ft2 area.
 
But if you get 1500 directly under the fixture that 1500ppfd is from 4 cobs per sq ft.

I assume the outside of the canopy would be getting barely 500 ppfd?
 
No, that's for the effective canopy area getting 1500ppfd. I don't use reflectors or optics on the cobs so they are 120 degree angle and the spread works for that space. Outside that area the light either gets reflected off the walls or into the adjacent grow area hitting the lower regions of plants growing beside it.

Rather than spreading out the cobs, I have a number of units that have a cluster of 6 together. This helps me with placement and airflow. All those bulky frames and heat sinks just get in the way. I could do the same thing running 2 8' bars with 12 cobs each but I wouldn't have the flexibility to independently adjust each of the growing areas.

Also, I have been able to subject leaves to 3000+ppfd and it looks like the plants can handle it so long as the temperature is kept low. Doesn't mean they grow more but they do seem happy.
 
Raging Stalk said:
A lot.

I have mine running between 10 and 46w (150-700ma) each and they are smashing out photons like nothing else. With 6 to an aluminum sheet measuring 8x16" (centers are 4.5" between cobs) and them being 120 degree spread, they put out around 1500ppfd up to 30" in the center on full power according to my par meter. Each of these units cover a 2.5x3' area with excellent side reflection going to the lower rears of the plant.

Yes I can probably do better with spacing between the cobs but I have several of these 6 cob units so it results in higher density of cobs over the full area.

One thing I will suggest is to get as many cobs as possible. Specialty heat sinks aren't needed and in some opinions' a waste of money if you plan on running the chips low. Veros are very good for heat transfer and have a high tolerance for heat. Drivers are another area to save money on but that is a personal preference. You can go with 1 single driver for multiple cobs or use 1 driver per cob. I just happen to use 1 driver per cob.

Also the SE version has poke in connectors that work great using 18g solid wire. Highly recommended for simplicity and ease of assembly. Plus you can quickly change out cobs if you want to try something new, for example a 4:2 mixture of 80/90 cri against 6 of either 80 or 90 cri.

More light it always the best route. It isn't a beauty contest.
Click to expand...

Got any pics?
 
Apparently not. Heat above 30 degrees causes bleaching though. I am actually doing this test because I now think that there is no such thing as light bleaching. Every fan leaf on the plant is pointing up like it is praying. Same can be said of the 2k ppfd, 1500ppfd and 1k ppd plants as well though.

I do have really good air flow to do this. Canopy sits 2-3 degrees above ambient when the lights are on. Even me going into the area raises the temperature by a degree and takes a good 10 mins to go back down.
 
I've had completely white albino nugs from a commercial LED fixture when canopy grew too close to the light.

Canopy temps were definitely below 30 probably more like 25.

I am using CO2 Now tho hence wanting 1500 ppfd
 
Surely though If you turn on just one of your fixtures and measure the ppfd directly under the light... the ppfd you get would be from 4 per sq ft right?
 
Was still more likely due to heat. The plant turns excess light energy it absorbs into heat so even if you had a canopy reading of 25, if you didn't have adequate air flow then it would still suffer heat stress.

Anyhow that is what I have found so far. Also, with the amount of air circulation, all leaves on all the plants move at least once per sweep cycle. It probably allows more light to get down into the inner leaves giving the upper ones a bit of a rest.

@klx, hopefully sometime if I decide to get one of those phones with a camera built in.
 
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George2324 said:
Surely though If you turn on just one of your fixtures and measure the ppfd directly under the light... the ppfd you get would be from 4 per sq ft right?
Click to expand...


Actually more like all 6 cobs. I think I see what you mean now, but we are talking two different things.

What I suggest you do is read the spatial and polar radiation pattern in the bridgelux data sheets. Each cob will overlap with one another increasing the light power over that of just one cob. That's how I can get a min 1500ppfd across a 2.5x3' canopy. Sure there is lots of extra light outside of that but it is being reflected or used elsewhere.

120 degree is a pretty wide spread.
 
Unfortunately, I only have a cheap lux meter and only had one measurement taken against a good PAR meter. The cheap thing on the left is mine, but I could tell you in lux if it isn't max out.200klux to PPFD.jpg
 
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