BurgerBro
Member
After extensive research, I finally feel ready to make this post. Here is what I want to do:
I want to build a light for my small grow space. To begin with, I will use the same light for everything, and I want to be able to expand later. The light needs to be energy efficient, as electricity is very expensive where I live.
The space is 65 cm wide by 55 cm deep, and I can raise the light to at least 120 cm above the top of the pots.
For those of the Royal persuasion, that is right around 2.1 ft wide, 1.8 ft deep, and with the possibility of raising the light at least about 4 ft above soil level.
I am an experienced DIY person, and have dabbled in electronics before, but the PPF and PPFD, well, I have some vague idea of what it means, but I don't know how much is enough, or too much for that matter.
Here is a parts list that I came up with:
5 CREE CXB3590 36v 3500K CD bin
5 pre-drilled and tapped pin heat sinks of at least 133 mm for passive cooling
1 Meanwell HLG-185H-C1050B
I ran those parts through a java program called "DIY COB LED calculator" that i found, and it gave me a bunch of numbers.
I feel like I understand the ones about the electrics:
I also feel like the heat sink should be OK. I understand that the COBs will perform better, efficiency wise, with better cooling, but I would be running them fairly soft, and judging from other people's builds, these should at least work.
And this is where we get to the limits of my understanding. The "DIY COB LED calculator" program tells me that I would have a total PPF of 460.35 and a PPFD of 1292.22. How close is that to optimal? Is it even good? Given my design goals, should I consider a different build?
Then there is the subject of optics and reflectors. This is also an area where I feel a bit lost. I have, however, narrowed my choices down to these two: A glass lens or a simple white reflector.
I like the glass lens solution because it keeps the COB nicely sealed from the elements. The downside is that it weighs a lot, and will probably cost a bit to ship. The lens also eats some light.
I like the reflector solution because it is light and pretty. The downside is that I will lose some light from the photons bouncing of the reflector and walls, which are covered in MYLAR.
I feel like the choice of COB holder will probably be determined by the choice of optics, and the only thing I have to say about it is that I would like something solder-free.
What would work best in my situation? Reflector? Lens? A combination?
OK, so I guess this post became a bit long. But trust me, dear experts of RIU, when I say I will appreciate your help very much! I certainly do need it.
I want to build a light for my small grow space. To begin with, I will use the same light for everything, and I want to be able to expand later. The light needs to be energy efficient, as electricity is very expensive where I live.
The space is 65 cm wide by 55 cm deep, and I can raise the light to at least 120 cm above the top of the pots.
For those of the Royal persuasion, that is right around 2.1 ft wide, 1.8 ft deep, and with the possibility of raising the light at least about 4 ft above soil level.
I am an experienced DIY person, and have dabbled in electronics before, but the PPF and PPFD, well, I have some vague idea of what it means, but I don't know how much is enough, or too much for that matter.
Here is a parts list that I came up with:
5 CREE CXB3590 36v 3500K CD bin
5 pre-drilled and tapped pin heat sinks of at least 133 mm for passive cooling
1 Meanwell HLG-185H-C1050B
I ran those parts through a java program called "DIY COB LED calculator" that i found, and it gave me a bunch of numbers.
I feel like I understand the ones about the electrics:
- Total forward voltage of 174v, should be within spec of the PSU (90-190v), and it makes sense that the actual forward voltage would be 1 or 2 volts lower than the rated 36v per COB.
- A power consumption in the COBs of 183w also makes sense then, as well as being within the spec of the PSU (199.5w).
- And a total consumption of ~195 w at the wall is also sensible with the loss in the PSU itself (94% efficiency).
I also feel like the heat sink should be OK. I understand that the COBs will perform better, efficiency wise, with better cooling, but I would be running them fairly soft, and judging from other people's builds, these should at least work.
And this is where we get to the limits of my understanding. The "DIY COB LED calculator" program tells me that I would have a total PPF of 460.35 and a PPFD of 1292.22. How close is that to optimal? Is it even good? Given my design goals, should I consider a different build?
Then there is the subject of optics and reflectors. This is also an area where I feel a bit lost. I have, however, narrowed my choices down to these two: A glass lens or a simple white reflector.
I like the glass lens solution because it keeps the COB nicely sealed from the elements. The downside is that it weighs a lot, and will probably cost a bit to ship. The lens also eats some light.
I like the reflector solution because it is light and pretty. The downside is that I will lose some light from the photons bouncing of the reflector and walls, which are covered in MYLAR.
I feel like the choice of COB holder will probably be determined by the choice of optics, and the only thing I have to say about it is that I would like something solder-free.
What would work best in my situation? Reflector? Lens? A combination?
OK, so I guess this post became a bit long. But trust me, dear experts of RIU, when I say I will appreciate your help very much! I certainly do need it.