New LEDs for my grow room

[DelawareJim]

A member of my local aquatic plant club ran across a new LED vendor called "Build My LED". Build My LED Custom LED Lights for DIY Horticulture Aquarium Hobby Lighting

After visiting the site, I was intrigued because they had both horticultural and aquarium systems and you could design you own. Looking at the design you own option, I discovered they list their LED emitters by spectral wavelength, plus a couple of "white", and by beam angle rather than by perceived color temperature as everyone else does. You can also generate a report to show expected spectral analysis, PAR, lumens, efficiency, power consumption, etc. he also has a link to a study NASA conducted back in 2004 on green-enhanced lighting which is a really interesting read.

A quick email with some questions and the owner calls me back. It turns out, he has a background in horticulture, and worked for a top horticultural lighting company designing lighting systems for research facilities of some of the biggest names in the horticultural industry. He decided to leave all that and start his own company. We discussed some of the latest research in light and photosynthesis, and then about some of my plans for an LED system for a seed starting set up and for growing emersed aquatic plants in empty aquariums (for humidity), getting dimensions, planned fixture height above the plants, etc. He then sent me some 3-D PAR models to show how some recommended lights would light the setup which I posted in the club forum.

Here's the complete thread:
GWAPA • View topic - Buildmyled.com

All that said, the guy knows what he's about and for anyone looking into LED's, in my opinion, this is THE place to go.

Cheers.
Jim

[DavidCampen]

That is a nice looking product. Still it is $5 per watt compared to $1 per watt for an equivalent water resistant fluorescent fixture fitted with specialty grow bulbs. The price still needs to come down by a factor of 2 or so to be generally competitive with fluorescent plant growth lighting.

I would consider buying these LED fixtures instead of building my own for applications where I want a narrow beam angle. I would have to verify though that he is using the same definition of beam angle as I expect which is the total interior angle (called FWHM, Full Width Half Maximum) and not 1/2 the interior angle. Also, his most narrow beam angle is 30 degrees while for my applications I use optics with a beam angle of 14 or 22 degrees.

One minor nit, he lists the output of the fixtures in micromoles, which is nice, except that I presume he means micromoles per second.

Edit:
A more major criticism, just like every other vendor of one of the new types of lighting, he is making ridiculous claims about the type of lighting he sells being so much more efficient than other types of lighting.

Here he claims that 260 watts (input power) will replace 660 watts of HPS. I say that that is bull.
4'x4' Horticulture Lighting Design | Build My LED - Lighting Discussion Forum

[DelawareJim]

Okay...Maybe you can solve my conundrum then.

My current flourescent fixtures I use in my grow room are dying of old age. They're lighting various orchids, house plants, seedlings and tissue cultures.

Specifically, I have a grow chamber where I need a completely new lighting system that will not raise temps more than 5 degrees above ambient temp in a sealed box approximately 48" x 24" x 60" high. I would prefer lighting in 450-500 nm and 630-700 nm wavelengths, and could produce as much or more useable light whilst using less electricity as we recently de-regulated and my electricity rates are almost doubling.

What do you recommend?

Thanks.
Cheers.
Jim

[littlefrog]

I haven't made much noise about it yet, but I'm selling a 4' LED 'tube' that fits right into a t8 or t12 fluorescent fixture. You might see others selling them soon. The nice thing is that they aren't that expensive (~$30 per 'tube'), and they don't use the ballast that comes in the fixture. So, for old fixtures that are dying, you open them up, do a little simple wiring (pulling out the old ballast) and put everything back together, throw the LED tubes in.

Plus side, you get to reuse your fixtures, and they are drawing a fair amount less power (on my meter, the white tubes draw 15W). They are also cool to the touch. And actually compared to most of the other LED products out there, the price per unit area (as long as you have rectangular areas) is pretty darn good.

Now everything has a downside... First, I haven't tested these for a long time yet, I don't know how durable they are but they seem pretty good. Second, the only 'growlight' style tubes I can get (red and blue) are not particularly powerful. The white ones are bright as heck (easily the same as a T8 bulb).

Also have 2' tubes...

Just a thought.

Rob

Originally Posted by DelawareJim

Okay...Maybe you can solve my conundrum then.

My current flourescent fixtures I use in my grow room are dying of old age. They're lighting various orchids, house plants, seedlings and tissue cultures.

Specifically, I have a grow chamber where I need a completely new lighting system that will not raise temps more than 5 degrees above ambient temp in a sealed box approximately 48" x 24" x 60" high. I would prefer lighting in 450-500 nm and 630-700 nm wavelengths, and could produce as much or more useable light whilst using less electricity as we recently de-regulated and my electricity rates are almost doubling.

What do you recommend?

Thanks.
Cheers.
Jim

---------- Post added at 10:35 AM ---------- Previous post was at 10:32 AM ----------

I concur that this seems a bit too good to be true... One thing that you see coming out of China (and I buy out of china a lot) are lights listed at X watts (where X is very high), but when you actually put them on a meter they draw 1/2X or less. Some of this is on purpose (you don't want to run 3W LEDs at the full 3W, I guess, and different colors run at different voltages). Some of this is hype...

Originally Posted by DavidCampen

A 600 watt LED fixture with 200 3watt LEDs for $400! I find that hard to believe. 2 watt to 3 watt LEDs from a reputable manufacturer, LEDs only- no housing or power supplies, will cost you $1.50 each in lots of 1000.
High Power LEDs - White | Mouser

[DavidCampen]

Originally Posted by littlefrog

. Second, the only 'growlight' style tubes I can get (red and blue) are not particularly powerful. The white ones are bright as heck (easily the same as a T8 bulb).

This is probably an artifact of the sensitivity of human eyes to different colors of light. Human visual sensitivity peaks at a wavelength of 555 nm (green). The eye is 16 times more sensitive to 555 nm light than it is to 660 nm light (deep red) and 250 more sensitive to 550 nm compared to 420 nm (blue).

Most inexpensive light meters are also made for measuring illumination for human use and have a green filter to make them a closer match to the sensitivity of the human eye.

Luminous Efficacy

[littlefrog]

Actually in this case I meant wattage, not visual intensity. The red/blue 'tube' leds are sold as 10W (sometimes 15W), but I've never had one draw much more than 5W. I don't have the equipment to validate my assumptions, but I usually assume given the same wavelengths (ish) that the more wattage the fixture draws the more light I'm getting. I'd really love to get the tubes as true 10W, or using a different chip, but I'm limited to what I can purchase.

That said, I still use them. I'm mixing them 1:1 in fixtures. White and color. It does seem to be a good solution, white is nice for viewing the plants, and the color is there to add to the growing spectrum. It is just one of many setups I'm trying...

[DavidCampen]

If you can afford them then these LED modules will work. If you use 460/660 nm LEDs (only 20% or 25% at 460 nm) then you may be able to use 2/3 the wattage of T8 or T5 fluorescent; so 80 watts of 460/660 nm LED replaces 120 watt of T8 or T5.

Do you have the existing fluorescent fixtures outside of the case? I would guess that you do. The LED fixtures at 2/3 the input wattage will produce 2/3 the heat. The narrower beam spread LED fixtures would likely be advantageous.

[ronaldhanko]

Very interesting, Jim. These are looking more and more like the choice of the future.

[escualida]

That's pretty expensive, I just bought a light from this seller on eBay, they manufacture LED grow lights in China and ship them directly from there. They are really, really good quality.

LED Grow Light, Bulk Order items in ledgrowlightmanufacturer store on eBay!

It took like 4 days for the light to get here and is SUPER powerful, way more than I need but I'm happy with it and the plants are blushing and doing well. They have built in fans and the temp doesn't go up very much, obviously it would depend on the strength of light you get.

[DavidCampen]

Originally Posted by escualida

That's pretty expensive, I just bought a light from this seller on eBay, they manufacture LED grow lights in China and ship them directly from there. They are really, really good quality.

LED Grow Light, Bulk Order items in ledgrowlightmanufacturer store on eBay!

It took like 4 days for the light to get here and is SUPER powerful, way more than I need but I'm happy with it and the plants are blushing and doing well. They have built in fans and the temp doesn't go up very much, obviously it would depend on the strength of light you get.

A 600 watt LED fixture with 200 3watt LEDs for $400! I find that hard to believe. 2 watt to 3 watt LEDs from a reputable manufacturer, LEDs only- no housing or power supplies, will cost you $1.50 each in lots of 1000.
High Power LEDs - White | Mouser