growing inside--efficiently

[JohnnyBlaze]

Greetings from Geneva Switzerland!

the days are getting shorter, and my not-so-temperate CPs (the ones that aren't supposed to go dormant) are starting look a bit wimpy, so I was thinking of setting up an indoor terrarium with artificial lighting.

what would be the most energy efficient lighting setup I could use to keep them vigorous over the winter season?

Thanks for your suggestions :)

[mobile]

The most efficient, readily available lighting, would be LED as the correct wavelengths can be selected to match those required for photosynthesis, thus there is very little waste energy. However, plants under this type of lighting do not make a very nice display as it is very monocromatic. Also, there are a lot of cheap LED panels available that simply are not powerful enough for good plant growth. Personally, I would choose fluorescent lighting. There are lots of discussions on the forum as to which tubes are best but I use normal warm and cool colour tubes. Fluorescent tubes such as grolux, which are designed for plant growth, will produce light more targetted at the photosynthesis bands, so would be more efficient.

Edited October 2, 2009 by mobile

[faunista]

If you are searching for efficient fluorescent lights, there are some interesting HE tubes (high efficiency). For example some T5 by Philips produce 1750/1900 lumens with 21 watt of consumption (tube lenght 84,5 cm so fits well in a 90 cm/1 m terrarium): so, up to 90,5 lumen/watt and I think this is quite efficient.

[-=Joel=-]

If you have the cash these are what you need

They also do a marine version of this tile which may or may not be better suited.

http://www.tmc-ltd.co.uk/planted-tank/grobeam-1000.asp

The GroBeam 1000 uses 6500K natural daylight Compact PowerLEDs emitting over 800 lumens making it especially suitable for planted aquariums

[mobile]

If you have the cash these are what you need

They also do a marine version of this tile which may or may not be better suited.

http://www.tmc-ltd.co.uk/planted-tank/grobeam-1000.asp

And only ≈£200... bargain lol

[jesse]

what would be the most energy efficient lighting setup I could use to keep them vigorous over the winter season?

Thanks for your suggestions :)

I would recommend:

For small setups up to 30x60cm terrarium ==> white high-power LED lighting

For big setups (grow rooms) ==> high-pressure sodium (HPS) lamps

For anything between in size ==> T5 fluorescent lamps

Until now LED lighting must be made do-it-yourself to be powerful, efficient and affordable at the same time. If you are interested in LED, then you better don't purchase china-made "LED grow panels" built from two-coloured low-power LED at eBay, those are pure crap, but you should be prepared to grab a sow, two-component adhesive and soldering iron to assemble your own LED grow lights.

[agreendream]

I have a 9ft long 1ft deep unit I NEED to light, I have just contacted the sales team of Cree after reading the Joel's bit.

As Jesse says the China Ebay grow panels are BAD. If your going to take advantage of the new range of LEDs you will have to make the boards up by your self.

Which is what I plan on doing.... Not some thing I think I will be great at but I will learn!

Will post pics of the damage when it begins.

:)

[mobile]

Does anyone have a link to the spectral distribution chart of CREE LEDs? I would be interested in seeing how much of the light is in the PAR region.

[jesse]

Does anyone have a link to the spectral distribution chart of CREE LEDs? I would be interested in seeing how much of the light is in the PAR region.

A diagram of the "Relative Spectral Power Distribution" is in the datasheet:

http://www.cree.com/products/pdf/XLamp7090XR-E.pdf

Cree is offering different white high-power LEDs, I'm using the white ones in the 5000K to 10000K range (blue curve in the diagram).

I have a 9ft long 1ft deep unit I NEED to light

Looks like you are in the perfect range to use T5 fluorescent lamps.

To achieve best efficiency you should use good (=deep) reflectors, so that the maximum light is bundled downwards.

Edited October 3, 2009 by jesse

[agreendream]

So you have made up your own Cree LED boards all ready Jesse???

Any chance you could show some pics + description of the build.

:)

[jesse]

So you have made up your own Cree LED boards all ready Jesse???

Yes, I have!

About one year ago I assembled a small propagator box like this with home-made LED lighting:

http://www.amazon.de/Zimmergew%C3%A4chshau.../dp/B0027YWP5K/

These propagators (38x24cm square, 18 cm total height) are sold in (almost) every gardencenter in Germany for about 5 EUR. As LEDs are costly, I wanted to start small. It works good for germinating seeds, leaf-propagation of Drosera, growing seedlings and small plants that need some extra lighting in winter.

I used 8 LEDs of specification "Cree XR-E, Q2 binning, WC color bin" and a 350 mA constant current power supply with 230 V input. Total power consumption is 10 Watt.

Any chance you could show some pics + description of the build.

That should be possible, with some efforts. Perhaps I should set up a website or small blog, take some pictures and write additional text, so that the result is some kind of detailed construction manual?

[-=Joel=-]

From what I have read & seen going DIY wont actually save you loads of cash which is surprising. The only really benefit is getting the LED colour of your choice which has already been done for the freshwater plants. May not suit our eyes (may be a little yellow ?) but they should work, the marine set has been getting some great reviews.

You will need the LEDS, board, wire, heatsink, casings etc etc etc

Might be worth finding a local shop & see how much discount you can get. May save you a whole load of time & trouble, well, unless you really know what you are doing.

[Tha_Reaper]

time to revive this half dead thread... I ordered the supplies for building my LED panel a week ago, and now i stumble on this thread.

I;m building around the same setup like Jesse it seems.

Also the Cree Q2 Cold White LED lights, but i run them at 700 mA, and not at 350. Also 8 of them for a similar space.

Probably the big difference will be that will build my own box, and that the box will be out of full aluminium, or wood which i will coat with reflective foil all around. The lid will be aluminium.

@Joel: it isnt much trouble at all of you can find the right drivers for the leds. with the right drivers, you just hook the driver to 220v, and the led to the driver, and you are done. minimal soldering for dummies.

The heatsinks are no problem unless you want to lock them up in a closed space. Just glue them to a piece of aluminium with thermal grease, and the warmth will spread through the aluminium well enough to keep the leds and the box cool. (i already have 1 LED and tested with that one before i placed the bigger order of another 7 LEDs). Optics are not nescessary, and will only prevent the LED from losing his heat.

[manders]

White LED's are not more efficient than a good high efficiency fluorescent, and may actually be worse, also most of the figures quoted are only attainable in a laboratory under ideal conditions.

[jesse]

Also the Cree Q2 Cold White LED lights, but i run them at 700 mA, and not at 350.

...

The heatsinks are no problem unless you want to lock them up in a closed space. Just glue them to a piece of aluminium with thermal grease, and the warmth will spread through the aluminium well enough to keep the leds and the box cool.

Don't underestimate the area of aluminium sheet material you need for 700 mA operation!

The light efficiency and lifespan of LEDs is much better when running cooler, so better cooling means better efficiency (Lumen per Watt) and longer lasting LEDs.

White LED's are not more efficient than a good high efficiency fluorescent, and may actually be worse, also most of the figures quoted are only attainable in a laboratory under ideal conditions to operate LEDs.

If you provide the specified operation conditions, you get the specified amount of light from a LED. The most important operating conditions are a low operating temperature (provided by heat sink) and appropriate current (provided by a constant current unit). You need no laboratory conditions.

The big advantage using LEDs in small setups is: LEDs send out all their total light in a beam with about 110 degree opening angle (white CREE LEDs) in one direction only. Fluorescent bulbs shine 360 degree around them. So with the same nominal efficiency of 100 lumen/watt in total you will get more luminous intensity (lumen/area) in one direction with LEDs compared with fluorescents. You will need the very best reflectors for your fluorescent bulbs available on the market to achieve the same luminous intensity (lumen/area) for your plants as you can achieve with good Cree LEDs using just 10mm of headroom for the lighting construction (Cree emitter on star platine glued to an 4mm aluminium plate as a heatsink).

[Tha_Reaper]

Don't underestimate the area of aluminium sheet material you need for 700 mA operation!

The light efficiency and lifespan of LEDs is much better when running cooler, so better cooling means better efficiency (Lumen per Watt) and longer lasting LEDs.

I try to keep them as cool as possible, but i've run my test-led at 700 mA for 20 minutes only on the star heatsink that came with it. After those 20 minutes, the star heatsink was hot, but far from impossible to touch. I dont know if you tried it before, but its temperature was much the same as the base of a 20-23 watt CFL bulb that ran for an hour.

When i glued it to a 5x5 cm base of aluminium, the aluminium did get lukewarm, the star was ok to touch (warm, but not hot). I did not notice any difference in light output though, but that might be too difficult to see with the human eye. I know that the first time i tried the led, i was looking at the contact points too much to press the wires of the driver on them, that i got totally blinded by the light. I had trouble reading subtitles on TV even 30 minutes after that happened because those funky dots were all over my sight. 700 mA is a lot, but these LEDs are designed for 1 A and the heat that is generated at that current... also dont forget that. running it at 350 mA is a waste of money and potential IMO.

I hope my plants grow well under LED lights, as i'm well ware that not every plant will react in the same way to the same light.

It's more like an (expensive) experiment

[jesse]

I try to keep them as cool as possible, but i've run my test-led at 700 mA for 20 minutes only on the star heatsink that came with it.

I cannot recommend using more than 350 mA when the star platine is the sole heatsink, even if trying out something for a short time. The star platine is more to be seen as an emergency heatsink and for permanent use this should always be glued to some bigger heatsink like an aluminium plate.

After those 20 minutes, the star heatsink was hot, but far from impossible to touch. I dont know if you tried it before, but its temperature was much the same as the base of a 20-23 watt CFL bulb that ran for an hour.

Very strange. Here a star platine goes up in temperature to an estimated 75°C even using 350 mA only within a minute and I cannot touch it for more than a second as it is so hot.

When i glued it to a 5x5 cm base of aluminium, the aluminium did get lukewarm, the star was ok to touch (warm, but not hot). I did not notice any difference in light output though, but that might be too difficult to see with the human eye.

The loss of efficiency is not really visible. If you assume 350 mA = 100% lumen and you double the current to 700 mA (+100%), then you will have 180% (+80%) of the lumen at 350 mA.

I know that the first time i tried the led, i was looking at the contact points too much to press the wires of the driver on them, that i got totally blinded by the light. I had trouble reading subtitles on TV even 30 minutes after that happened because those funky dots were all over my sight.

Don't try that at home! Your retina gets burnt and after looking directly into high-power LEDs your retina can surely have more than one blind spot. Very dangeous! Never look directly into a working high-power LED!

I hope my plants grow well under LED lights, as i'm well ware that not every plant will react in the same way to the same light.

It's more like an (expensive) experiment

I am experimenting for a year now with a small propagator box equipped with LEDs.

Reactions of the plants are different. So far I achieved excellent results with

- leaf propagation using Drosera leaf cuttings (temperate and tropical species)

- growing Dionaea seedlings over winter

- growing Sarracenia seedlings over winter

- growing Utricularia sandersonii, livida, blanchetii, calycifida, crysantha

As my LED propagator box is only small, I can keep only very small plants in it.

[benenthes]

concerning flourescent light tubes;

I am using T8 and T5, and I've read about it a little-

The optimum light output is at 35°C or so with t8 light tubes, so over room temp.

T5 has its optimum light output at 25°C or so, so room temp., that means almost no energy is wasted in thermic energie.

my opinon -- T5 --

Ben

[Peabody]

I have made an Ebay from China order for two white Cree LEDs each mounted on a generous finned heatsink and each are complete with a driver for 10 - 16 volt operation and I think they will consume about 4 Watts each. They have got lenses for a 10 beam. I have not received them yet - they are for my brother for Christmas for headlights for his bike. The lenses can be easily removed and that will give a 120 degree spread of light. Each LED/heatsink/driver combination was about £10. The Cree LED is rated at 230 Lumen per Watt. You can find the ones I ordered on Ebay by searching for something like "Cree Q5 Ultrabright LED DIY". The only problem with running several high powered is organising a power supply capable of providing several amps.

[manders]

The Cree LED is rated at 230 Lumen per Watt.

I thought the best available were >~107 Lumens / Watt and many of the CREE are actually between 60-90 Lumens per watt, is this a new type?

[Peabody]

I thought the best available were >~107 Lumens / Watt and many of the CREE are actually between 60-90 Lumens per watt, is this a new type?

The Luxeon III is about 90 Lumens I think but the Cree Q5 is currently the brightest by a long way. Some of the mountain bike fraternity are into bright lights for night riding and they are choosing the Cree LEDs to make their own headlights.

[Tha_Reaper]

not in a long way... the Q5 is rated at 228 Lumen at 1 Ampere, that is 3 watt, so it actually gives you 76 lumen/watt

You have been misinformed if someone told you otherwise. if you run it at 700 mA, then you get 181 Lumen.

The brightest (costumer) LED at the moment is the Seoul Semi Conductors P7 E bin series, rated at 900-1100 lumen at 2800 mA. But this is an 10 watt led emitter

Edited December 6, 2009 by Tha_Reaper

[jesse]

The Cree LED is rated at 230 Lumen per Watt.

I don't think so.

The rating should be "230 lumen per LED" max. output rating at something like 3 Watt power consumption.

Please read the datasheet carefully!

LED emitters with the "Q5" ordering code are about 107 lumen per watt, and if you want to achieve this output efficiency, you must power the emitter with 350 mA only (instead of 1000 mA max. rating).

Until now there is no LED on the market with a 230 lumen per watt rating.

The only problem with running several high powered is organising a power supply capable of providing several amps.

I don't think so.

If you want to power several high-power LEDs with constant current, please do not use flashlight drivers! Flashlight LED drivers are for one LED only. Instead you can use a constant current driver which has an input voltage of your local mains voltage (230V AC in Germany) and an output voltage that fits for a series connection of LEDs. For a series connection just add the forward voltages of the LEDs. I.e. for CREE XR-E you can take 3.3 V as the forward voltage. If you want to power 10 LEDs in a series connection, which is a total forward voltage of 10*3.3 = 33V, you will need one (!) constant current driver of these

- Input 230V AC, Output 10-36 V DC, constant current 350 mA or 700 mA or as needed

- Input 230V AC, Output 12-54 V DC, constant current 350 mA or 700 mA or as needed

- Input 230V AC, Output 30-72 V DC, constant current 350 mA or 700 mA or as needed

They are all in the range to power 33 volt forward voltage of LEDs in a series connection.

Perhaps your China buyers source has only flashlight LED drivers with low voltage or batteries input.

But there should be enough local dealers in your country to offer constant current LED drivers like described above.

[Guest pyromana]

Hi,

For the moment, I have a terrarium (60x35x30 - LxDxH in cm). I bought 2 Grow LED panels on Ebay 3 mouths ago and for the moment, my CP are growing pretty good and fast. My nepenthus is making a lot of new amphora, my drosera adelae has new bigger leaves,..

I'm making a bigger terrarium (100x30x60 - LxDxH in cm) and I bought a third Led panel with 4 LED neons (color: cold white).

I'll make a little reportage with the new terrarium and let you know if the plants fell good inside.

[Tha_Reaper]

I have build my LED grow pannel. Ive made a little photo report.

The Box

The is a standard 40*32*23 cm box. For sale at a lot of interiorshops. I coated the inside with aluminium foil by a lack of mylar foil. I did this for a more concentrated light.

The Lid:

This is the downside of the lid. 7 LEDs are placed there on a star heatsink. I stuck them with a thermal compound to the aluminium slate to get a good surface for the transduction of the heat.

The Drivers power the LEDs at 700 mA, 3,4 Volt. Drivers are connected parrallel to a 230v source.

I stuck the drivers to the aluminium with a dot of sillicon kit (the stuff you use to seal your shower so you dont have to mop the bathroom floor everytime you showered.

And in working order:

I wore 2 sunglasses before i could even take this photo. not recommended to look directly into it without them.

The lid is placed on the box. The Lid will become lukewarm after 30 minutes to an hour, and will cool down within 5 minutes after shutting off the LEDs. Inside the box the temperature will become 5 degrees celcius above the ambient temerature after 4 hours. In the pictures there is a gap left in the led, but since i dont like my room being lid by a cool white light, i place a second slate of alluminium on that gap. there is no ventilation in the box.

Total power consumption: 22,5 watt.

I started some experiments to see if seeds and seedlings sprout and grow faster under sunlight, cf light, or LED light. when i started it up, i had the feeling that this is a bit of a light overkill but if it works, it will definitelly work wonders for my energy bill.

Edited March 1, 2010 by Tha_Reaper