What to supliment my CXA3070's with? Epileds EPI4542?

Hello all,

Please be gentle with me as I tread softly into the realm of LED lighting.

I am looking to do a bit of experimentation with LED's in my grow, initially swapping out one of my three 600w HPS globes. I've purchased 5 CXA3070 3000K AB bin COB's. I'm looking at heat sinks at the moment but unfortunately in Australia good (and cheap) heat sinks are few and far between. Ordering in from the US is going to cost an arm and a leg. I've managed to find a few that will be quite cheep and as this idea evolves in my mind I am realizing I can get a wider heat sink and look at suplementing the CXA's with some red/blue lighting as well.

I managed to stumble across one of those cheap and nasty Chinese sites that had a very interesting COB LED. It's by no means cheap (about $100), but looks fantastic. Or perhaps, I am just falling for marketing etc.

It is an Epileds 117W 430um/660um COB.
50 x 660um chips
10 x 430um chips

It seems to only be available from the one place that I can see, which I won't post the URL, not sure if i can but a google search will get you there. Just search EPI4542.

I was wondering if anyone had experience with this chip (cant find anything on this site, or others) or what peoples thoughts were?

Is this chip a waste of time?

Which red's/blue's would be the current "Bee's Knee's"?

I am sure i will figure that last question out as I continue to brows the site but feel free to comment.

I'm also wondering if anyone has done under lighting with LED's? I was thinking of a long skinny heatsink/cob set up upside down slightly higher than my pot height. Of course, the fins on the heat sink would trap hot air so it would have to have fan's under there as well. I have 2 row's of 4 flood and drain pots so a strip in the middle would fit well. It usually ends up like a hedge in there and a bit of light under side might go well.

Sorry for a long, jumpy post. Just getting excited about playing with a soldering iron again. I am sure you all know that I mean.

AM.

I'd stay away from Epi. Anyone doing DIY seems to go with Cree, Vero, Osram, Phillips. I supplement with Cree A19, BR30 9.5w (60w equiv) and PAR30 Spot/Flood 18w (90w equiv). These are replacement "lightbulbs" sold at Home Depot. Easy to install. Just hang our mount E27 screw-in lightbulb holders and swap bulbs in and out (2700k, 3000k and 6000k). They're about 90 lumens per watt (after removing the gummy coating on the diffusion globe). 10 year warranty. The A19 is about $7 US per bulb.

Someone else (another forum) uses extremely inexpensive "lightbulbs" sold on AliExpress made from SMD5730 diodes. About $2 per bulb. I've ordered some. They're about 100 lumens per watt, probably due to being in clear globes instead of frosted diffusion globes like the A19. Search for "BuyBay 5730" on AliExpress.

I wrote up something about this on my blog at RIU (same username), but it's not viewable without being logged in there.

well everything we say is opinion, but I wouldn't buy a chinese cobb...

are you wanting to replace the 600 or just messing around and don't care how many watts? if you want to replace, you need a couple heatsinks and a couple cobbs to make it efficient and worth while.

under canopy lighting, never seen anyone do it, it's possible and philips makes a LED for that, but with all the hassle of having a light down there, I'm against it.. but do it if you like.. who knows you might invent the newest thing

red and blues, forgot off the top of my head, but supraspl over at RIU knows. I think the blue is luxeon.

Go with these heat sinks.

http://www.newegg.com/Product/Produ...xEKn9--678wVig7PG0LwHQLnv-nBSvVMSIhoCVPjw_wcB

Use reflectors for those COBS.

Supplement with cree or osram. Cree for efficiency, and osram for cost.


But if you just want all that light, go with the epi. I has a lot of power and light.


Create a stack of peltiers, 3. One on a copper shim, the other two, sinking the one peltier.


Now you have a 12v fan powered by 3 peltiers. (there's one of my ideas)


Eff the haters saying LED's use fan power. Hello HPS uses a wasteful ballast.

Hello everyone, thank you for your replies.
I will try and do you the curtosy of replying to all have given up their advice.

az2000: thanks for the advice mate. I'll definately check out your blog over there and see if I can steal any of your ideas. Much appreciated.

habeeb, Yes I am not too concerned with how many watts. My main objective is to reduce heat inside my tent while (trying) to maintain yield. When weighed up with the other advantages of not having to replace globes as often and being able to spread the light sources around LED's become appealing. At least enough to try some experiments with.

I was stalking RIU a little, and they seem to have some knowledgeable people over there. Thanks for the lead.

tenthirty: I was trying so hard to source those heatsinks in Australia but failed. There were some other CPU heatsink's I could get my hands on but non looked as strong or as efficient as that one. It's US $9 with free shipping but factor in exchange rate and international shipping and the cost is now $31.32 and since I would need 5 of them, thats $156 (they don't appear to adjust the shipping cost when bought in bulk but I havn't rung them to ask).

And since heatsinks seem to be so hard to get in Australia, I even toyed with the idea of using square aluminium tube and mounting a fan on the end to blow air through it. Currently I have a spreadsheet with heatsinks broken down into costs per meter. On average looking at $120-$160 a meter but just ali square tube comes in at around $16/m so at some stage I will try that to see how effective it is. Maybe that will be my under lighting strip run between my two rows of 4 pots.

For now, it may be a case of an ebay/aliexpress heatsink. No fancy T-Slots or anything but I've got some ideas on how I will use it.

devilgoob:
I couldn'd find any reflectors for these cob's. Perhaps I was not looking too hard. The guys over at the other place all seem to run them with no reflector/lens. I think a reflector would be handy at least. If I was to use a lens I would want about 90 degree i think. I've seen some of the COB comercial lights out there using the 60 and they mount the fitting way up high. Apparently bringing it down too close causes a fair bit of light bleaching. They also tend to sell to customers who grow shorter stature plants (UK) but they will fit 90 deg lenses for Australian and US customers who seem to want them.

Interesting thought about the peltiers. I actually had to look them up as I didnt know what they were. Familiar with thermocouples but had not seen a peltier. I did stumble across a remote radio station from almost a century ago. It had the reminance of something called a thermopile. I was fascinated with it. It appeared to be gas bottle storage and a burner under a whole heap of thermocouples (known as a thermopile). When the battery voltage dropped too low the burners would ignite and heat the thermopile, producing power to re-charge the batteries. This was in the hills of Western Australia where there is a real risk of bush fire's wiping out houses so you can imagine they decommissioned this as soon as solar became available. Old technology, but I started to wonder if there was a use for it today. Perhaps some kind of rocket stove heating a thermopile...

Thank you everyone for your replies and when I get my shit together I'll start a little thread and share some photo's.

Have a good day.

AM

i love when people say dont buy chinese leds...cree is chinese yo lol

Dion said:

i love when people say dont buy chinese leds...cree is chinese yo lol

Click to expand...

Cree owns and operates factories in China, as well as one in the US (where presumably they work out their best practices, standards, etc., to be practiced in their offshore factories).

I think people are talking more about comparing Nike shoes to a pair of no-name shoes hanging off an end-cap at Walmart for $7.99. Both are made in China, but the Nikes to higher requirements.

If there weren't a significant problem with epi-whatever diodes produced haphazardly across China, their government wouldn't be mandating that the industry clean up its act this year.

Hopefully things will get better. That would be a win for consumers and also put a fire under Cree, Osram, Phillips to innovate to stay ahead.

back with more..

yes we mean cheaper products, as in talking of chinese... whats produced in america?????????

for anyone interested, blues should only be used if on a separate driver for veg.. no flower

red, I forgot again... haha.

for heatsinks I would check out aliexpress, you will have to wait 2-4 weeks for delivery from china but much cheaper

I buy all my drivers from there too, and heatsinks can be found pretty cheap if you know what you are looking for