Thermoelectric coolers on DIY LED's?

My idea for this thread is simply cooling DIY LED panels effectively and for cheap. You can always scour the internet (like I have) for the right sized extruded Aluminum job, but that could get expensive quickly especially after considering the number of and size of the panels you'd like to make. The weight and sheer size also has to be considered if you ask me. I just found/thought of this one so I'll throw it out. Comment, or if you have your own idea I'd love to hear it. I know this isn't rocket science, but I haven't seen much variation in this department and just wanted to stir things up a bit.

Found these:
http://www.ebay.ca/itm/wdm-2pcs-Aluminum-heatsink-core-PCB-for-36-pcs-HP-LEDs-in-seres-225-193mm-/170843835766?pt=LH_DefaultDomain_0&hash=item27c7160d76
The eBay seller has other models similar to what you see here, but this is the largest one (holds 36 LED's in series) that they carry. It not only looks very similar to what stardustsailor has been using on the Astir panels, but it looks 100% useful in my opinion, and it's cheap to boot! I've bought three of these so I'll be able to comment on their construction later (hopefully soon), or someone with an Astir panel could chime in, I suppose. Also, keep in mind that many of the cheap 1W Chinese LED's (including the ones sold by this eBay retailer) all run at 350mA irrespective of being Blue, White, or else. I know more expensive Blues and Whites can run at 700mA, or what have you, but if going this route you can string Reds, Blues, Whites, pretty much anything other than IR and UV I believe, together and run them all in series from a single LED driver. (Make sure they are all 1W or all 3W, don't mix 'n match) I don't think the voltage difference between colors will make much/any difference. Moving on.

So I stumbled upon these things:
http://www.amazon.com/TEC1-12705-Thermoelectric-Peltier-Cooler-40mm/dp/B002UQKEU8/ref=pd_sim_pc_4
and it got me thinking about the Kessil's and their little heat exchanger inside the H350's. I guess these thermo pads have a cold and a hot side, so you thermal epoxy the things down in the right orientation (and voltage direction) onto those "heatsink cores" that I linked you to, and then you thermal epoxy a much smaller and cheaper heatsink onto the hot sides of the pads. Maybe even install a fan onto the heatsink as seen here:
http://www.homebrewtalk.com/f51/diy-thermoelectric-temperature-control-27524/

So, $8.95 for the thermo pad which qualifies for Amazon Prime. I'm guessing one might not cut it for a 225 x 200mm "heatsink core," though, which could put us in a tight spot. After that you'd need a correctly sized heatsink. I'm hopefing that would be in the $5-$10 range. You'd need a PSU to power the thermo pad (another $5-$10, I suppose), a fan if you choose to do so, and lastly a PSU for the fan depending on what you just decided.

This all sounds hella annoying to me and almost not worth the cost, time, effort... not to mention the tangle of wires. :/ Are heat issues even that bad that they require a thermo pad, heatsink and computer fan?! I guess I'll just wait and see what you guys have to say about it. Perhaps you can take things somewhere I couldn't.

Oh! And what about Aluminum cooling pads for laptops instead of the thermo pads and heatsinks? Most laptop pads are just slightly oversized for the "heatsink cores," and I'm guessing a little PSU for the fans would be pennies as well as easy to wire. That's another one, I guess.

Anyways, if you're still with me, thanks for humoring me, and hope to read your contributions soon.

I believe the Astir team shoot for their panels to maintain passive cooling.

IMO, with the right size heatsink and a cpu fan, you shouldn't have problems.

Hi Bumping. Pretty cool (ha-ha) but extreme (77 watts!) way for some cooling when you could just use more efficient LEDs and run them at a lower amperage I would think. I guess if it can run your rig so cool you can replace an air conditioner/multiple fans then it may be worth it. Still it's a cool idea that may have it's application, something like cooling to keep the diodes output within certain parameters under extreme heat. If it can increase your harvest then it may be worth it to the commercial LED grower.

Plus wouldn't it have some effect on your grow room humidity? It would make it drier, right? Could be useful to some. And maybe reek havoc on your rig. Yikes!

Also, your LEDs are gonna have a fun time if it fails

Yup, passive cooling is tried and tested for this application. Nothing wrong with it once you get past initial cost and weight as far as I'm concerned. And I don't mean to detract from its simplicity or effectiveness (or Astir ) by any means.

These thermo pads have an operating range, you don't have to run them at max (77W) I don't think. The manufacturer suggests 50W, and even that might be too much? No idea how much heat 36 x 1W LED's at ~350mA puts out, how much heat these thermo pads can mitigate per watt, or even what temperature the LED's are most efficient at! Also, it won't change the humidity of the room (so long as you don't get frosting on your panel!) or even the ambient temperature because, to my understanding, it puts of as much heat on one side as it soaks in from the other. Sort of a Newtonian thing going on here.

If the thermo pad fails, yea, scary situation most likely. No idea how long their life is either, or how long you can run one continuously w/o undue stress on the unit.

There's an eBay seller that stocks these claiming that they sell in bulk and can help with questions and/or large orders. I'm gonna shoot them an email and see if they can answer any of these questions (life span, operating current, efficiency, etc).

Edit -
Interesting information here.
http://www.ebay.com/itm/THERMOELECTRIC-PELTIER-COOLER-HIGH-PERFORMANCE-MARLOW-SP1848-MADE-IN-THE-USA-/181044387629?pt=US_CPU_Fans_Heatsinks&hash=item2a27161f2d
And there are Chinese versions of these that are selling for ~$4 shipped on eBay.

Edit 2 -

How cold does your unit get?
Our CP1-12726 has a DTmax of 68 deg C. This is the greatest temperature differential that can be achieved between the cold and hot sides of the device.

How many hours can you run one of your units continuously without damage?
Peltier modules like to be powered continuously as opposed to being powered on and off. With that being said, damage is typically the result of MOISTURE, SHOCK and VIBRATION, PHYSICAL DAMAGE FROM IMPROPER MECHANICAL MOUNTING or INADVERTENT OVERHEATING.

How many hours will one of your units run in its entire lifetime?
The MTBF (mean time before failure) is on the order of 200,000 hours with more than 90 percent of failed modules being the result of mechanical abuse or overheating.

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