Canada Grows to the 4 Plant Limit

Discussion in 'Indoor Growing' started by DIY-HP-LED, Sep 10, 2017.


    DIY-HP-LED Well-Known Member

    Strips do look appealing, very high lumens/watt and little required for heat sinking, wish more places than digikey sold them though.
    Nice grow, from the bud pics I'd say yer getting enough lux/par. Know how much lux yer getting at canopy level? Citizen COB prices are coming down and they are a good alternative to cree and vero29's.
    CanadianDank likes this.

    CanadianDank Well-Known Member

    I bought mine at arrow, not digikey and they were a small amount cheaper.

    No clue on lux, and I just swapped that this week, was 600w hps before.
    Dont need a meter to tell ya it's much better penetration and coverage though!

    Yeah th citizen chips are quite affordable, it's th heatsinks and shipping that aren't.
    DIY-HP-LED likes this.

    DIY-HP-LED Well-Known Member

    Ya definately gotta innovate on the heatsink end of things, I using and testing 1" square tubing ($1/ft CDN approx) and water cooling. Ebay CPU heatsink/fans are the cheapest option and will handle COBs driven up to 50 watts with the fans undervolted to run quieter.

    I wonder why someone with a drill press in southern ontario hasn't gone into the custom heatsink business, they should be able to get heatsink extrusions in standard 20 foot lengths for wholesale prices.

    DIY-HP-LED Well-Known Member

    Gen 3 Grow Light Water Cooling Tube Construction
    I cut some 1-1/2" pieces of channel for COB backing plates and tried one on the cooling bar to make sure everything fit correctly. This is a 81 watt Citizen CLU 048 3500K CRI 90 and a cheap holder and I plan on using 5 of them (with 2700 K also) on the 4 foot long test bar.

    Here is what it looks like from the side using a 20mm M3 nylon standoff. On the test and final light I'm using 22mm x M3 brass standoffs and silicone pads between the COB and cooling tube. I'm gonna drill a small hole over the negative COB contact to get some Tc readings from 2 holders. I'm gonna get Tc readings from 2 COBs, one using thermal paste and the other using a silicone thermal pad and see which one I'll use with the final light

    Here you can see how the COB and holder line up with the cooling tube and how much of the COB is hanging over the edge. I cut some small backing aluminum plates, instead of a large single backing plate, so that I could adhere the drivers directly to the cooling tube with double sided adhesive CPU thermal tape. If I mount the drivers upside down on the cooling tube with thermal tape they should be cooled by the lamp cooling system as well. On the test bar I'm gonna mount one 100 watt driver upside down with tape and the other driver rightside up with a wire tie and measure the temperature difference. These drivers often run at over 50 C, so if they can be cooled by the water cooling system that should be better, the cooler the drivers run the longer they last.
    ttystikk likes this.

    DIY-HP-LED Well-Known Member

    ledgardener and ttystikk like this.

    ttystikk Well-Known Member

    He's been trying to blow up a quantum board for awhile now. Pretty funny- the board has thus far resisted all attempts to cook off, even with 450W applied to it lol

    ledgardener Well-Known Member

    Heheh. Yeah I think the next attempt will be without a heat sink. It's kind of cheating but if I can't do it with a 600W driver then I've got to resort to special tactics.
    ttystikk likes this.

    Yodaweed Well-Known Member

    Why don't you upgrade your grow area to a larger area then?
    DIY-HP-LED likes this.

    DIY-HP-LED Well-Known Member

    I am building another 4' long water cooled light using the above design to cover another 3'x5' grow area in the flower room that I'm gonna use for another strain. I'm gonna limit the power used over the main grow table to a kilowatt or less and use about 800 watts over the new area.

    DIY-HP-LED Well-Known Member

    Gen 3 Grow Light Water Cooling Tube Construction & Test

    I finished a test lamp using a 4 ft long water cooling tube made from 1" square architectural aluminum tubing with sharp corners. One one end of the tube has a pair of Citizen CLU 048 COB's with cheap plastic holders, the other end has a pair of warm white 100 watt flood light COBs. I'm gonna take some Tc measurements off the citizen and floodlight COBs and the 50 watt drivers as well. One of the citizen Cobs and one of the drivers is using a silicone thermal pad to facilitate thermal transfer, one driver is mounted the regular way and I'm gonna see how much the cooling tube can cool the drivers as well.

    An end view with the floodlight COBs and silicone thermal pad material

    I held the upside down mounted drivers on tight with nylon wire ties and used a silicone pad under one driver and the other two used medium quality silicone thermal paste. One driver is mounted the usual way and no effort was made to thermally bond it with the cooling tube.
    20171110_200102.jpg 20171110_200102.jpg

    I'll but some black tape on the drivers and tube to take infrared thermal readings and I use it to with the K type thermocouple too. I drilled a hole in the plastic Citizen COB holder over the negative contact to get some Tc readings and I'll get some off the floodlights as well

    Using WAGO connectors makes the job a snap and since I'm gonna take the test lamp apart, after I confirm that the cooling tube is up to the job of cooling both floodlight and Citizen COBs, it will make that easy too.

    Tomorrow after I feed the girls I'm gonna wet test the lamp on the bench and take some thermal readings after she warms up a bit. If it cools the CBs the way I want, then I'm gonna rebuild my big water cooled rig using the new 6' long design. I've built 3 x 4 ft long 1" square cooling tubes and the test lamp is one of the tubes, I'm gonna expand the grow with another 3 x cooling tube 4 ft long water cooled lamp using leftover drivers and floodlight COBs. There's unused space in the grow room, capacity in the lamp cooling system and spare COBs and Drivers laying about. For now there's going to be a sativa dominate (Moby Dick) going in the space, but something high in CBD would be nice if I could get something stabilised or even a clone. I'll have a 4' x 2' 750 watt water cooled lamp made with 3 cooling bars and a cob spacing of around 11", over a 3' x 5' area. I might add 80 to 100 watts of 4000K LED strips to this light as well.

    Gen 3 Test Grow Light Water Cooling Tube Test Results
    The results of the wet bench test confirm that I can use these tubes to build my water cooled grow lights, Tc temps in the mid forties for both the Citizen and floodlight COBs using either thermal paste or silicone thermal pads between the COBs and the cooling tube. The coolant temp was 26 degrees celsius, the ambient temp was 25 degrees and the lamp drew 182 watts at the plug, because 3 of the drivers only draw 44 watts each and were an ebay scam (i got a refund). The upside down mounted drivers that were cooled by the cooling tube ran 15 C cooler than the one that was mounted right side up, so the enclosed drivers on the final lamps will be mounted upside down and will be cooled by the tubes too.

    You can use 1" square aluminum tubing like that shown as a grow light water cooling tube and mount 28mm square quality COBs with a holder or screws on Chinese floodlight COBs and also use the cooling tube to significantly (15 C) cool the drivers as well.

    Each 4' long 1" square tube cost about $4 for the aluminum tube and 2 x $2 CDN for the brass PEX end fittings,
    or $8 per tube x 3 tubes= $24 CDN for a 4'x2' water cooled light rig. Some silicone caulking to seal the ends of the tubes, a couple pieces of aluminum angle, some plastic fittings and hoses and something to dump heat out with on the other end of the cooling system.

    This is about as cheap as water cooling gets and it's cheaper than air heat sinks for a large light rig, my new lamp described above will have a total of 15 COBs, that's a lot of pin heatsinks!
    ttystikk likes this.

    DIY-HP-LED Well-Known Member


    DIY-HP-LED Well-Known Member

    Four Foot Long Gen 3 Water Cooled LED Grow Light
    I've started constructing a four foot long Gen 3 water cooled LED grow light by stripping my 24"x24" water cooled light to use the frame and components in the new light. I removed the 24" cooling bars and stripped out the electrical box.

    Three 100 watt drivers on the left and a 100 watt on the bottom right next to it is a 50 watt driver and the metal box in the top right is a 12 volt fan power supply. Over half of the AC side of the lamp is already wired with WAGO connectors. I'm holding a 50 C thermal cutoff switch down onto the center cooling tube with a clamp until some epoxy sets, this is a safety feature to shut down the lamp in case of a cooling system failure.


    I have one COB mounted in the middle of the center cooling bar under the electrical box, it's covered in masking tape for protection during construction. I used 1" mending plates from the local dollar store to hold the 3 X 4' X 1" square aluminum cooling bars to the support frame using the original bolts

    I mounted six flood light COBs with thermal paste on one end of the lamp using M3 x 35mm screws and nuts. I cut some square pieces of aluminum as back plates to mount the COBs on, I was going to use 22mm x M3 brass stand offs, but they haven't arrived yet, though the 35mm x M3 screws did and work fine.

    Tomorrow I hope to have the rest of the drivers and COBs mounted, then I can wire up the COBs. I might put 6 X 20 watt 4000K strips on the this lamp as well, it depends when the drivers arrive.
    ttystikk likes this.

    DIY-HP-LED Well-Known Member


    DIY-HP-LED Well-Known Member

    Four Foot Long Gen 3 Water Cooled LED Grow Light
    I finished the four foot long 15 COB water cooled grow light today and had it on for first light this afternoon for a quick dry test. The lamp uses 690 watts total from the plug, it should use more power, but 3 of the 50 watt enclosed drivers on one end were an ebay scam and only use about 44 watts each instead of about 54 watts each.

    The lamp has two separate zones, one end of the light has 9 COBs switched and the other end of the lamp has 6 of the 15 COBs switched, this way I can use it with a single plant or two by switching one one or both ends of the lamp. I'm thinking of adding the 4 x 23 watt 4000K strips to the outside bars

    I'm using 15 x 100 watt flood light COBs driven at 50 watts each, 3 bars x 5 COBs per bar. The lamp is 4' x 2' and is designed to cover a 5 x 3" grow area

    All closed up and ready for bench testing, I got one end plumbed with hose and fittings, just gotta put a couple of plastic PEX elbow and a "T" fitting on the other end then connect it up to a pump and reservoir

    Here are some construction details.
    I was almost finished and out of screws, when the mail arrived with 50 x 22mm long M3 brass standoffs, so I used them on a couple of COBs, they seem to be easier to work with and might be a better choice for mounting COBs

    I used four threaded (ready) rod connecting nuts as legs to stand the lamp off the bench or floor when setting it down. 2" steel mending plates from a dollar store were used to mount the cooling tubes to the aluminum angle frame, I used 1" pieces of 1/4" vinyl hose on the bolts to make up the gap between the tube and 1/4" bolts.

    On the left of the electrical box between it and the aluminum angle frame, there is a 50 C thermal cutoff switch mounted on the center cooling tube and wired in series with the power switches for the drivers. I connected up the AC side of things with 4 x WAGO 5 way connectors, the wiring is a bit of a mess, but it's safe
    I hope to have the lamp ready for a wet bench test tomorrow morning and perhaps installed in place tomorrow as well.
    Last edited: Nov 26, 2017

    ttystikk Well-Known Member

    One of the biggest problems I had with my water cooled arrays was in getting the water to flow evenly through all the channels. I had plumbed them in 'parallel', so there were a dozen circuits between the inlet and outlet manifolds.

    In the case of the light above, I'd have been very tempted to input water at one end of one bar, then use two U shaped lengths of tubing to connect the first to second and second to third, then to one outlet port at the far end of the third bar- thus plumbing the fixture in 'series'.

    The advantage would be to ensure that all bars get the same flow and that it effectively scavenges air out of the fixture.

    Your thoughts?
    Last edited: Nov 26, 2017

    DIY-HP-LED Well-Known Member

    I find running water back through the the center tube or vice versa works well enough for a three tube design if the flow rate is high enough. I only need a thermal cutoff switch on the center tube and when I bench test it I'll check for temperature differences between the tubes, I only expect a couple of degrees between the inlet and outlet temps.

    I really like this new design, it's very light, easy to build, cools the COBs very well and is cheap. The cooling tubes and brass fittings only cost $8 CDN per 4 foot long tube and the tubes and brass fittings for the entire lamp were just $24CDN. Brass standoffs are $8 CDN for 50 ea on ebay and the circulating pump from ebay to run the cooling system is just $12CDN and has a very good flow rate at a 10 foot head.

    For your vertical grow setup, you'd just use two COBs back to back with the cooling tube sandwiched in between, instead of using a backing plate, you'd just use another COB.
    ttystikk likes this.

    ttystikk Well-Known Member

    That would work great if the module were designed to only run between plants, but I wanted the versatility of being able to run other configurations. It's still a good idea and I did think about it. Maybe if the two sides were on different circuits?

    DIY-HP-LED Well-Known Member

    These bars are so cheap to build that you don't need to worry about mounting COBs on both sides, just use them with COBs on one side and alternate if the grow is vertical, or reconfigure for a regular horizontal as (God intended:smile:) grow. Mounting COBs on both sides of the cooling tube is a cool, efficient and space saving thing to do though, almost worth making up one to take some pictures, would look real cool!

    I figure these kind of aluminum cooling bars should be cheap as dirt to build down in Colorado, we pay through the nose for everything in Canada it seems.
    ttystikk likes this.

    ttystikk Well-Known Member

    I'm a bit nuts about modularity of components so rather than constructing special purpose units, my own design philosophy is one of designing the simplest unit that can be replicated and positioned to handle the greatest number of situations.

    That's why I have a whole slew of 225W modules; they can be arranged in an infinite number of ways to adjust light intensity, coverage, horizontal vs vertical orientation and I'm sure more I haven't even thought of yet.

    A double sided bar would work fine. IME, it wouldn't save significant space or perform appreciably better. It would trade away flexibility for one application, without gaining enough performance to be worth the trade.

    I like this conversation; it's nice to discuss the finer points of water cooled lighting design!
    redi jedi

    redi jedi Well-Known Member

    Why water cool LED's in the first place? I thought these things were efficient and ran cool?

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