COB LED DIY Build Journal

Humanrob

Well-Known Member
In the very old detached single car garage I'm growing in, the room has a basic R13 wrap. It's a crude maybe late 1930's structure, with no sheathing or moisture barrier, just very thin clapboard siding nailed directly to the outside of the wall studs. It's a challenge to grow out there, with only minimal insulation and wall board it is heavily influenced by outside temps. I'm still learning exactly what times of year I can maintain decent temps between heating (not really used yet...), AC, and the dehumidifier. So far this fall, if the outside temps are above the mid 40's, I need to run an AC or a positive feedback loop will develop and the room will overheat (I'm running a total of about 840w of COBs between two tents in a 13'x13' room).

I keep my exhaust fans running 24/7, always have. It prevents moisture buildup, and Oregon is an inherently spore filled place so I have to keep the air moving to prevent PM. Last winter before I finished insulating the space, I did a run in there with a 600w HPS light in the 3x3, and I took the exhaust from the cool tube and directed it back into the intake, to cycle the warmed air back in. I had a separate exhaust fan and intake circulating fresh air in and out. At this point with the improvements I made structurally and with insulation, using only COBs my tents stay about 5-6º above whatever the room temperature is.

I'm dealing with similar questions about what style of grow would be the best use my spaces. SCROGs are tough in a 3x3. A lot depends on your height restrictions, and whether you are growing Indica or Sativa dominants, and what your ultimate goals are. I have enjoyed my short run/small pot from seed runs, growing hardy little trees that need no support. But now that I'm not doing outdoor grows anymore, I need to up my game on the indoor. It looks like in this space I might be able to get two grows in per year, so I have to squeeze all I can from them. I'm still figuring out what that means.
 

PDX Joe

Well-Known Member
In the very old detached single car garage I'm growing in, the room has a basic R13 wrap. It's a crude maybe late 1930's structure, with no sheathing or moisture barrier, just very thin clapboard siding nailed directly to the outside of the wall studs. It's a challenge to grow out there, with only minimal insulation and wall board it is heavily influenced by outside temps. I'm still learning exactly what times of year I can maintain decent temps between heating (not really used yet...), AC, and the dehumidifier. So far this fall, if the outside temps are above the mid 40's, I need to run an AC or a positive feedback loop will develop and the room will overheat (I'm running a total of about 840w of COBs between two tents in a 13'x13' room).

I keep my exhaust fans running 24/7, always have. It prevents moisture buildup, and Oregon is an inherently spore filled place so I have to keep the air moving to prevent PM. Last winter before I finished insulating the space, I did a run in there with a 600w HPS light in the 3x3, and I took the exhaust from the cool tube and directed it back into the intake, to cycle the warmed air back in. I had a separate exhaust fan and intake circulating fresh air in and out. At this point with the improvements I made structurally and with insulation, using only COBs my tents stay about 5-6º above whatever the room temperature is.

I'm dealing with similar questions about what style of grow would be the best use my spaces. SCROGs are tough in a 3x3. A lot depends on your height restrictions, and whether you are growing Indica or Sativa dominants, and what your ultimate goals are. I have enjoyed my short run/small pot from seed runs, growing hardy little trees that need no support. But now that I'm not doing outdoor grows anymore, I need to up my game on the indoor. It looks like in this space I might be able to get two grows in per year, so I have to squeeze all I can from them. I'm still figuring out what that means.
That's great you have a dedicated garage to grow in. But I can understand how insulating it properly can be a pain in the ass. And really the best solution is to insulate the hell out of it. But there are some specific tricks you can use in a climate like ours. Keep in mind it's actually better to increase R values in the roof/ ceiling first and then the walls. Insulation on the top of the structure is more effective than wall insulation. So insulate the hell out of the roof first and then insulate the hell out of the walls.

In the case of grow rooms it's better to have the moisture/ vapor barrier on the inside face of the walls rather than the outside face. You always want your vapor barrier on the side with the warm moist air, which is the grow room side. In your case it's good you don't have a moisture barrier on the outside. This will allow any vapor that gets into the walls to be able to dry to the outside. Using closed cell foam on the inside face of the walls will also prevent warm/ moist grow room air traveling through the walls. It's also the most efficient way to insulate in your situation.
 

Manuel Smith

Well-Known Member
Thanks. I've found a lot of inspiration from a lot of people on RIU doing really cool shit. The nice thing about a forum like this is that everybody builds off of each other's ideas.
Yes that's what I love about it also.
I used a bunch of ideas already and I'm on a budget but it helps that others give ideas that we can make a knock off version of.
 

Manuel Smith

Well-Known Member
That would be cool. Machinists rock... my uncle is a really good one. But, no I'm an architect. So I really like designing and building stuff.
Oh I'm sorry it's just the way you built things reminds me of the machinist in the welding shop, those guys build anything when it comes to metal.
I'm a welder/fitter so when my funds get right I hope your still here to see what I do and I'll definitely be using your ideas if you don't mind.
 

Humanrob

Well-Known Member
That's great you have a dedicated garage to grow in. But I can understand how insulating it properly can be a pain in the ass. And really the best solution is to insulate the hell out of it. But there are some specific tricks you can use in a climate like ours. Keep in mind it's actually better to increase R values in the roof/ ceiling first and then the walls. Insulation on the top of the structure is more effective than wall insulation. So insulate the hell out of the roof first and then insulate the hell out of the walls.

In the case of grow rooms it's better to have the moisture/ vapor barrier on the inside face of the walls rather than the outside face. You always want your vapor barrier on the side with the warm moist air, which is the grow room side. In your case it's good you don't have a moisture barrier on the outside. This will allow any vapor that gets into the walls to be able to dry to the outside. Using closed cell foam on the inside face of the walls will also prevent warm/ moist grow room air traveling through the walls. It's also the most efficient way to insulate in your situation.
I'll see how this winter goes and decide if I need to insulate any more. Since I have to run the dehumidifier most of the time -- and it produces a lot of heat -- I might not need any more insulation. Also, the plan is to shut down between late December and late February, and not grow during the dead of winter. I'm trying to take notes on what I'm having to do to maintain RH and temps, but every year is different, we've had mild winters and brutal ones since I've lived here.

Here are some quick pics of what I have going now, a few days shy of week 5. It's primarily a breeding run, so all the plants are small in either 2 or 3 gallon pots. There are 4 in the 3x3 (+ one 1 gallon tucked in that I couldn't throw away...). I have no idea once I remove the pollinated branches, how much of a yield I'll get from the rest of the plants. I have seen my pollinating technique was sloppy, and it looks like we'll be getting random seeds from some of the smoking buds. No worries, I'm old enough to remember when all weed had seeds. ;)


11.15_2x4.jpg 11.15_3x3full.jpg 11.15_3x3tops.jpg
 

PDX Joe

Well-Known Member
Oh I'm sorry it's just the way you built things reminds me of the machinist in the welding shop, those guys build anything when it comes to metal.
I'm a welder/fitter so when my funds get right I hope your still here to see what I do and I'll definitely be using your ideas if you don't mind.
Go for it!
 

PDX Joe

Well-Known Member
I'll see how this winter goes and decide if I need to insulate any more. Since I have to run the dehumidifier most of the time -- and it produces a lot of heat -- I might not need any more insulation. Also, the plan is to shut down between late December and late February, and not grow during the dead of winter. I'm trying to take notes on what I'm having to do to maintain RH and temps, but every year is different, we've had mild winters and brutal ones since I've lived here.

Here are some quick pics of what I have going now, a few days shy of week 5. It's primarily a breeding run, so all the plants are small in either 2 or 3 gallon pots. There are 4 in the 3x3 (+ one 1 gallon tucked in that I couldn't throw away...). I have no idea once I remove the pollinated branches, how much of a yield I'll get from the rest of the plants. I have seen my pollinating technique was sloppy, and it looks like we'll be getting random seeds from some of the smoking buds. No worries, I'm old enough to remember when all weed had seeds. ;)


View attachment 4043978 View attachment 4043979 View attachment 4043980
That’s great you’re growing your own seeds. What strains are you breeding? Are you using siblings for just a seed stash or are you trying to create a particular cross?
 

Humanrob

Well-Known Member
That’s great you’re growing your own seeds. What strains are you breeding? Are you using siblings for just a seed stash or are you trying to create a particular cross?

It's a long story, but pollinating started on a fluke for me during the summer of 2016 when my brother accidentally let a boy go, so I collected some pollen. It was from a group of plants I gave him, so I knew the strain was LSD. Some of the crosses I made from that were duds, others were great, but the LSD I grew in my outdoor from that batch of seeds were fantastic plants in every way, from mold resistance to productivity to the high itself. So that got me thinking.

From another angle, a friend gave me a few seeds a while back and he couldn't remember what they were. It turned out to be our favorite strain (of course!), we call it Mystery. An odd set of good/bad luck, the last one I grew in an indoor went pure hermie, and it created a handful of feminized seeds that have all grown normally. Since they are feminized - and I don't want to force another hermie - I'm crossing other strains with that one to try and keep some of its genetics alive.

I also had an accidental pollination in a tent last winter, so I played with trying to make an F2 out of those seeds, and that took up some space this run. It taught me a lot about how much time and energy breeding takes, and not to waste it on random things. I'm purely "pollen chucking", real breeding requires lots of cloning and testing and choosing phenos from multiple samples. My space is so small and I pop so few seeds that sometimes I just have one male, so he's the pollen donor, no real selection process.

It is fun though, and even though my selection is severely limited, I do like the idea of taking two plants from a fresh cross and crossing them again (a few times over time) to attempt to create a more stable line. I've got a few more LSD seeds left and a few more Mystery, so next run if I get one good healthy male LSD I'll be making a fresh cross with those. The whole thing is really challenging given the layout of my physical space, and the results of the efforts unfold over months and years. At this point I'm only doing two grows per year, so the results of each cross will be tested a year later.

Told you it was a long story, and that was the short version! ;)
 

PDX Joe

Well-Known Member
I added a couple of case fans to cool the pin heatsinks. I mounted them at the side of the light case... they're blowing across the pins rather than down onto the pins. I had to switch out the fan driver to a bigger driver that could power the six computer fans. The fixture is ready to go for my winter grow.

fullsizeoutput_1f8.jpeg
 

Tim Fox

Well-Known Member
I added a couple of case fans to cool the pin heatsinks. I mounted them at the side of the light case... they're blowing across the pins rather than down onto the pins. I had to switch out the fan driver to a bigger driver that could power the six computer fans. The fixture is ready to go for my winter grow.

View attachment 4049556
looks awesome, good organization, should be a winner,,, motivates me to get more done
 
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