DIY COB LED, firesafety?

I used to grow/smoke herb for years, but i stopped after getting married.

I used to grow herb using 2 small T5 TL bulbs, and for the flowering stage i used to switch to a 100 Watt HPS. But after a couple of years of inactivity, i threw away my HPS ballast and lamp...

Several years ago, my wife got diagnosed with fybromyalgia, she takes a cocktail of drugs to help her with the pain and sleeping problems. Thanks to our MD, she tried CBD oil and it helped both for the pain and the sleeping problems.
So, now i finally have an excuse to start my hobby again, but grow some of that 30:1 CBD:THC weed indoors instead of the strains i used to grow .

My main problem (or is it a question) is that during the week (monday-friday) we live in a tiny rental appartment (due to my wife's illness we had to live closer to our jobs) but we still own a big house in the middle of nowhere. This is where we spend our weekends. This weekend house has a free-standing garage that's hooked up to the electricity net. The garage is made out of bricks. However, I won't be able to tend to my plants from monday morning to friday evening. The lights themselfs can be plugged in to one of those mechanical timers, the food/water can be delivered by one of those ceramical devices that are hooked up to a bottle of water... But i'm most concerned about fire-safety... I don't want to come home friday evening to find my garage burnt down.

I already did some of my homework, can somebody point me in the right direction if i made mistakes?

setup 1:

• Cree CMA3090-0000-000R0H0A30G : 11720 lm, 3000K, 174 W, 115° viewing angle, 68 V foreward voltage, max 2,4 A foreward current
• Meanwell driver LPC-100-1400, constant current, 100.8W, 36->72V, 1,4A, ip67
• BJB LED mount 47.319 for cree CXA 3035 en CXA 3070 (apparently, the CMA3090 has the same formfactor, if i'm not mistaking)
• Thermal paste or thermal glue between the COB and the cooler
• as a cooler, i'd order something like this: https://www.aliexpress.com/item/32984094320.html
• a 12v 1.25A PSU to power the fan

mogelijkheid 2:

• Bridgelux BXRC-60E10K0-D-73: 11370 lm, 3000K, 76.8W, 112° viewing angle, 36.6V, 2.1 A
• Meanwell driver NPF-90-48, CC+CV, 28,8 -> 48 V, 1.88A
• no led mount (can't seem to find one), so i'll just solder everything together
• thermal glue
• dan, als koelvin + lens zou ik in china iets zoals dit bestellen: https://www.aliexpress.com/item/32984094320.html
• as a cooler, i'd order something like this: https://www.aliexpress.com/item/32984094320.html
• a 12v 1.25A PSU to power the fan

What do you guys think? Is it worth a shot or will i burn down my garage by doing this? I know you can buy those pre-assembled kits, but building everything is half the fun

Maybe start with whats your budget and the size of space.

If youre worried about fire then maybe cobs with active cooling isnt the way to go, especially from AliExpress. Cobs put a lot of watts thru a small chip which means much higher temps. There are solutions with boards which means no heatsink needed.
Also which region are you? Eu, Muricahs?

My cobs are running at 132.8°F on the face. 100.1 on the sink. 106.6 on the driver. 51.2 volts.

Current air temps, 81.6°f......with a heater.

Buy a fire extinguisher if you're worried.

Thanks for the replies so far! I'll try to give a short reply to most (if not all) questions:

I don't really have a fixed budget, it's a hobby, it can cost a little bit of money... On the other hand, i'll only be growing high CBD/low THC weed to create eadibles for my wife. She uses ~2 grams/week (low dosage in the evening to ease hear pain and help her sleep), so growing 100-150 grams a year will be sufficient. Spread over 3 grows, each grow should only yield 40 or 50 grams. That's why i was going for a single COB, and the investment shouldn't be massive (if I invest 1000€ for 100 grams/year, i might be over-investing).

I don't have a growtent (yet), I was thinking about building a growroom using plasterboard, so i can make it as big (or as small) as i want... On the other hand, buying a tent will probably be easyer. In order to grow 40-50 grams, i tought having a 50cmx50cm room with a ~100 Watt COB would be more than sufficient, but i'm defenately open for suggestions.

I'm from western Europe.

Reading your replies already makes pretty clear to me that an actively cooled COB isn't the best idear when talking about fire safety. Buying a fire extinguisher won't ease my mind, since i won't be home monday-friday, so there'll be no-one around to use the extinguisher if a fire was to start. I have a friend who installs automatic fire extinguishers in server-rooms (professionally), but i guess paying several thousand euro's for an automatic extinguishing system would be overkill for 100 grams/year, even if it's a hobby and it's not meanth to turn a profit

What other tips could you guys give me? I know from the good old days that an HPS lamp and balast can get really hot, so a HPS will probably be worse than a COB... Should i go back to fluorescent lighting, or go for LED strips instead?

Thanks in advance

not tested myself, but you get the idea.

100W, that is it? Do you have Dollar (Euro?) stores there? Ten 100W bulbs and lamp holders would give you what you need, I paid about $1.25 for them. The holder is a little more, I actually took the guts out of the bulbs and mounted it on some aluminum rails.






With the lamp holder you should have no worry about burning down the garage.

dont you have a nice nacked 115V AC without any isolating transformer in between there using bulbs without enclosure?
in case of migro even 230V.
the menawell drivers do all have isolating transforners as the leds they drive are seldon in a encapsuled enclousre, so the layer of protection (needed for a FC/CE) comes by the transformer, the led bulbs (who skip the isolating transformer for cost reasons n space mostly) rely on the plastic enclosure as isolation to be able beeing sold to endcustomers.
you better keep your head away from them when working on the plants, would make me more sorrow then a fire.

I can not speak for Migro. The exposed high voltage terminals on my lights have been insulated with electrical grade silicone. My point was that for a hundred watts in power you could get a few lights and stick them in holders. The point of the vid was to show that you can get a decent amount of light from regular light bulbs.

true you can get ppf for cheap with normal bulbs, if your contacts are covered and you know its simply your 115V, all ok.
i just dont like to see them uncovered and then contacts exposed completly, thats really dangerous and at the very least people need to know the manufactorer put them completly in pl,astik for some reason..

i didnt made the math but some led strips on digikey n else arent much more then some bulbs, maybe even cheaper if you consider the diode count.
bulbs are unbeatable easy to get and holders are often in a household allready, point for them.

They make grow room self contained extinguishers with a sprinkler head...... Just hang and done.

If you only want 100 grams a year, you can get that with a 4x4 tent, two plants, a cheap mars or the like, all on one grow.
If you grow the cbd strains for wifey, why don’t you get to grow real weed for yourself? Doesn’t seem right.