Looking for light suggestion for my situation.

I've been reading and reading and I still don't know shit so I'll ask the experts here. My grow room (for my first grow) will be in a 4.5'x5'x8' room that I'm building in my garage. It's a seperate structure on its own with 2"x4" walls, roof and floor all insulated with a vapour barrier. There will also be another room above with the same length and width but a height of just less than 3'. I was planning to make this my veg/clone starting room with some T5's. I have an AC Infinity Cloudline T6 with a carbon filter for ventilation. I had planned on venting this outside the garage in the summer months and inside the garage during the winter months to conserve heat. My garage is insulated and attached to the house but it's not heated yet and winter gets pretty cold in Canada. My original plan was to heat the garage with a tube heater but with COVID hitting and being out of work I don't know if I'll be able to swing the heater this year. I was set on some Kingbrite or Meijiu lights before shipping costs sky rocketed and more recently I was looking at building my own strip light fixture. My concern is that LED lighting won't be putting off enough heat during the colder parts of the year and that an LED would be wasted in all but the warmer months. I do have a 1000watt baseboard heater to supplement heat during the colder months at night or whenever it would be needed. I'll build a small air intake in the side of my room that will be filtered and light proof as well. I'm going to check on some possible freebie fixtures tomorrow that would be HPS or CMH (not sure if they're single or double ended). There may be some 347V CMH so I don't know (without running the numbers) if adding a transformer would be worth it. I may be able to get one of those for free as well, I'm not sure yet.

I figure before I pull any more hair out deciding on LED lights I should see if it's even worth it with the temperatures I'll be experiencing. I was thinking a 1000w or two 400w fixtures if I go the HPS/CMH route.

Sounds like a question for @Renfro Good luck!

A 5 foot tall flowering space isn't an idea I would recommend.

The thing about garage grows is they usually get mega hot in the summer, making HID lighting prohibitive. The LED has issues with the cold winters.

If you must grow in the garage I suggest figuring out which season you can deal with the energy costs of either heating or cooling. The other option that many use is to run LED in the hot months and HID during the cold months.

I have a summer home up by Labrador, in Sept-Îles, Quebec and I use to have that seasonal problem. So in my garage I built my grow room up against the back wall of the garage and then got up into my attic and put a 3-way duct tube that I can manual open from within a closet that is positioned in-between my garages back wall and my home theater room. So when I have plants growing in my grow room I open that vent and the houses central h/ac keeps the grow room at 70f / 21c no matter what time of year it is up there! But if you can't do something like that then you will need to do what
Renfro said, use HID lighting in the winter, and LED(s) in the summer to manage your seasonal grow rooms heating / cooling issues.

@Renfro Do you mean a 5' flowering space once I put everything in the ceiling? I was guessing it would be better to have an 8' and 3' space rather than an 11' tall space. If a single space seems like a better idea I'm definitely open to it. I may have a hard time reaching the ceiling if I do a single space though unless I build a higher door into the structure. That was my plan with the 3' space above. The upper space would be accessed from the stairs that lead to the door into the house.

My garage faces north so it's always cooler than outside. Earlier it was 22°C outside and the garage was at 16°C. I'm sure when we get up to 30° for a week or two my garage will be closer to 25°. This is where I'll bring you in @piratebug as you got me to thinking of drilling inside my house again so thank you! I'm just on the other side of a closet but I didn't really want to break through the firewall there into my 3 year olds closet. The more I thought of it I discovered I can hole saw through a specific spot in a joist (1/2" plywood) that extends out from the house to end up in my furnace room. I'll put a back flow piece in as well. This will work even better I think as I won't have to take fresh air in from the garage and my house has a furnace and central air. Because I have a 6" exhaust I suppose I should have a 6" supply, air balancing is not my area of knowledge. Or do you think a 4" would be better for maintaining back pressure. My biggest concern is an smell getting back into the house. Wife is not a fan unfortunately.

I managed to score some free lights today. A 185w rated 2x4 that has 6 samsung strips https://www.digikey.com/product-detail/en/samsung-semiconductor-inc/SL-B8T7N90L1WW/1510-1351-ND/5958910, another fixture 70w I believe with OSRAM PrevaLED (I don't see other markings on the board that line up with anything), and a 117w 3500k 12000 lumen LED fixture that's fairly compact like a high bay fixture. Between those with some re-arranging I figure I can at least have my veg light once I get the room finished. I'll vent outside in the summer and into the garage in the winter to maintain as much heat as possible. I have a 1000w baseboard heater I'll still throw in, in case the 6"/4" supply duct can't keep up.

I priced out building an LED fixture before using Bridgelux BXEB Gen. 2 4' strips. $565 with 40' of 1"x1" aluminum L bracket. They are much cheaper than the Samsung strips so even with an increased amount of strips the overall price is much less. The downside is that I would need more aluminum if I wanted to heat sink them all which isn't cheap I was going to have 10 strips on each "half" so 2 - 2'x4' fixtures with 10 strips each, powered by a MW-HLG-320H-42A each. The drivers would be just inside the door so I could easily dim them. This way I'd be running at 765mA each (roughly) max per strip and I should not need a heatsink for each strip. I can always get empty fixture shells (steel) to mount the strips on as well for something. They'll have fans blowing on them as well. My biggest concern is thermal runaway so I had started to look into how to combat it but I hadn't priced anything out. I want my fixture to be safe so I don't burn my house down so whatever the safest end product is I'll do that. The cheaper the better and I'm handy so I don't mind getting my hands dirty. Looks like a fun project to be honest.

Edit: I forgot to say, I would look at adding far red and uvb for flowering as well. At that point I almost should buy from China. I would really like to avoid that. Trying to support as local as I can.

Squirrel_Master said:

@Renfro Do you mean a 5' flowering space once I put everything in the ceiling?

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Consider, height of your pot, height of the light and hanging hardware, distance between light and canopy (usually another 30 inches with most LED). Save some space for growing a plant without having to keep it 12 inches tall lol.

Renfro said:

Consider, height of your pot, height of the light and hanging hardware, distance between light and canopy (usually another 30 inches with most LED). Save some space for growing a plant without having to keep it 12 inches tall lol.

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The smaller space may be used for storage as well but I see your point if there's a 12" tall pot and a hanging light. I thought of it with T5's and the early part of vegging. Seemed like a good idea but I haven't done this before so I'll take the advice of experts here. I wouldn't want to go from 8' to 11' unless there was a real advantage because I need every inch of storage for all my family's crap lol.

After healing from an injury my room is nearly built now, it ended up being 4'x'5'x10'. The exterior is 2"x4" and insulated except for the floor which I used 1" styrofoam directly on the cement with a 2"x4" insulated floor sitting on top of that. I took your advice @piratebug and I have a 4" intake coming from my house (basement specifically) to feed heated/cooled air which will be between 18°C/64°F - 20°C/68°F all year. An AC Infinity S4 for intake will be running in tandem with a T6 that is exhausting to keep negative pressure in the space. Garage is fully insulated and dry walled so the temperature isn't quite like outside, a little cooler during the hot days and a little warmer during the cold days, roughly 5-10°C difference in the garage itself. I also have a 1000watt baseboard heater in case I need supplemental heat and this is where I'm back to a lighting choice.

Since I won't be controlling the temperature of the air entering the room from my house my worry with going to a high end LED fixture is that the leaf temperatures will not be high enough if I can't raise the temperature of the incoming air, the cold seeps though in the dead of winter, and my exhaust doesn't allow heat to build up enough. That has led me to CMH lights which would not only raise leaf temps but also give better penetration.

It seems like the heat given off by CMH or LED fixtures will be very similiar if they're both running at the same wattage but it's the UV of the CMH that would help my situation out by raising leaf temps.

So it looks like I have two options:
Use LED and save on electricity but have to supplement heat with the base board heater.
or
Use CMH which isn't quite as efficient but UV present in the spectrum will raise leaf temps so plants will be more happy.

The most recent LED fixtures I've looked at are the Photontek X600 Pro and Migro Aray 4 (times 3). For CMH I've looked at Vivosun 315w and SunSystem 315w but I don't know if 2 will cut it and 4 seems like overkill.

Any help would be appreciated.

I use led and cmh together so you could always try that out. If you need to choose between the 2 I would go with cmh just because your temps will be too cold for Led.

I 2nd the led and CMH run together. I had great luck with it in a 4x4. Not sure I follow why you can't set a thermostat for helping with the heat. Watts are watts with warmth. High power LEDs will generate warmth and if you limit exhaust you should be able to raise the temps. It was easy for me in a not sealed tent.

chronnie49 said:

I use led and cmh together so you could always try that out. If you need to choose between the 2 I would go with cmh just because your temps will be too cold for Led.

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I was thinking I could add two 315w CMH and keep the LED's I have now. There seems to be a few people that do that and have really good results. What are you running for lights?

farmingfisherman said:

I 2nd the led and CMH run together. I had great luck with it in a 4x4. Not sure I follow why you can't set a thermostat for helping with the heat. Watts are watts with warmth. High power LEDs will generate warmth and if you limit exhaust you should be able to raise the temps. It was easy for me in a not sealed tent.

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When I was checking what the best temperatures are for growing I came across some info talking about how with CMH fixtures and the UV present in the spectrum that the leaf temperatures are higher than the air temperature because of the "radiant heating" from the bulb. So even though you could be running 600w watts in LED or CMH the plants themselves would be warmer under CMH. If I have to put power into heating the room so an LED fixture works more effectively I thought it would be better to just put that power into the lights themselves.

What lights were you running?

Squirrel_Master said:

I was thinking I could add two 315w CMH and keep the LED's I have now. There seems to be a few people that do that and have really good results. What are you running for lights?



When I was checking what the best temperatures are for growing I came across some info talking about how with CMH fixtures and the UV present in the spectrum that the leaf temperatures are higher than the air temperature because of the "radiant heating" from the bulb. So even though you could be running 600w watts in LED or CMH the plants themselves would be warmer under CMH. If I have to put power into heating the room so an LED fixture works more effectively I thought it would be better to just put that power into the lights themselves.

What lights were you running?

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I have two 220 watt Alibaba quantum boards and a 315 cmh in a 5x5. I need to buy another cmh before i start flowering then I should be set.

Squirrel_Master said:

I was thinking I could add two 315w CMH and keep the LED's I have now. There seems to be a few people that do that and have really good results. What are you running for lights?



When I was checking what the best temperatures are for growing I came across some info talking about how with CMH fixtures and the UV present in the spectrum that the leaf temperatures are higher than the air temperature because of the "radiant heating" from the bulb. So even though you could be running 600w watts in LED or CMH the plants themselves would be warmer under CMH. If I have to put power into heating the room so an LED fixture works more effectively I thought it would be better to just put that power into the lights themselves.

What lights were you running?

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Sun system boss CMH 3100k and two sf 1000 in a 4x4. New white and red LEDs put out a surprising amount of heat. Adding the CMH really increased the uv. Heat wasn't a issue once I closed my tent down. First indoor grow so more than few lessons learned along the way.

chronnie49 said:

I have two 220 watt Alibaba quantum boards and a 315 cmh in a 5x5. I need to buy another cmh before i start flowering then I should be set.

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I have 2 hlg 260s running over a plant right now that had been outside previously. She's about 6 weeks into flower. Older 3000k boards kick ass can only imagine what hlg's new boards are capable of. Like to run these two with my 315 in my 4x4 again but with them dimmed down either that or buy a 5x5. Actually considered a 4x8 with three of the 260s and 2 315's but I like being married.

I laugh when people bag on LEDs!

Thanks everyone, I'd like your posts but the like button doesn't show up for me for some reason. I like the idea of running CMH and LED and since I have some LED lights already I can just add everything together for now and piece in new stuff as I need to.

There is a Vivosun 315w CMH w/bulb on sale for Prime day that I'm temped by https://www.amazon.ca/VIVOSUN-5-Mode-Adjust-High-Reflectivity-Aluminum-Upgraded/dp/B07RPKT58L/ref=sr_1_5?dchild=1&keywords=philips+cmh&qid=1602299567&sr=8-5 . My gut says it's Vivosun so it's not going to be that great but I'd have Philips Greenpower Agromax 930 bulbs ready to swap in in case I had any issues. Going that way my total cost would be $574.

Otherwise growlights.ca has a Silverstar CMH Vertical https://www.growlights.ca/silverstar-cmh-reflector-315w-ballast-system-w-philips-bulb.html for $349 with the Philips bulb. These are 240V but I've wired so I can go either route. There is a remote ballast version for $380 but integrated seems better for my use to keep the heat.

So $735~ vs $574~. The cheaper option having two sets of bulbs.

I thought these bulbs were better to run base up but if I'm looking at the right specs it doesn't matter https://www.lighting.philips.com/main/prof/conventional-lamps-and-tubes/high-intensity-discharge-lamps/ceramic-metal-halide/mastercolor-cdm-t-elite-med-wattage/928601167131_EU/product

I'm glad I decided to do some more calling around this morning. There is a company in Canada called Commercial Lighting Industries that carries the Philips 3100k 315w for $62.50 plus tax (941 is the same price) as well as a BC Grow Gear Hemlock fixture for $171.xx plus tax. That would be the same cost as the Vivosun bare fixture and I can pick it up local which I like. They're probably both Sinowell rebrands but this will be a good way to get me started and if I have issues I'd rather not deal with Vivosun from what I've read. My first thought was that maybe with the money saved (from what I thought I would have to spend) I should buy a third or one of the Mars Hydro lights on sale on Amazon haha.

Squirrel_Master said:

I'm glad I decided to do some more calling around this morning. There is a company in Canada called Commercial Lighting Industries that carries the Philips 3100k 315w for $62.50 plus tax (941 is the same price) as well as a BC Grow Gear Hemlock fixture for $171.xx plus tax. That would be the same cost as the Vivosun bare fixture and I can pick it up local which I like. They're probably both Sinowell rebrands but this will be a good way to get me started and if I have issues I'd rather not deal with Vivosun from what I've read. My first thought was that maybe with the money saved (from what I thought I would have to spend) I should buy a third or one of the Mars Hydro lights on sale on Amazon haha.

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That sounds like a good deal. I pay €300 for the ballast, reflector and philips bulb.

So you're going to try led and cmh together?

chronnie49 said:

That sounds like a good deal. I pay €300 for the ballast, reflector and philips bulb.

So you're going to try led and cmh together?

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Yeah I'm going to rig up the LED's I have for the back or front of the grow space and then I'll have the 2 CMH fixtures covering the rest of the space. I'm aiming for a 2.5'x2.5' space for each CMH which will have my width covered (5') and then the remaining 1.5'x 4' will be for the LED's. Or I'll have some LED on the front and back, either way.

I'm thinking of rigging something up so that I can move the lights every few days to not keep the LED's is one spot. Like a giant, upside down lazy susan. I'll think on that while I finish everything up. Lighting was the main thing holding me back so now that I have that taken care of I need to move my ass and finish everything else off. I had a section of wall open in case I wanted to run another outlet for 240V but the lights I ordered can be run either 120V or 240V with no benefit either way so I'll stick with 120V. I'm glad I don't have to look for more breakers, COVID is messing with the supply chain and I had to search to find single pole 20A's as it was.