Help with new flowering room setup--HID lighting

Hi everyone. Thanks for looking. Sorry for the long winded post here, I just want to be as detailed as possible.

I used to grow exclusively in a very small cabinet I made years ago. It is pretty much 2x4 feet with about 7ft of head room. Ventilated with a small inline fan cooling a 400w HPS fixture. I only wanted to outline this to let everyone know what I AM familiar with. Lol. I am not familiar with larger setups, or higher wattage lights, which brings me to the focus of this query....my lights.

I am in the process of completing a new flowering chamber that has been converted from my root cellar. It stays dry and the ambient temp is pretty much the same as the rest of my basement and current grow space. Really it is just a concrete room in the corner of my basement. It does get a bit warmer or cooler than the rest of the basement simply because the ceiling is my front porch slab/floor. Right now in July heat it is about 70-75°F and 55% RH. Mind you this is in its stagnant state with no circulation. Only the door left open. I plan to ventilate this space well and even have a dehumidifier if needed. It stays much cooler in general when it is not so hot outside. Right now it's been in the upper 80s to low 90s outside.

The room is 9X5.5 feet with 7ft headroom. My plan was to space 3x 600w air cooled HPS hoods equidistant from each other with 16" from the wall on either side. I can draw a diagram later if anyone feels it necessary.

I already have purchased all the lights and mounted them, so please don't suggest I use LED instead or anything like that. It's not that I am opposed to that, but I already spent the coin and did the work. Hindsight is 20/20. I am old school, I like old school tech, and the shit was cheap. I am aware that LED may have been a better choice but among the listed reasons above I also am totally unfamiliar with LED lighting.

I plan to cool these units totally inline with each other using a CanFan Max 8" H.O fan. It pushes 930cfm at max setting but even on low moves a ton of air. I plan to exhaust this either outside as there is a vent to outdoor right there in the room, but also am toying with blowing it out to the other side of my basement. During the hot season the air in that side of the room is about 65 degrees and even cooler in the winter. I don't mind blowing it outside in the summer, but in the winter I am afraid it will cause ice issues on my porch and make a ton of unwanted noise in general.

So anyway after all the details here I am now wondering, nervously I might add, if anyone thinks this is way too much heat/light/wattage for this small a room? I tend to go overboard with things and jump in before thinking it out entirely. I really thought initially that this would all be totally appropriate but am now just concerned about all the heat. What do y'all think? Any advice or input is greatly appreciated! Thanks again for reading.

TLDR: is 3x 600w HPS going to be too hot for a 9x5.5 foot room?

I could also go 2x 600w HPS and a 400w MH in the center for additional blue spectrum and a bit less heat. Just a thought.

I've also included pictures of the setup as well as my old cabinet which I have never had any heat or humidity problems in. Food for thought.

If you have all the gear why havent you tried it out yet? Seems like the best way to get a baseline.
LED? Just cause you got those 600s doesnt mean you can't mix lighting. Try it out, now would be the best time to see if its too hot, and if you feel its too hard to manage then wait a couple of months for the worst heat to go away and then run hps thru winter. Then next summer get a few led lights that have a formfactor making it easy drop in somewhere, maybe in between two hps on the ends; maybe two leds flanking your centre hps. Its not an either or game, you can grow with leds and hid side by side. Its easier though if you have the lights mixed.

If youre testing out your system make sure you also factor in transpiring plants; they will drop temps somewhat. But if youre going to need a dehuey all bets are off they add quite a lot of heat.

Nice setup and yeah the price on HID's are hard to beat I get it. You could put the middle one on a timer if you needed to control heat, and say run the middle one for just 4 hrs like a mid day sun would do.

If you’ve got the amperage and enough air conditioning it’ll work. If you’re cash cropping, even in non legal states there’s not really enough money in it anymore to justify the running costs when anyone can go online and order $100 ounces in the mail

New to the forum; I think you will end up ventilating to the outside. Some factors to consider are that humid air absorbs temperature better than dry air, the radiant heat from the IR produced from these means the leaf surface temperature will be higher than air measurements, and that having extra headroom between your lights and your crops allows for air to move temperature and humidity away from the leaf surface. I haven't owned HID lighting and have never used it in a small space, but you should consider mounting them directly to your wood post rafter since you plan to use this for flower only. If you find after venting to outside that your humidity is on the low end of acceptable while temperatures remain high, you may benefit from evaporative cooling, but this is dangerous to use without a probe measuring humidity that can turn off the machine. Stirring that humid air before venting within the space improves the efficiency of that system.

Ideal coverage for a 600 hps is 3x3 or slightly over.
So your well lit .
I wouldn't use less unless summer beats you.

There's two options.

One using the big fan and isolating the hoods so you draw air from outside, straight through all hoods , straight outside.
Then a separate fan and filter for air exchange and smell control in the actual grow, using cool basement air and sending I outside.

Or , you use one fan to do it all. I'd suggest that in winter. If you can do it in summer is a case of trail and error.

Because your temps are stagnant readings right now. You won't know until you get the airflow moving and lights on.

Obviously you'll run lights off in the hottest part of the day.

I ended up removing the center light for the time being. I have one extractor fan pulling the air out and exhaust into the lung room. I know this is not ideal and is only temporary while I build my vent box outside.

Currently the temps are within acceptable limits and I don't mind the reduced footprint. I like having the space between the walls to move about and care for each plant individually. I figure I can run 4 plants under each light the size I like for a total of eight. Perfect for me I think!

Temps with both lights on are about 80-82°F and one light on stays below 77°. RH is between 45 and 58 depending on if I have the AC running or not. The whole basement is air conditioned so that helps.

coreywebster said:

There's two options.

One using the big fan and isolating the hoods so you draw air from outside, straight through all hoods , straight outside.
Then a separate fan and filter for air exchange and smell control in the actual grow, using cool basement air and sending I outside.

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I have toyed with this idea of drawing outside air to cool the lights and looping it right back outside. Although I think this would work during the hot and the temperate months, during the winter I would fear rupturing the bulbs or simply creating a ton of condensate everywhere with the dry and frigid winter air. I do like this idea in theory though so if your opinion differs I would love to hear it!

Mr.Chabs said:

I have toyed with this idea of drawing outside air to cool the lights and looping it right back outside. Although I think this would work during the hot and the temperate months, during the winter I would fear rupturing the bulbs or simply creating a ton of condensate everywhere with the dry and frigid winter air. I do like this idea in theory though so if your opinion differs I would love to hear it!

Click to expand...

You just adapt it for winter so you use filter>fan>hood>hood>hood> out

coreywebster said:

You just adapt it for winter so you use filter>fan>hood>hood>hood> out

Click to expand...

Aye makes sense bud sounds like a plan

Mr.Chabs said:

I have toyed with this idea of drawing outside air to cool the lights and looping it right back outside. Although I think this would work during the hot and the temperate months, during the winter I would fear rupturing the bulbs or simply creating a ton of condensate everywhere with the dry and frigid winter air. I do like this idea in theory though so if your opinion differs I would love to hear it!

Click to expand...

I did this at my old house and invited some pests in. I live in pacific nw though