Do you vent every light, or the room as a whole?

Seeing some of those hoods with 2 ports for cooling and exhaust makes me wonder how those growers vent multiple hoods without tons of tubing and multiple exhaust ports in their room.

Is is ok to just vent the whole room? I know this would mean getting rid of a lot more air, but on the plus side that will bring in fresh CO2. Also the light setup can be much simpler (wing reflector and no hood) I figure a couple of oscillating fans strategically placed on 2 adjacent corners can help push the air towards the driection of the exhaust.

It's only necessary to go with those lights that vent if you have heat issues with your light.
But having a light thats not vented keeps the grow room heated.
It comes in handy, especially when the temps outside are below freezing.

I'd only get one if your thinking about get a 1000 watter.
Personally I think growing with 1000 watters is a waste of money and energy.

You can grow way more plants with no heat issues with two 600 watters than with one 1000 watter.

BongJuice said:

It's only necessary to go with those lights that vent if you have heat issues with your light.
But having a light thats not vented keeps the grow room heated.
It comes in handy, especially when the temps outside are below freezing.

I'd only get one if your thinking about get a 1000 watter.
Personally I think growing with 1000 watters is a waste of money and energy.

You can grow way more plants with no heat issues with two 600 watters than with one 1000 watter.

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I find it hard to believe that 1200w is easier to cool than 1000w
Of course you can grow more plants with two 600's, you are using 200w more light
Care to elaborate on the heat deal?

I've set a few rooms up using a large carbon filter 10-12" ducting and splitting into two runs of 6" ducting and back into a 12" for exhaust.

A 12" fan will cool 6-8 1KW lights no problem

tom__420 said:

I find it hard to believe that 1200w is easier to cool than 1000w
Of course you can grow more plants with two 600's, you are using 200w more light
Care to elaborate on the heat deal?

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So your able to subtract a 1000 from 1200.

A 1000 watt bulb has to be further away from the tops of the plants than a 600.
Which would only make sense to buy a cool tube light if wanting to grow with a 1000 watter.
A 600 watt bulb doesn't create as much heat and can be closer to the plants than a 1000 watter.
Two 600 watters can cover a much larger growing area than one 1000 watter.
Thus meaning, you can grow alot more plants.
One 1000 watter, you can grow about 8 - 4 foot plants
Two 600 watters you would be able to grow 12 - 4 foot plants.

A 600w bulb doesn't create as much heat as a 1000w, but two 600w HPS will
You never answered how 1200w HPS runs cooler than 1000w HPS, or rather would have no heat issues as you put it
How is a 1000w going to give you heat issues but two 600's will not?

tom__420 said:

How is a 1000w going to give you heat issues but two 600's will not?

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I take it your assuming that my theory is both 600 watt bulbs are sitting next to one another.

I have a very large grow room.
So when I give off my theories, I think of my grow room.

BongJuice said:

I take it your assuming that my theory is both 600 watt bulbs are sitting next to one another.

I have a very large grow room.
So when I give off my theories, I think of my grow room.

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this makes sence to me. he is right you can have the 600 watts closer than the 1000 watts because each 600 watt light gives off less heat than the single 1000 watt bulb but when it comes to heat issues in the room temps all depends on an individuals grow room

. . ive got to say if heat isnt an issue, like for myself, northpole status, that side by side(1kers) they blow 600's away. dont care wut any1 claims, i have 2 600's right between 5 1kers, and the buds are always smaller under the 1200 w canopy. there it is

oh and for the orginal question, a good setup for mulitple lights would posslibly encompass venting the lights with sealed hoods, and a exhaust fan running inline when lights are on. (exhausting only lights) and another exhaust fan exhausting the entire room on a thermostat, with a passive hole to suck fresh air from...

A common misconception. The limit is not set by plant count, with all things equal, it is the watt per sqft. I am getting the same yield with 3 patients (18 in flower) as I was with 5 (30 in flower). If you train and supercrop a plant I get the same yield with 1 plant under a hood (600 or 1000) as I did with 4. I would never do more than 4 under a 1000 unless it was a SOG. People think "well if I got 4 lbs off of 10 plants then I'll get 8 lbs off of 20. Wrong thinking. Once you have optimized all other aspects (ie 7 gallon air pots, proper co2, etc) it comes down to more watts more yield. The advantage of 1000 watt cooled is greater depth of the lumens, meaning the effective light reaches further down in the canopy, translating into more useful bud and less scuff (hash scraps). I have a lot of pics but I'm still sketched to post em. I've lurked in these forums for years and just now started getting the balls to post. Having just survived divorce court with my angry ex telling the judge and court room EVERYTHING and the judge turning around and reprimanding her has givin me a little more confidence in my legality. So I'm slowly coming out of the closet or basement actually. hehe. But on the real go with cooling 1000watt. I have replaced all of my 600 which was a waste of money but a learning process. Any pro will tell you it comes down to watt (or really lumen) per sqft. I keep my 1000 watters about a ft from the canopy and use 4 hoods per 8" fan all in a straight line with hard ducting along except where they have to move only. Air turbulence will via bends, square hoods, and even the ridges in flex ducting hamper the airflow. All my new hoods are the reflective hoods with the cool tube in em for this reason. I love the light spread from the xxxl magnums but the eficiency of the the tubes (no turbulance) far outways the minor spread. As a result I can run 6 1000 watters on one 8" fan vs 2 600 watt and 2 1000 watt on my previous. I was running out of holes to vent out and sick of dropping the dimes on inline fans and was able to get another ballast and bulb instead of another fan.
Hope this helps.