4 1k lights in a 7.5 x 9.5 ft room overkill?

I've been using 1k lights for years, but always on a smaller scale. One per room with 15 plants under each, once I did 2 1000 watters in one room with like 25 plants. I don't do sea of green, these are medium sized plants spaced out so the side branches get some light. 15 good sized plants spaced under 1 1000watt light was good enough to get by, but the outer rows of plants always turned out weak and fluffy. The best performers were always the center 6 plants.. The rooms were a little big for the light and I was trying to fit too many larger plants under one light..

SO I have built a new room that's 7.5 x 9.5 ft. I have four 6" blockbuster vented hoods which are supposed to be ideal for a 4 x 4 ft space.. Do you think 4 1k lights is going to be over kill? I'm still waiting for my electrician friend to stop by and get me all wired up. So I can't test it out with all 4 going yet. These are digital ballasts with digilux bulbs. At the moment I have 2 MH and 2 HSP bulbs in there.

I tried to calculate the lumens per square foot by adding all the lumens up and dividing by the square footage, but I'm not so sure that takes into account multiple lights and the overlapping light from 4 reflectors... I came up with 7719 lumens per square foot. (with my current 2MH and 2HSP bulbs) which falls into the ideal range of 7000-10,000 that I read in the light and lumens sticky.

The reason I'm a little concerned is I just upgraded an old 400 watt coil ballast for my mothers to a new digital 600 watt ballast and the mothers weren't diggin the change. My humidity was down too.. so I ordered a couple humidifiers to eliminate that issue.. in the mean time I'm using the 400 again.. It got me thinking.. are those 4 digital 1000s going to be too much?

Any thoughts?

i think you'll be good , if anything dim them down in the beginning... and focus on insulating the ducts and maybe heat shielding the reflectors , my friend just did these upgrades and it lowered the temp. dramatically... his room is a lil bigger so 12 x 10 good luck

You should be able to have as many as you can cool. The heat will eat up the humidly so keep an eye on that. You may want to buy a big humidifier and put it on it's own res and auto feed. I had to do that with my 4 1000w.

OK so my electrician came by... I ran all 4 with a 440cfm fan pulling through all 4 hoods and a fresh air in pulling in at full power at night with an ourdoor temp of about 43 degrees, I couldn't get the temp under 95-96 degrees in the room!. Was hot and as bright as a nuclear explosion lol.

I already had some of that sunshield ducting (insulated with the shiny silver exterior), however that won't be enough. The hoods themselves still feel pretty cool, most of the heat is just directly under the hoods. It doesn't feel real hot on the back of my hand a couple feet below the hood though.

I don't want to try a max fan because all that air has to be forced through a vent in my roof which isn't even a full 6" hole... I could try two separate can 440cfm fans, each pulling through 2 hoods, instead of 1 fan pulling though all 4 hoods. However I'm not convinced that would be enough, particularly with summer coming soon.

Unfortunately I can't afford the air conditioner I want... so I think I'm going to have to put off my dream of 4 1000's in one room on hold, and just run 2 1000s for the time being. I have been running two in the room and the temp stays at a comfortable 82 degrees.

Thanks for the input guys! You are right about that heat eating the humidity.. dropped from 52% to 20% in no time. Luckily I already have 2 humidifiers on the way I'll also be adding the sunshield ducting and will try the sunshield hood covers.

I would suggest isolating the cooling of the room from the cooling of the lights. if you do not use co2 then use this.

outside of room -> sealed ducting -> air cooled reflector -> sealed ducting -> air cooled reflector -> 440cfm Fan ->exhaust out of room

2 of those for the 4 lights, then you can use a 440cfm fan to through a carbon filter to pull air out of the grow room into the rest of the house or whatever.

This will allow you to cool that many lights. a cheap a/c on craigslist can fix the problem. If you use an A/C don't vent the room, just the lights, then the a/c is cooling only the air in the room, not a constant exchange.

You can try using insulated ducting as well as the reflective heat covers (basically insulation that goes around your water tank heater sticky on one side so that the reflector doesnt act as much like a heater to the room.

That 440cfm for 4000 watts is insufficient, use 1 8" fan ducted to all hoods or 2 6" 450cfm fans (inline fans NOT DUCT BOOSTERS)

hope that helped.

Youre going to have a hard time with the cooling. My room is 7x9 With a 12,000btu window a/c and cant keep the room below 88 with 3200watts. I was running 2 1000 watt light in a row with insulated ducting, air being pulled through with a 440cfm 6" fan. Otherside was 2 600watts w/ insulated ducting and a 400cfm fan. The a/c was constantly on and not keeping the room cool. So today i built a box, hooked up both ducts comming from the lights to the box, then mounted a 440, 400, and 160cfm fan to the box and it still wasnt enough to keep the room cool. So i took one of the 1000 watt lights out and moved the others to be in line.

H -hole
x -600watt
X -1000watt
x -600watt
F -the three fans attached to a box

The temps stay at 79 degrees with the humidity 50-60% sealed room w/co2. Before i sealed the room, a 160 cfm fan pushing fresh air in. Outside temps in the 70's. I had to get a swamp cooler running 24/7 to keep the humidity up. Now i use a Vicks humidifier to keep the humidity good

If you can, get a bigger fan (more cfm)

dudeface said:

I would suggest isolating the cooling of the room from the cooling of the lights. if you do not use co2 then use this.

outside of room -> sealed ducting -> air cooled reflector -> sealed ducting -> air cooled reflector -> 440cfm Fan ->exhaust out of room

2 of those for the 4 lights, then you can use a 440cfm fan to through a carbon filter to pull air out of the grow room into the rest of the house or whatever.

This will allow you to cool that many lights. a cheap a/c on craigslist can fix the problem. If you use an A/C don't vent the room, just the lights, then the a/c is cooling only the air in the room, not a constant exchange.

You can try using insulated ducting as well as the reflective heat covers (basically insulation that goes around your water tank heater sticky on one side so that the reflector doesnt act as much like a heater to the room.

That 440cfm for 4000 watts is insufficient, use 1 8" fan ducted to all hoods or 2 6" 450cfm fans (inline fans NOT DUCT BOOSTERS)

hope that helped.

Click to expand...

Dudeface seems to have it right......1 6in fan is nothing going to do it.....You should upgrade to 8" and get dedicated air cooling

dudeface said:

I would suggest isolating the cooling of the room from the cooling of the lights. if you do not use co2 then use this.

outside of room -> sealed ducting -> air cooled reflector -> sealed ducting -> air cooled reflector -> 440cfm Fan ->exhaust out of room

2 of those for the 4 lights, then you can use a 440cfm fan to through a carbon filter to pull air out of the grow room into the rest of the house or whatever.

This will allow you to cool that many lights. a cheap a/c on craigslist can fix the problem. If you use an A/C don't vent the room, just the lights, then the a/c is cooling only the air in the room, not a constant exchange.

You can try using insulated ducting as well as the reflective heat covers (basically insulation that goes around your water tank heater sticky on one side so that the reflector doesnt act as much like a heater to the room.

That 440cfm for 4000 watts is insufficient, use 1 8" fan ducted to all hoods or 2 6" 450cfm fans (inline fans NOT DUCT BOOSTERS)

hope that helped.

Click to expand...

I was thinking of something like that today. I can't do 8 inch because the vents in my roof are only 6 inches so the air would just have to force though a 6" anyway. I guess maybe you could do that but I like your idea of the 3 separate lines. One for each pair of reflectors and one dedicated to the carbon filter in the room. I took all my hoods down and was re-aranging them for a 2 light set up... I'm gonna hook all 4 back up and give your idea a shot this weekend. I'll need to pick up one more 6" 440cfm can fan..

Thanks for the idea, it seems like my best shot. And obviously the best way to do it if I add an AC unit.

how would you suggest doing this if co2 was being used? and what size fan if you had two rows of two lights with Y connector to fan and Y connector at other end going to filter exhausting lights and room when temps get high

dudeface said:

I would suggest isolating the cooling of the room from the cooling of the lights. if you do not use co2 then use this.

outside of room -> sealed ducting -> air cooled reflector -> sealed ducting -> air cooled reflector -> 440cfm Fan ->exhaust out of room

2 of those for the 4 lights, then you can use a 440cfm fan to through a carbon filter to pull air out of the grow room into the rest of the house or whatever.

This will allow you to cool that many lights. a cheap a/c on craigslist can fix the problem. If you use an A/C don't vent the room, just the lights, then the a/c is cooling only the air in the room, not a constant exchange.

You can try using insulated ducting as well as the reflective heat covers (basically insulation that goes around your water tank heater sticky on one side so that the reflector doesnt act as much like a heater to the room.

That 440cfm for 4000 watts is insufficient, use 1 8" fan ducted to all hoods or 2 6" 450cfm fans (inline fans NOT DUCT BOOSTERS)

hope that helped.

Click to expand...