420 Magazine Background

Too many CFL's?

theapprentice

New Member
Hello all. This is such a great site. I have been reading for a few weeks just trying to wrap my head around all this great info. I am planning a single plant scrog for my first time in soil. I am going to make a cabinet with finished inside dimensions of 20"x20"x4' tall. If you factor the 2 inches lost all the way around for the pvc frame to hold the screen then my potential plant sqft is 16x16. Using the info i have learned here i need 10.08 lights to make 10000 lumens. This is factored using the 26watt lights i bought. My pvc ballast plans allow me to fit all 10 lights horizantal to the growing screen. So to start my many questions to come, is this to much light? Not enough space for a scrog? I want to maxamize my yield since its one plant. I could make the space larger but i dont want to if it compromises results. I really dont want to run more then 10 lights. Guess im just looking for some comfermation before i invest the time and money into this cab and grow. If two plants with slightly bigger cab would produce better results only adding one light then i may adjust. Thanks in advance to any and all advice
 

GrowGSL

New Member
Hey Man, Maybe I can give ya a hand. You defiantly go the right idea for a Small grow setup, using scrog is the way to go. I'm thinking for your setup 1 plant can fill that area fine and just simplify things for you.


you got a 20"x 20" Id say you can count the whole thing not just 16x16. Just allow your plants to grow just a bit over the screen framing. Anyhow the 10 CFL thing, I can give your and educated guess, this will be REALLY hot. what kind of ventilation you plan on running?

Is sound an issue, cause the fans you will need to cool are going to be a bit loud.

Just let me know you questions I'll help ANYONE!
 

theapprentice

New Member
Sound is not really an issue. I have to put the box in the attick. I plan on cutting a hole in the ceiling and adding another hvac grate. Duct that straight into the box with a fan in the bottom of the box pulling the air in and blowing it up threw the box. I will put another fan at the top that exits to a charcoal filter. The next question i have is about heat. My attick gets very hot in the summer. Easily over 100 with very high humidity( i live in the south). With pulling that fresh ac air in and sealing the box completely, does anyone see an issue with the heat outside the box? I know i will need to insulate the box, planning on foam for the outside.
 

GrowGSL

New Member
Sounds like your airflow will be good enough, your pulling air from inside the air conditioned house?
 

theapprentice

New Member
Was thinking it would be cheaper then a seperate unit. Dont think it spike my electric bill to bad but i dont know? Any other suggestions?
 

GrowGSL

New Member
well Actually I don't think it will spike the electric to much using current air from home, it's a great idea, however adding a separate AC unit would add A big cost per month for the little amount of buds those 10 cfls will produce for you.

They are going to be hot thats alot of cfl. Attic grows are tough period in hot areas.
 

theapprentice

New Member
I am worried about the heat. Would be easier in the house. I am going to get the box done, mount the light and see how the temps do. Have a digital thermometer for inside and shows outside temps to. It will record min. Max temps for the day and I will monitor everything before i put plants in. If I cant control the temp then I will have to change locations. I am trying to keep it out of the house but if it doesnt work then I have no choice. Thanks for the advice so far friend. Much appreciated.
 

theapprentice

New Member
I will. Wish i could afford to go led. Just not in the budget right now. I figure i will always be able to use the ballist i am making now. It will be out of pvc. Have a row of four bulbs facing another row of four. It will be made to have two more bulbs(one coming from each side) in the middle. I am debating going with two more bulbs from the middle and make the cab a little bigger for two plants. Ah decissions...
 

HiTech-Hate

New Member
You can pretty much never have 'too' much lighting, but you can have too much heat.

I'm currently growing using 10 (23W) CFLs myself, here's a link to a thread with some pics of the fixture i made:
http://www.420magazine.com/forums/grow-lighting/146758-pics-10-lamp-pvc-cfl-light-fixture.html

I have had heat troubles since day one. When I put 260CFM high static pressure exhaust I was able to keep it at 75F .. until I installed the carbon filter on the exhaust fans, and now i'm at 85F and don't really know what i'm gonna do about it.

My grow space is fairly close to yours at 18"x30"x3.5'. I also live in a very cold basement 60-65F, so we're talking an increase of 20F, CFLs can no question put out heat.

Also, your lumens calculation is no hard and fast rule. Its great you took the time to be quantitative about it, but truth is. no one has the authority to say 'you should have this many lumens per cubic foot', there are far too many other variables involved to make it that simple. Eg. PAR output, strain, and its respective response to light, as i'm sure some respond just as well to fewer lumens then others, reflectivity in the cab, etc.).

Anyways, i'm just throwing it out there, with my 10 CHEAP (23W) CFLs I have been hitting my head against the wall from day one trying to figure out how to dissipate heat.

I just bought a package of lamp wire from lowes. I'm pretty sure its 14 gauge, but 14 or 16 shouldn't matter, 23W CFLs aren't pulling a whole lot of current through them anyways. Remember to wire your lamps in parallel !
 

GrowGSL

New Member
houses are wired at 12 gauge, if you keep your wire thicker than that you will be safer because the breaker will flip before the wire melts if theres a problem.
 
Top Bottom