CFL Efficiency - A Stoner's Challenge

So I got bored at work this morning and decided I would figure out some stats on different watt CFLs. Here is what I have compiled thus far! Any input is welcome.



I am looking to find the specifics of a 10,000 lumen/ft2 grow box. For personal purposes, I am using a 9ft2 area for my own numbers. (The approx. size of what I have available)

I am also using 2 65 watt CFLs as a constant, because again, I have these already available. All stats are from 1000bulbs.com using the cheapest 2700K bulbs in each wattage. Also, assuming the light cycle is 12-12, and electricity is $0.09 per KWH.

SETUP ONE – 42 watt CFLs

2x 65 watt cfl – 4200 lumens each – 933lu/ft2 – Using 1.56 KWH per day
30x 42 watt cfl – 2800 lumens each – 9333lu/ft2 – Using 15.12 KWH per day
TOTAL LUMENS – 10236lu/ft2 – Total of 16.68 KWH per day, or $1.50.

SETUP TWO – 32 Watt CFLs
2x 65 watt cfl – 4200 lumens each – 933lu/ft2 – Using 1.56 KWH per day
40x 32 watt cfls – 2100 lumens each – 9100lu/ft2 – using 15.12 KWH per day
TOTAL LUMENS – 10236lu/ft2 – Total of 16.68 KWH per day, or $1.50.

NOTE : Obviously since the wattage is interchangeable, the main difference is the price per bulb in setup one and two. 42 Watt bulbs were in at $7.35 each, while 32 Watt bulbs were $4.58 each. For the numbers that were being purchased, the 32 watt bulbs were $37.30 less expensive than the 42 watt bulbs.

SETUP THREE – 27 Watt CFLs
2x 65 watt cfl – 4200 lumens each – 933lu/ft2 – Using 1.56 KWH per day
47x 27 Watt cfl – 1750 Lumens each – 9139lu/ft2 – Using 15.228 KWH per day
TOTAL LUMENS – 10072Lu/ft2 – Total of 16.788 KWH per day, or $1.51.

SETUP FOUR – 23 Watt cfls
2x 65 watt cfl – 4200 lumens each – 933lu/ft2 – Using 1.56 KWH per day
51x 23 watt cfl – 1600 lumens each – 9066.7lu/ft2 – Using 14.076 KWH per day
TOTAL LUMENS – 9999.7Lu/ft2 – Total of 16.636 KWH per day, or $1.41.


What did I learn from this seemingly pointless research?
Well, a few things. First, it showed me that I more than likely cannot reach the desired threshold of 10,000 lumens per square foot in an area the size of what I have available. Packing even 30 bulbs in to a space that is 2.3 x 2.18 x 1.8 just isn’t reasonable. I think my next step will be going through completed cfl grows, and comparing yield with lumens per square foot. I’m sure with enough data then a new threshold can be established. I understand that 10,000 is ideal, but it simply isn’t reasonable in a small space. If this is simply aimless rambling, feel free to flame on me, I love a good roast. Cheers!

You started out saying 10k for 2 sq ft not one. That I think is doable. I don't think I'd put 10k/sqft on vegging plants if it was offered to me for free. I think you really can have too much light and 10k is what the sun puts on the earth's surface. No plant in nature gets that 24/7 week after week.

Illegal Smile said:

You started out saying 10k for 2 sq ft not one. That I think is doable. I don't think I'd put 10k/sqft on vegging plants if it was offered to me for free. I think you really can have too much light and 10k is what the sun puts on the earth's surface. No plant in nature gets that 24/7 week after week.

Click to expand...

Thanks for the reply! A couple things I was prolly pretty unclear about.

The sun puts out 10K lumens per square foot. That is the *ideal* amount, if by ideal you mean emulating nature while removing all possable flaws and hinderances. I abbreviated lu/ft2 because I was to lazy to use a superscript for the 2... I think that is where you got 2 feet. The measurement that I am seeking is 10,000 Lumens per square foot of space in the grow room.

IE. A 2'x2'x2' grow room has 8 square feet of space available. You're goal is to have 80000 lumens in that space, allowing 10,000 lumens per foot of grow space.

Now. Another key part of this, is this it is for the *Flowering* "Chamber". Plants only need about 3000 Lumens per square foot in order to achieve proper veg growth, so you are right in saying it would be silly to apply that much light to a veg room.

As for having 10K flowering, your plant is now mature, and seeking the most efficient way to grow without restriction. In such a small grow box, you want to limit as few variables as possable. Since I grow in 16 ounce cups from Veg to harvest, I know that my root structure is going to be challenged from the get go. I have also seen a 2 oz plant in only a 16 oz dixie cup, so roots arn't the end all say all.

I am new to growing, and have learned almost everything right here on RIU. My first plants were horrid, and I actually just tore them down in the last 48 hours. I hate failing at anything, expecially something I have become so passionate about... So I am doing everything possable to produce the best possable girls with what I have available to me.



Peace and love

like i previously ima pull a seat up to this i want to see you actually go for it and throw some pics up. with all this math and electrical light crap i hope to see a bad ass grow soon! lmao ima subscribe fo sho! lol happy growin lata bro Smoke One! =)

I think it is very questionable how ideal 10k lumens is. Nature doesn't provide sunny days day after day. All I know is people consistently get a dry half pound out of a 2 sq ft space and 3 or 4 plants using no more than 300-400 watts of cfls total.

hold it...math error...a 2'x2'x2' room has 4 square feet of space...and 8 CUBIC feet of space...but nice job on doing all the rest of the work...

So I have been quite busy the last week or so, trying to make micro changes on the fly.

like i previously ima pull a seat up to this i want to see you actually go for it and throw some pics up. with all this math and electrical light crap i hope to see a bad ass grow soon! lmao ima subscribe fo sho! lol happy growin lata bro Smoke One! =)

Click to expand...

Thanks for dropping in! I am gonna be constantly changing things as money allows. 60 days seems alot shorter amount of time since I started growing. When you think about watering, light cycles, growth, nutrients, and everything else, you can let time slip away! It seems to me like I changed my setup yesterday, but it's already been a week! I am gonna add the pictures from the changing setups over the last few months.

I think it is very questionable how ideal 10k lumens is. Nature doesn't provide sunny days day after day. All I know is people consistently get a dry half pound out of a 2 sq ft space and 3 or 4 plants using no more than 300-400 watts of cfls total.

Click to expand...

I completly agree! I used 10K as a goal, simply because I know that is what works in nature. I am 100% planning on changing the goal, as I accumulate more evidence and proof via cfl grow logs. If you have links to any, please please please hook me up! A dry half pound with cfls out of 2 sq ft space? Sounds amazing! Hook me up bro!

hold it...math error...a 2'x2'x2' room has 4 square feet of space...and 8 CUBIC feet of space...but nice job on doing all the rest of the work...

Click to expand...

Thanks for dropping in! The dimensions are not, in fact, 2x2x2 in my room. They are 2.3x2.18x1.8, giving me 8.942 square feet. I rounded this to 9, and that is what I did my numbers based on!

I did give the example of a 2x2x2 room, but I also said it would have 8 square feet if that were the case. Look at my second post!

I mentioned I would put the changes I have made in! So here they are.

The first plants ended with 2 females, both being harvested after 6 weeks because they were not growing. About 5 or 6 grams dry.

Don't forget about the ct. under 3000k for flower and over 5000k for veg. sorry if you had that in there and I missed it.

dude SHIT!!!! thats alot of changes made but thats kinda how i am (like in journal) on a paycheck to paycheck basis seeing what i can upgrade to lol!! or at least for me.. looks like youv had some grow experiance? seems like it. anyways the girls all look very good in all pics! were those at various times in growth with your plants?? like a few flowering or is this all veg setups? oh and i did a big change in grow i will post tomorrow in the evening round same time as this post. oh and the uhhh forget it im high nice shit bro! will stay tuned! Smoke One!!!

livelife8345 said:

dude SHIT!!!! thats alot of changes made but thats kinda how i am (like in journal) on a paycheck to paycheck basis seeing what i can upgrade to lol!! or at least for me.. looks like youv had some grow experiance? seems like it. anyways the girls all look very good in all pics! were those at various times in growth with your plants?? like a few flowering or is this all veg setups? oh and i did a big change in grow i will post tomorrow in the evening round same time as this post. oh and the uhhh forget it im high nice shit bro! will stay tuned! Smoke One!!!

Click to expand...

Thanks for droppin in! Those pictures are from the "original" setup, when I thought 5 23 watters would be fine for my whole closet! Hahaha. Now the rubbermade is a veg box, and the closed off closet is a flowering box! =-)

Don't forget about the ct. under 3000k for flower and over 5000k for veg. sorry if you had that in there and I missed it.

Click to expand...

Hey Stumps! Thanks for comin' by! Are you talking about the 3000 and 5000k bulbs? If so, I can definately get the numbers for them as well if it is something you are interested in! Just lemme know!

thats funny as shit!! lmao umm im doing same exact thing except the cab/snake tank is my veg and closet for flowering actually getting a hps for the closet for optimal flowering!! thats the change that i was doin but i already did it feel free to take a look at the journal day 22 well im fucking blazed and ready to DIE!! lol nite! Smoke One!! lol again..

Topher89 said:

I did give the example of a 2x2x2 room, but I also said it would have 8 square feet if that were the case. Look at my second post!

Click to expand...

minor point, but when you use three dimensions (length, width and height), you are calculating volume, therefore CUBIC feet...when you use two dimensions (length and width) you are calculating area, therefore SQUARE feet...thats all...no biggie...peace

Although 10,000 lumens per square foot is desirable it will not be achieved with 42 watt cfls. The fact is lumens do not add. So if you have four 42 watt cfls in a square foot you could add the lumens and say i have around 12k in the square foot but thats not true due to lumens not adding, you'll only have 2700 lumens with better light coverage.

One thing I can say for experience hps light pack on more weight, less lights to hang, produce a lot of heat and are cheaper.

more weight is best, after all isn't that why we grow?
less lights to hang is awesome, I use to hate hanging several aggervating lights.
heat is an issue but with an ac or air cooled light heat is no problem.
believe it or not hps lights are cheaper or same as clfs. last i checked 42 waters are around 7-8 bucks and the fixtures 5-10. a 400 watt hps is $120.

Yes, overdue the lights and then no reflectors which reflect and add quite a bit of light. I bet it can be done wih just three Bulbs. 1) 42w cfl, 1) 23w cfl, 1)UVB 2.0 23 w cfl. This over 14 seedlings, then narrow down to about ten make it to sexing, then you get your best three females. and walla for 25 cents a day in power you got bud. Not much but about a half o a plant if you let it go full. Oh yea and the UVB is amaizing for crystals.

So thats 88 total watts (VEG 88.18.14=22176, 22.176 kw) or $2.22, peak probly so $4.00 High est.

Then flower 88 wats again, no bulb change! but 12 hrs and more days so we say 80 days (FLR 88.12.80=84480. 84.5 Kw or $8.45, peak probly $15.00 High est.

So no fans, no bublers, no bs, just mixed dirt...compost at that. Of course if the power companies wouldn't charge so much BS on the bills, and serv. charges, etc.

I figure if you have a good reflector you can grow about and once and a half with three plants under this setup for under 20 bucks over 3 and a half months.

I have seen some setups that do nothing but waste light. I think there is suck a thing as too much light, especially if its to far or misplaced, may as well not be there. I had a "fire hazarad" set up for a while. Then i turned off half the light and they DID BETTER! Temp better, spectrum is important!

arcticvapors said:

minor point, but when you use three dimensions (length, width and height), you are calculating volume, therefore CUBIC feet...when you use two dimensions (length and width) you are calculating area, therefore SQUARE feet...thats all...no biggie...peace

Click to expand...

You know, you are completly correct. It seemed sensable to include the height into the equation, simply because You could have a 1 foot room, and a 100 foot room, which is still two feet by 2 feet if you only measure the length times the width. Perhaps I am completly confused?

Because of this, I judged my number on 9 ft square, as opposed to 5! I am going to rerun my numbers on my individual size room, and get the info out here. of course, the previous numbers would still be correct if you are using a 3x3 grow room... They simply don't apply to my room.

HarvestFest2010 said:

Yes, overdue the lights and then no reflectors which reflect and add quite a bit of light. I bet it can be done wih just three Bulbs. 1) 42w cfl, 1) 23w cfl, 1)UVB 2.0 23 w cfl. This over 14 seedlings, then narrow down to about ten make it to sexing, then you get your best three females. and walla for 25 cents a day in power you got bud. Not much but about a half o a plant if you let it go full. Oh yea and the UVB is amaizing for crystals.

So thats 88 total watts (VEG 88.18.14=22176, 22.176 kw) or $2.22, peak probly so $4.00 High est.

Then flower 88 wats again, no bulb change! but 12 hrs and more days so we say 80 days (FLR 88.12.80=84480. 84.5 Kw or $8.45, peak probly $15.00 High est.

So no fans, no bublers, no bs, just mixed dirt...compost at that. Of course if the power companies wouldn't charge so much BS on the bills, and serv. charges, etc.

I figure if you have a good reflector you can grow about and once and a half with three plants under this setup for under 20 bucks over 3 and a half months.

I have seen some setups that do nothing but waste light. I think there is suck a thing as too much light, especially if its to far or misplaced, may as well not be there. I had a "fire hazarad" set up for a while. Then i turned off half the light and they DID BETTER! Temp better, spectrum is important!

Click to expand...

This completly sounds like in the right circumstances, it could work! What i wanna see is a journal detailing, and SHOWING it happen. I am trying to get as much physical proof as possable. I believe that the goal is much, much lower than 10,000 lumens, but I want to gather evidence that supports it!

gardenman said:

Although 10,000 lumens per square foot is desirable it will not be achieved with 42 watt cfls. The fact is lumens do not add. So if you have four 42 watt cfls in a square foot you could add the lumens and say i have around 12k in the square foot but thats not true due to lumens not adding, you'll only have 2700 lumens with better light coverage.
heat is an issue but with an ac or air cooled light heat is no problem.
believe it or not hps lights are cheaper or same as clfs. last i checked 42 waters are around 7-8 bucks and the fixtures 5-10. a 400 watt hps is $120.

Click to expand...

When I agree with you, I also disagree with you. Because of my grow space and location, I *need* to use CFL for a multitude of reasons. While I am completly open to using HID lighting, and it has MUCH documented success, CFLs simply make more sense. Not to mention with an HPS I would still use daylight CFLs for supplimental lighting!


I am now doing a bunch of research, and will come back with examples of what I find. This is exactly what I wanted from RIU users. Thanks again!

ALRIGHT. I have it all now.



Let’s start by looking at THIS.



This is going to lay the ground work to understanding the lighting problems! Our CFL bulbs are the center of the meter circle.

Now, one LUX is one Lumen per square meter. It is simply an abbreviation. When we speak American measurements, we go with a Foot-candle!
Obviously, LUX is based on the distance of one meter, and Foot-candle is based on the distance of one foot, or 12 inches.

So we are not seeking the AMOUNT of lumens, we are measuring the amount of FOOT CANDLES that we want! Lumens is the intensity, and FOOT CANDLES are the amount. If you with to use the MAXIMUM AMOUNT OF LIGHT A PLANT CAN USE, then you seek 10,000 FOOT CANDLES in Flowering, 2500 FOOT CANDLES in Veg, and only about 375 in clone/seedling stages.

Now. You have to find out your space, and allow for that many foot candles! So a 5 square foot space will have 50,000 foot candles. You can ALWAYS increase the AMOUNT of light.

If you wish to speak LUMENS closer than one foot from your source, then you simply use Candlepower! 12.57 LUMENS is ONE Candlepower! Candlepower is a rating of light output at the source, using English measurements. So for every 12.57 LUMENS, there is ONE candle power. It would make things much more convenient if they included the Candlepower of their lights on the packaging, because then through the Inverse Square Law we could find the amount of lumens being projected at any one point away from the light. They only give Initial Lumen Output, but again, we can divide that by 12.57 to find our Candlepower.
.

Now, all of this is a big work around because the definitions use each other to explain… Interesting, huh?

If you have a light bulb that is putting out 4500 lumens, then it is also putting out 4500 foot candles, because the light could be “constricted” into 4500 one lumen columns. You change the amount, but increase the intensity.

All in all, you want to have 10,000 for flower, 2500 for veg and 375 lumens per square foot for seedlings. People are right in saying that lumens do not add together, but the amount of light is what we need to add. You can achieve an ILLUMINANCE level of 10,000 foot-candles, or 107,500 lux, with either one large bulb or many, many smaller bulbs. This is definitive. So if your plants are within a foot of your bulbs, then you will be putting out the lumen output. You get more lumens the closer you go, and that is necessary because it’s very hard to get enough light bulbs into the grow space to get 10,000 foot candles! You need to go smaller scale, and achieve better results by placing the plants as close to the bulbs as you can without heat hurting the plants.

People are misusing Lumens, when they wish to speak of foot candles. This is because for what concerns us, 1 lumen = 1 foot candle, so they *can* be used interchangeably…. But if you wanna get technical, they are different things altogether.

So that about wraps it up. I got my information from a bunch of sources, including Jorge Cervantes Marijuana Horticulture Bible Page 172. As well as the following websites.
http://www.theledlight.com/lumens.html

http://www.candlepowerforums.com/vb/showthread.php?t=174000

http://docs.google.com/gview?a=v&q=cache:z-a3SbNXP2MJ:www.energymanagertraining.com/energy_audit_instruments/lux_meters/pdf/light%20measurement.pdf+lumen+intensity&hl=en&gl=us

http://www.energybooks.com/


I hope to Christ this puts a stop to all this jabber, and starts bringing in people showing me how many foot candles produced how much dry herb!
BRING THE JOURNAL LINKS!

LET THE GAMES BEGIN..

ok...now my eyes are completely glazed over...and i haven't even smoked yet!