Watts/lumens per square foot ?

[LexLuthor]

I didn't want to get off thread topic but for whatever the reason someone is driven to look at alternative grow lighting this is why I brought it up here. And ttystikk statement reiterates the 'big picture' perspective I had only attempted to illustrate.

The 4th amendment is being whittled away on a daily basis. One cannot expect privacy and due process to protect us in our daily habits and routines.

http://en.wikipedia.org/wiki/Fourth_Amendment_to_the_United_States_Constitution

I might further add to ttystikk comments relative to this thread is that we live in a world where;

Big Brother looks to the hydro shops to provide them with a list of customers buying a lot of replacement high wattage HID lamps.

The wireless companies freely hand over cell records to any law enforcement agent who simply asks for them.

From an economic perspective; total consumption has always been an important element in determining total cost/m2. From a shifting political/enforcement perspective, consumption based on unusual patterns which I believe to be from a variety of sources to be in excess of 50kw-hrs/day, continuous patterns, should be taken seriously. In the interest of combining these two perspectives I would propose the importance of watts/lumens is of less significance to a grower than a Watts/DLI measurement would be.

5 ea., 1000 watt HID lamps @ 12 hrs/day = 60kw-hrs/day less any AC or ventilation loads not to mention the rest of the property.

This Watts/DLI can get into some complex, but straight math that takes lamp efficiencies into consideration. Before others on here jump my ass I'll be the first to agree that neither a Watts/DLI nor a Watts/Lumen equation takes into account the plants photobiological responses to specific spectrum's being emitted by their beloved HID lamps which are weighted to either vegetative or flowering activities.

just sayin...

Thats cool, you can say what you want, no problems with me. I just don't understand why ttystikk, in this thread and a couple others, starts talking shit to me. Lets take this thread for example, I said "your joking......right????" then ttystikk said "blah blah blah, think before you shoot off at the fingertips with me-kid, its pretty clear you think you know alot more then you actually do". So I asked him a question and he tried to start an argument with me for no reason, thats all I gotta say bout it.

 

[El Cerebro]

Thats cool, you can say what you want, no problems with me. I just don't understand why ttystikk, in this thread and a couple others, starts talking shit to me. Lets take this thread for example, I said "your joking......right????" then ttystikk said "blah blah blah, think before you shoot off at the fingertips with me-kid, its pretty clear you think you know alot more then you actually do". So I asked him a question and he tried to start an argument with me for no reason, thats all I gotta say bout it.

Because this is what happens when some guy (Chazbolin) constantly comes into various forum threads shilling for Indagro, tying to hijack community discussions for selling products from a non-Farm approved vendor.

 

[chazbolin]

lumens are for humans

The main difference between a photometer (measuring lumens) and a PAR meter is that the PAR meter does not adjust it’s readings for the spectral sensitivity (the luminosity function) of human visual perception of brightness.

 

[ttystikk]

lumens are for humans

The main difference between a photometer (measuring lumens) and a PAR meter is that the PAR meter does not adjust it’s readings for the spectral sensitivity (the luminosity function) of human visual perception of brightness.

And this is exactly why I'm saving my pennies for a good quality quantum meter.

 

[chazbolin]

excellent! then we can all join your Watts/DLI forum

 

[Crysmatic]

I just picked up a Gavita Pro 1000 DE. Whazzup (on an international forum) recommends 1000 umol/m²s, and 1500 max given a perfect environment and CO2. Hung 24" above the canopy, it will light a 48" x 65" area (it casts a rectangular footprint with a 1:1.35 aspect ratio). That's only 45 lumens/ft², however, it is equal to 5000 ft-candles, which is a bright summer day in Maine.

Professional greenhouses use W/m² for intensity, and J/cm² for energy (anybody know which instrument they use to measure it?). Of course, sun light is 100% uniform, and top to bottom. They also use plant activity meters and track it throughout the day! o.o

for multiple luminaires, he recommends 1.25m between lights, and 1.75m between rows (49" x 69"). They can be hung even higher than 60 cm to achieve the 1000 umol/m²s, with better than 90% uniformity.

It just goes to show how a piss poor reflector wastes energy, and reduces yields. And don't go by watts...get a umol meter and test.

 

[outwest]

I just picked up a Gavita Pro 1000 DE. Whazzup (on an international forum) recommends 1000 umol/m²s, and 1500 max given a perfect environment and CO2. Hung 24" above the canopy, it will light a 48" x 65" area (it casts a rectangular footprint with a 1:1.35 aspect ratio). That's only 45 lumens/ft², however, it is equal to 5000 ft-candles, which is a bright summer day in Maine.

Based on that data what's the canopy penetration like?

outwest

 

[Crysmatic]

great question. I'm not sure. Better than any existing HPS on the market (based on 15% brighter bulb, and 10-30% more effective reflector). I haven't even asked about the 1150w mode, which is not just a 'super lumen' mode...it's actually overdriving the bulb to 1150w (1220w consumption). someone will have to test it

 

[outwest]

great question. I'm not sure. Better than any existing HPS on the market (based on 15% brighter bulb, and 10-30% more effective reflector). I haven't even asked about the 1150w mode, which is not just a 'super lumen' mode...it's actually overdriving the bulb to 1150w (1220w consumption). someone will have to test it

Cool. Considering putting 2 of those in a 4x6 (closer to a 5x7). I've run 1200w in a 4x4 with no ill effect or bleaching, as long as I can keep things cool, plants are fine.

I know the gavitas run cooler, but I'm running 600w ac hoods now. Wonder what kind of temp adjustments I'd have to make to keep things cool if I went with 2 1000w gavitas.

outwest

 

[Crysmatic]

A 1000W at 1500 umol/m²s covers roughly 15 ft², or 40" x 54". Two lights will cover 54" x 80"...which is your 5'x7'. A single light would be placed approx 20" above the canopy. Of course, the light and wall interaction complicate things (verify with a PAR light meter). Per whazzup, align the bulb with the long side, and space them 49" apart. You don't have much choice in your tent. It's a good thing you can run them at 600W :)

I'm putting 2000W in a 100 ft² room...so I have lots of buffer. I will find out what I need to do to manage my room conditions.

I found out tonight that greenhouses use "sunshine meters" to measure light energy; probably not too useful to indoor grows. PAR light meters seem to be the next best. I found that Apogee makes a quantum meter - $400. They also have a chlorophyll meter, to measure your leaves' activity. I know greenhouses use plant activity (PA) monitors, linked to computers, and automatically controls fertigation schedules. :O

 

[outwest]

It's a good thing you can run them at 600W :)

Thanks for all the insight. So are you suggesting that I should not run these full blast in a 4x6? I'm currently running 2 AC 600w HPW with an LEP stuck in between.

outwest

 

[whazzup]

Direct communication is so much easier... ;)

This is my answer on ICmag. Sorry guys, I can't keep up with all the forums.

lol well I would not try to penetrate with a double ended lamp, though it is not a wide as a single ended it has a nasty wire at the end :D

The penetration into the crop depends on three things:
1. The density and intensity of the light source
2. The reflector
3. The overlap of the lamps (penetration in the crop)

1. Density and intensity
At 2070 umol s-1 you can not find a brighter lamp. Also if you look at the light in the shop you will notice that the light is more intense than other 1000W lamps, because the arc tube is smaller (a higher light density).

2. The efficient reflector is designed to bring light down, while having a 120 degrees spread to overlap with other fixtures. General remark: forget inverse square law. That works only for point sources without reflector and at 5x the maximum length of the light source.

3. When overlapping lamps in a light plan you will see that going further away from the lamps the intensity will not diminish as much as a single lamp. You also will get a much better penetration using overlapping lamps because of the wide reflector spread.

1150W setting will give you 15% more light, as the efficiency is maintained in this overdrive setting. You will use 15% more energy. The spread is defined by the reflector, so it will stay the same. However, you need to take more distance from the reflector (a minimum of 70 cm) so you will have a bit more overlap using more reflector, which adds to the uniformity.

We use Licor meters with cos corrected quantum sensors, but for hobby use there are other meters available as well. Though these are not as precise to use because the sensor will not be as linear as the Licor, they are much better equipped for light measurement that the lux meters. They work with a multiplication factor for the different types of lamps because the don't have a linear frequency response.

Sensors need to be calibrated every 2 years.

Though a Licor 250a with sensor is an expensive piece of equipment and you don't need it every day, so this is a great tool to share among a group of growers. I know a few shops that have them available for their customers to measure their rooms.

The Apogee MQ-200 is more reasonably prices and also sold as OEM by some companies, such as sunlight supply.

 

[outwest]

Direct communication is so much easier... ;)

This is my answer on ICmag. Sorry guys, I can't keep up with all the forums.

Thanks, wassup. Not sure if the answer to my questions was yes or no, but it seems yes. :D

outwest

 

[whazzup]

2x 600 with LEP inbetween is a great configuration because of a few reasons:

1. with two 600W you have a much better uniformity and penetration because you use 2 fixtures
2. You can come close to the plants if you don't have a lot of height
3. You can make a square field with 2x 600W if you wish, the plasma also has a square field.
4. The plasma can hang in the middle, that's hard with 1 1000W fixture ;)

 

[outwest]

2x 600 with LEP inbetween is a great configuration because of a few reasons:

1. with two 600W you have a much better uniformity and penetration because you use 2 fixtures
2. You can come close to the plants if you don't have a lot of height
3. You can make a square field with 2x 600W if you wish, the plasma also has a square field.
4. The plasma can hang in the middle, that's hard with 1 1000W fixture ;)

Thanks! I was actually thinking about 2 1000w gavitas. :D

outwest

 

[whazzup]

4x6 ~ 1.2 x 1.8m is a bit more than 2 square meters. 2x1000W is a lot of overkill!! Don't do it!

4200 umol HPS + 300 umol plasma = 4500 umol over 2 square meters so over 2000 umol per meter.... That is a lot of overkill and you will be forced to dim your fixtures down to 660, so 600W is more efficient. A 600W lamp at 100% will give you the more light than a 1000W lamp dimmed to 660. Dimming decreases efficiency of a lamp.

 

[outwest]

4x6 ~ 1.2 x 1.8m is a bit more than 2 square meters. 2x1000W is a lot of overkill!! Don't do it!

4200 umol HPS + 300 umol plasma = 4500 umol over 2 square meters so over 2000 umol per meter.... That is a lot of overkill and you will be forced to dim your fixtures down to 660, so 600W is more efficient. A 600W lamp at 100% will give you the more light than a 1000W lamp dimmed to 660. Dimming decreases efficiency of a lamp.

So what you are saying is the 2 600s plus an LEP is ideal for a 4x6? Thanks for your prompt replies to my silly questions!

outwest

 

[ttystikk]

So what you are saying is the 2 600s plus an LEP is ideal for a 4x6? Thanks for your prompt replies to my silly questions!

outwest

I understand whazzap's reservations about recommending two 1000DEs in a 4x8 tent, but I'm currently running a 1kW MH in an adjust-a-wing in my 4x8 tent, and it looks like it could easily absorb the light of a second if I wanted...

That's before the increased efficiency of the 1000DE is factored in, however; 2.07 umol/watt vs ~1.6 for the competition, plus a better reflector, plus the lack of glass that gets dirty... Quick back-of-napkin calculations have it approaching double the light pressure of a conventional sealed and ducted mogul socket style 1kW fixture. That number climbs, of course, as the lights burn for month after month, 'cuz the Gavitas don't dim more than 5% over the course of 3 full years. Depending on brand, the screw-in 1Ks often lose that much in their first month of use!

Texas Kid started a thread around here someplace where he discussed several lighting setups he'd tried, one of which was a 4x4 tent with both a 1kW HPS AND a 1kW MH! If I recall correctly, he said it was awesome, but definitely pushing the limit and there was no way he could see to scale it up and still keep the temps under control.

Bottom line? I'd try it; mount the hoods up pretty high in the tent, keep my temps in the mid 80s, my RH around 70% (and rock stable or the plants fry), and CO2 cranked up to 1500ppm. Near the end of flower, I'd dial the Gavitas back and go for cooler, drier conditions with the flush. I bet it would make for crazy dankness... This would only work with plants that were properly hardened off to this kind of light intensity beforehand, like exposure to sunlight or high wattage HID.

 

[dankworth]

I ran 120 watts/ft2 overhead back in the day. Was too much.
Maybe taller plants w/2 6s overhead + the lep, but with a third 6 added vert in a cool tube to light lowers would be better. 2 1ks overhead will almost certainly be too much IMO.
This is assuming you have the ceiling height needed for such a configuration.

 

[whazzup]

you need to take into consideration the following:

1. A normal MH can be almost half as efficient as an HPS. Great in lumens, bad in micromoles. Anything that is bright for your eyes isn't necessary bright for a plant.
2. You need to change the MH every 6-8 months latest, as their light maintenance is not very good

Based on our tests en tests from users I would really use a 5x5 for a Gavita 1K. 4x4 can be done but that is really pushing it! In a small room there is always much light loss from the walls. So hanging your fixtures even higher will cause more losses = less light on the plants.

4x4 is a comfortable space for a 600W lamp, where you still easily can add a plasma lamp.