Since I'm in
<3 with
Compact Fluorescent Lighting (CFL) I wanted to spend some time today to share with you what I've found during my hours of research.
Not only are these the best way to light
(cost, efficiency, growth) vegetation for the least amount of money spent in intial costs and expenses of operating the lights they are flexible enough to be used in extremely small spaces. They produce very low amounts of heat allowing them to be placed directly next to the vegetation.
After all,
'compact' is in the name!
Since we are recreating the outside invironment inside we must work with at least
10,000 Lumens per square foot as the sun produces that much light, on average, on Earth during a sunny summer day.
Here is an equation every inside grower should have burnt into their brains:
The Inverse Square Law
E = I / r*r
E = Illuminance
I = Pointance
r = Distance
Illuminance is the amount of light emitted over an area, whether you are using Metric or Standard measurement, produced by the
Pointance (source of light) at a specified
Distance.
For example, 1 unit of distance from the Pointance to the perpendicular object would calculate as such:
E = I / 1*1
If we assume the Pointance is producing 10,000 Lumens (L):
E= 10,000L / 1*1
E = 10,000L per square unit area
If the Pointance is situated at 2 units of distance above the perpendicular object, assuming the pointance is producing 10,000L:
E = 10,000L / 2*2
E = 2,500L per square unit of area
That is one
fourth (1/4) of the light per 1 square unit of area. This means, if the pointance is twice the distance it will require
four times the light to cover the area with 10,000L.
E = 40,000L / 2*2
E = 10,000L per square unit area.
Given this knowledge of how light
spreads over an area,
not diminishes, the CFL's have an obvious advantage over high-intensity discharge (HID) lamps. HID lamps produce so much heat that they require distance from the canopy of vegetation to prevent burning and potential destruction of the vegetation.
For example, a high-pressure sodium (HPS) lamp producing 95,000L per 600 watts (w) of energy consumed (158.3L/w) situated 4 units of distance above the canopy would look like this:
E = 95,000L / 4*4
E = 5,937.5L per square unit area
Same equation with a 1000w HPS producing 140,000L (140L/w):
E = 140,000L / 4*4
E = 8,750L per square unit area
Notice how the 600w HPS is more efficient in terms of L/w than the 1000w a the same distance. The 600w HPS is producing
158.3L/w and the 1000w HPS produces
140L/w.
With proper ventilation, or even water-cooling, the HPS can be set closer to the canopy (within 2 ft.). This is of course costs quite a bit of money while the CFL's can be set right next to the canopy with no extra equipment and a very low initial cost.
One 600w lamp can be had for
$100.00, then there is the hood/reflector, socket/cord, ballast, and ventilation/water-cooling. This could easily add up to
$1,000. The 1000w counter-part is around the same price.
Now, lets compare some CFL's to each other and then back to the HPS lamps. Keep in mind that CFL's are *self-ballasted* (the ballast regulates the electricity to maintain a steady current).
These do not require anything special, household socket and wiring will work:
13w; 700L = 53.8L/w
15w; 900L = 60L/w
26w; 1,700L = 65.3L/w
30w; 2,000 = 66.7L/w
32w; 2,100L = 65.6L/w
40w; 2,800L = 70L/w
55w; 3,600L = 65.5L/w
These require special sockets, but standard household cords:
125w; 8,000L = 64L/w
150w; 10,000L = 66.7L/w
200w; 12,000L = 60L/w
250w; 15,000L = 60L/w
One more factor to consider is the HID's wear out quickly. Through half of their life the light emitted could drop as much as
50% and they will still look bright as hell. The CFL's generally just go out. I've sure the quality degrades a bit, but since they aren't as hot as the HID's they will maintain light out-put better longer.
All of the CFL's listed can be had for under
$100 and only the big ones need the special socket and standard household cord. With heat still being emitted from these CFL's you'll only need a simple fan (you should already have these for circulation) to cool the growing space.
Since the CFL's can be placed right on the canopy you can pretty much throw out the Inverse Sqaure Law. Not only that, but they come in the
blue and
red lighting spectrum for all stages of growth.. for the
SAME price.
Now that we've compared the CFL's to themselves lets find the most efficient CFL's (L/w) and compare them to the HPS lamps.
CFL:
40w; 2,800L = 70L/w
150w; 10,000L = 66.7L/w
HPS:
600w; 95,000L = 158.3L/w
1000w; 140,000 = 140L/w
In order for a CFL to match the
initial lumen output of the HPS it would take:
34 - 40w CFL's
9.5 - 150w CFL's
Now, let's apply that nifty little equation from the beggining of this thread:
The Inverse Square Law
E = I / r*r
E = 95,000 / 4*4
E = 5,937.5L per square unit area
E = 140,000 / 4*4
E = 8,750L per square unit area
Since the CFL's produce very little heat compared the HPS lamps they will be placed right next to the canopy practically negating the Inverse Square Law in this setup.
Now, let's see how many lumens can be spread over a 4x4 area with CFL's:
34 - 40w CFL's = 95,200L
10 - 150w CFL's = 100,000L
Now, let's divide that total Lumen output by 16 (4x4) to see what we get over a 1x1 area:
34 - 40w CFL's = 5,950L per square unit area
10 - 150w CFL's = 6,250L per square unit area
Keep in mind we are trying to get at least 10,000L per square unit area, that would still take two 600w HPS.
Since the CFL's are
compact they can be used in much smaller, more efficient designs.
Let's say we can fit this into a 2x2:
34 - 40w CFL's = 95,200L
10 - 150w CFL's = 100,000L
34 - 40w CFL's =
23,800L per square unit area
10 - 150w CFL's =
25,000L per square unit area
Given different designs, light placement, soil or hydro, ScroG, SoG, supplimental lighting, nutrition, and grower experience will
ALL affect the end yield.
As you can see from the math the CFL's have a very good chance of being equivalent to the HPS.. and even surpassing them with Lumens given an area.
Another huge factor is the
Color Rendering Index (CRI). Most HPS lights only provide up to 80% CRI. While CFL's claim 100% CRI. CRI is how well the lamp can recreate natural sun light.
Remember, anyone can get these CFL's at almost any store these days. They use normal sockets, except for the big ones, and normal household plugs. The price is noticably cheaper and easier to maintain.
Just something to think about with your current setup or a noOb starting out in their closet.
Enigma
