My grow "area" is equipped with 4 CFLs that put out the equiv. of 100 watts each. So far they've worked great, but hear is my question:
Does using 4x100 watts = 400 watts?
How does this math work, please and thank you?
Sorry if any of this is just obvious, or way TMI but I thought I would put it out there ...
Most people refer to CFLs in terms of actual power, and not equivalent. Equivalent only matches the light output of incandescent bulbs ( what they were intended to replace ) relative to the CFL. The actual wattage should be reported on the base of the bulb, where the little ballast is.
True watts is only a measure of power, and indirectly, heat.
Lumens are the measure of total light as perceived by the human eye. It is not a measure of the usable light to a plant. It is cumulative as you use more bulbs - just add them up. Be aware though that the amount of light that your plant gets is a function of your space, distance, reflectivity and spectrum, which are variable. You can say you have so many watts CFL or lumens, but there are other factors that effect how the plant gets the light and what intensity it is.
Efficiency is how many lumens are produced by an amount of power. This changes by bulb type.
23w CFL = 1600 Lumens = Efficiency is 1600/23 or about 70 Lumens per watt. ( good )
600w HPS = 95000 Lumens = Efficiency is about 160 Lumens per watt. ( great )
Watts = Heat :
A 250 W HPS and 250 W total of CFL bulbs will produce the same amount of TOTAL heat, but the HPS will put out quite a bit more light, and the heat will be highly concentrated at the one bulb.
Opinion :
Use at least 40-50 W of CFL per 12" plant with the light well distributed. Of course, more is better.
I wish you much bud