BobCajun
Well-Known Member
You would think, but the Rapitest meter says otherwise, and I do grow plants with the 5w LED bulb. For those on a budget, it's a handy item, the Rapitest. An interesting thing I learned is how little light plants really need, 5000 fc. Maybe dim light distributed around the canopy would be better than using very high wattage above to try to blast through the upper layers.OK, this is plain wrong.
Sunlight is something like 98000 lux per square meter@ sea level, which works out to around 9100 lux per square foot - that's about 4260 lux higher than a 4000k CLU048-1212C4 running @ 1400ma (4840lm). These chips are around 40-45% efficient at that drive current, which is a hair under 50W. Here's the datasheet.
http://ce.citizen.co.jp/lighting_led/dl_data/datasheet/en/COB_6/CLU048-1212C4_P3949_0217_170410.pdf
my Veros produce around 12590lm @ ~81.3W. If you scale that back to 50W, that's about 7700lm @ 50w consumption (154 lm/w, rounding down). Here's the data sheet for that.
http://www.bridgelux.com/sites/default/files/resource_media/DS93 Vero 29 Array Data Sheet Rev A 20160622.pdf
So, somehow you've managed to obtain a 5w LED that 's making at least 1250lm/watt (or well over 500% efficient). That's unbelievable.
Literally, I do not believe it.
I'd believe you're producing 6700lm @ 50w with a CXB or similar emitter though.
Again, this doesn't address the fact that Foot Candles is an extremely out of date measure for light production. HPS weights much more heavily on this scale than natural sunlight due to the high fraction of green and yellow light. This is a relative measure for the purpose of determining light source brightness for the human eye. It does not take into account total photon production, nor the efficiency of the given spectrum for photosynthesis. This is why Quantum and PAR meters exist. Stop moving the goalposts on this argument.