ttystikk
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- Jan 4, 2011
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Let me repeat something from the last post, because I think it underlines perhaps the biggest under-recognized power and efficiency drain of the whole lighting enchilada; the light depreciation curve of all HID lights, HPS especially.
You guys have heard the growers talk about bulb replacements; a new set every 2 cycles, or even every one. Why? Because of lumen depreciation, of course- but how much? And just how quickly? I haven't seen a lot of graphs, but if it becomes necessary to change the bulbs every 1000-1500 hours due to light loss, then I would say there's a lot of inefficiency left on the table; just how long do they maintain their rated value, anyway? For replacement to make sense, I am guessing that the bulbs lose 10-15% of their rated PAR. OR MORE. It's that second part that especially concerns me.
You see, lighting is the single most expensive part of most growing operations. It's expensive to buy the gear, distribute the light, upgrade the wiring... and of course, pay the bill every month. The bigger the op, the bigger the bills.
I think that once you consider that standard 1kW HPS bulbs gradually but constantly lose PAR efficiency from the very first moment they're lit- adding up to a loss of some 15% by the time it's retired at the end of 1 or 2 crops, the fact that a Philips/Gavita bulb that does NOT dim more than 1% per 2000 hours of operation- 3 crops- becomes an energy saving efficiency proposition, not just a bulb maintenance issue. Okay, so change the bulbs yearly if you must- but with that kind of performance maintenance, the lumens you gain every day more than outweigh the extra initial expense- and then the lower bulb replacement cost pays for itself!
Nevermind that better lighting consistency from one crop to the next allows you to eliminate that worry from your mind every new run in the quest to dial things in ever better. Yields won't decline, costs are contained.
You guys have heard the growers talk about bulb replacements; a new set every 2 cycles, or even every one. Why? Because of lumen depreciation, of course- but how much? And just how quickly? I haven't seen a lot of graphs, but if it becomes necessary to change the bulbs every 1000-1500 hours due to light loss, then I would say there's a lot of inefficiency left on the table; just how long do they maintain their rated value, anyway? For replacement to make sense, I am guessing that the bulbs lose 10-15% of their rated PAR. OR MORE. It's that second part that especially concerns me.
You see, lighting is the single most expensive part of most growing operations. It's expensive to buy the gear, distribute the light, upgrade the wiring... and of course, pay the bill every month. The bigger the op, the bigger the bills.
I think that once you consider that standard 1kW HPS bulbs gradually but constantly lose PAR efficiency from the very first moment they're lit- adding up to a loss of some 15% by the time it's retired at the end of 1 or 2 crops, the fact that a Philips/Gavita bulb that does NOT dim more than 1% per 2000 hours of operation- 3 crops- becomes an energy saving efficiency proposition, not just a bulb maintenance issue. Okay, so change the bulbs yearly if you must- but with that kind of performance maintenance, the lumens you gain every day more than outweigh the extra initial expense- and then the lower bulb replacement cost pays for itself!
Nevermind that better lighting consistency from one crop to the next allows you to eliminate that worry from your mind every new run in the quest to dial things in ever better. Yields won't decline, costs are contained.