Roseman
Elite Rolling Society
On the post a page back, Ed Rosenthal says he likes and prefers the 42 watt bulbs too.
High pressure sodium lights
- Thread starter cgrabo
- Start date
KaliKitsune
Well-Known Member
Oh, as a side note, I'd like to note that lumens don't physically add up like that. Were that the case a few CFLs would be brighter than the sun - don't we wish! You have to get into things like photon flux density and such to really determine the quality of the light you're using. 2700 lumens at two feet away from the lamp won't get any higher adding more lamps at the same height, the meter will still read 2700. At least with CFL you can just have them on individual lines and hang them where they're needed, so you can sustain a much larger plant just by putting a few bulbs around it.
Ed might be a little outdated in his ballast knowledge, however. If you get Energy Star rated stuff, it has to be 85% or better in efficiency, not the 70-80% that Ed's talking about. I've got 90% rated ballasts for my T5HO, so the 432w pulls 475 at the outlet. I've tested that with my kill-a-watt meter. My old 400w HPS uses 480 at the ballast, so that's more like 78% efficiency. But it's not Energy Star rated, so that would figure.
Ed might be a little outdated in his ballast knowledge, however. If you get Energy Star rated stuff, it has to be 85% or better in efficiency, not the 70-80% that Ed's talking about. I've got 90% rated ballasts for my T5HO, so the 432w pulls 475 at the outlet. I've tested that with my kill-a-watt meter. My old 400w HPS uses 480 at the ballast, so that's more like 78% efficiency. But it's not Energy Star rated, so that would figure.