load testing power draw of various light fixtures

i thought i'd break this out into it's own thread, originally part of this thread.

i've been testing everything i can get my hands on with my new $30 appliance load tester. got some unexpected results from T8 fixtures.

anybody else have a load tester? please post results. here are input wattages of light fixtures i have access to:

cheap-ass 4ft dual T8, 2x32 watt bulbs = 210 watts (146 watts or 228% difference)
not-quite-as-cheap 4ft quad T8, 4x32 watt bulbs = 413 watts (285 watts or 223% diff)
cheap-ass 2ft dual T12, 2x20 watt bulbs = 73 watts (33 watts or or 83% diff)
hydrofarm 2ft octo HOT5 with 8x24 watt bulbs = 247 watts (55 watts or 29% diff)

lumatek 600 watt ballast + 600 watt HPS bulb:
- 600 watt mode = 635 watts (6% diff)
- 400 watt mode = 435 watts (9% diff)
- 360 watt mode = 400 watts (11% diff)

lumatek 400 watt ballast + 400 watt HPS bulb:
- 400 watt mode = 443 watts (11% diff)
- 275 watt mode = 310 watts (13% diff)
- 250 watt mode = 290 watts (16% diff)

conclusion: (1) cheap ass T8 fixtures are a total waste; (2) it is more efficient to run a HPS (and i presume MH as well) on a 600 watt ballast that has been dimmed down; (3) T12s are totally useless; (4) one should consider running 250 watt MH on a dimmable 400 watt ballast (~21,000 lumens, 290watts) rather than an 8xHOT5 (~16,000 lumens, 247 watts); (5) don't just look at how many lumens per bulb watt you get but also consider the input wattage of the ballast, which can be significantly more.

cervantes says you get 100 l/w out of a 32w T8 bulb. so total lumens of the bulb he tested (or is reporting on) is 3200 lumens. my quad T8 fixture draws 413 watts. so 3200 lumens x 4 = 12,800 lumens. 12,800 lumens / 413 watts = 31 lumens/watt. that's slightly better than a halogen bulb.

my 23watt CFL drew 106 watts. again, cervantes claims 70 l/w average for CFLs, so my 23watt CFL should be putting out somewhere around 1610 lumens. 1610 lumens / 106 watts = 15 lumens/watt. a 100watt incandescent bulb gives you 17.5 lumens/watt. aside from generating less heat (which i grant, is important in grow rooms), the "23 watt" CFL rating is very misleading. it uses just as much power, has just as much of a carbon footprint, and is even toxic. what a scam.