I just completed a job where I swapped out existing 400W MH fixtures for T5 HO fluorescents. To be honest, I was skeptical of this project when it was pitched to me 2 months ago. The application is in a warehouse/distribution center with pick aisles 150' long, 50" wide and with shelving 28' high on each side. The existing lighting was 277V 400W MH fixtuers with alum reflectors. There were 5 fixtures per aisle and the ft candles were about 7 average with dark areas between fixtures registering 2 and the bright areas registering 12. The top 4' of the shelving was dark the whole length. The T5 fixtures were 8' long with 4 lamps and polished reflectors. I replaced the MH fixtures 1 for 1 with the T5s. What an unbeliveable difference! ft candles average 22 with the darkest areas 20 and the brightest at 24. Even lighting from top to bottom of shelving. Here's the kicker; the MH fixtures draw 460W and the T5s draw 234W. 3x the light for 1/2 the electricity! The T5 lamps do get toasty but this is a climate controlled building kept at a constant 74 degrees so the lighting rep says it isn't a concern. The warranty is 5yrs ballast and 5yrs lamp. I did this 50k sq.ft. area first and they are happy. I have 150k sq.ft. to go. The fixtures on each end of the aisles stay on all of the time and the ones in between have bisymetrical motion sensors with a 5 minute delay so the energy savings will be even greater over MH. The ballasts are program start so switching isn't supposed to shorten their lifespan. This was my first experience with T5 HO fixtures and I haven't read too much about them on the forum so I just thought I'd share.
