for a project in lighting zone 3 (U3 allowance or 500 UL and 500 HL for total of 1000), I am reviewing a submittal for a light with the following performance data:
- Adjustable power settings at 18W, 24W, and 30W
- corresponding lumens of 2000, 3000, and 4000
- Glare-free lens
- Cylindrical with both uplight and downlight
- dimmable to 10%
- Mounting height table with forward throw & wall spread
These luminaires are located under a 3' deep roof overhang and are mounted 3.5' below the overhang. If they are dimmable, would these be deemed in compliance for uplight using the BUG Rating method since they could be limited to 1000 lumens of uplight through dimmer settings, or could they be deemed in compliance with a U0 rating given the roof overhang and mounting locations distance from the overhang? Thank you!
You'd need the IES file for the wattage fixture you want. Dimmable doesn't help. The peak output is used. 18W might be U3 but not the 30W. The overhand can reduce some light. You'd need to calculate how much is blocked and how much reaches the sky. U0 is zero uplight. It sounds like a quarter of the sky is still visible to the light. A downlight in the overhang would work.