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© Red Leonard Associates, Inc.
All rights reserved.
©
Red Leonard Associates, Inc.
All rights reserved.
If you work anywhere in the lighting industry, you have likely heard of BUG
Ratings. These help light designers and cities alike understand where the light is going to bleed
off to.
A: BUG Ratings of parking lot lights stands for backlight, uplight
and glare. In light design, all 3 of these are attempted to be minimized but no fixture is perfect.
Fixtures that reduce these three classifications of light help improve light quality, light harshness and dark
sky compliance.
A: Light fixtures calculate lumens, light direction and colors by
going into a round sphere called an integrating sphere. This sphere fully encloses a fixture
allowing for the light to be measured at every point in a 360 degree fashion. The sphere enables exact
measurements of lumens regardless of the directionality of the fixture. The resulting file can be
used to model up light installations for planning, permitting and other functions.
| ZONE | LUMENS | % LAMP LUMENS |
|---|---|---|
| FORWARD LIGHT | 24190 | 63.2 |
| FL (0° - 30°) | 4290 | 11.2 |
| FM (30° - 60°) | 12061 | 31.5 |
| FH (60° - 80°) | 7133 | 18.6 |
| FVH (80° - 90°) | 707 | 1.8 |
| BACKLIGHT | 13984 | 36.5 |
| BL (0° - 30°) | 3362 | 8.8 |
| BM (30° - 60°) | 6693 | 17.5 |
| BH (60° - 80°) | 3622 | 9.5 |
| BVH (80° - 90°) | 307 | 0.8 |
| UP LIGHT | 99 | 0.3 |
| UL (90° - 100°) | 26 | 0.1 |
| UH (100° - 180°) | 73 | 0.2 |
| TRAPPED LIGHT | N/A | N/A |
BUG (Backlight, Uplight, Glare) Rating based on TM-15-11
| Asymmetrical Luminaire Types (Type I, II, III, IV) |
B4 U5 G4 |
| ZONE | LUMENS | % LAMP LUMENS |
|---|---|---|
| FORWARD LIGHT | 11708 | 61.5 |
| FL (0° - 30°) | 2322 | 12.2 |
| FM (30° - 60°) | 5793 | 30.4 |
| FH (60° - 80°) | 3169 | 16.6 |
| FVH (80° - 90°) | 425 | 2.2 |
| BACK LIGHT | 7297 | 38.3 |
| BL (0° - 30°) | 1785 | 9.4 |
| BM (30° - 60°) | 3506 | 18.4 |
| BH (60° - 80°) | 1829 | 9.6 |
| BVH (80° - 90°) | 176 | 0.9 |
| UP LIGHT | 47 | 0.2 |
| UL (90° - 100°) | 9 | 0.0 |
| UH (100° - 180°) | 38 | 0.2 |
| TRAPPED LIGHT | N/A | N/A |
BUG (Backlight, Uplight, Glare) Rating based on TM-15-11
| Asymmetrical Luminaire Types (Type I, II, III, IV) |
B3 U2 G3 |
| ZONE | LUMENS | % LAMP LUMENS |
|---|---|---|
| FORWARD LIGHT | 38515 | 79.2 |
| FL (0° - 30°) | 4684 | 9.6 |
| FM (30° - 60°) | 20370 | 41.9 |
| FH (60° - 80°) | 12735 | 26.2 |
| FVH (80° - 90°) | 726 | 1.5 |
| BACK LIGHT | 9913 | 20.4 |
| BL (0° - 30°) | 1767 | 3.6 |
| BM (30° - 60°) | 4982 | 10.3 |
| BH (60° - 80°) | 2921 | 6.0 |
| BVH (80° - 90°) | 242 | 0.5 |
| UP LIGHT | 175 | 0.4 |
| UL (90° - 100°) | 35 | 0.1 |
| UH (100° - 180°) | 141 | 0.3 |
| TRAPPED LIGHT | N/A | N/A |
BUG (Backlight, Uplight, Glare) Rating based on TM-15-11
| Asymmetrical Luminaire Types (Type I, II, III, IV) |
B4 U3 G5 |
A: BUG ratings are designed and maintained by the IES based on their published
spec TM-15-11.
A: BUG ratings are based on hard lumens.
The challenge with BUG ratings is that we calculate light by direction or angle and then its summarized into categories. Only certain percentages are considered to be harsh light, IES defines these "zonal lumens" as follows: