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Lights account for a significant portion of our electrical usage...

While we obviously need to have proper lighting for areas that are in use, but in some cases we leave the lights on when an area is not in use. For example, empty classrooms, and restrooms, are often left with all the lights on.

Sometimes rooms and hallways are over-lit. Standards exist to help guide lighting of areas according to their use and are expressed in fc (foot candle: the amount of light received at a distance of one foot away from a "standard" candle):

Recommended Lighting levels

Reading and writing: 30 fc

Computer Room: 20 fc

Hallway: 10 fc

A group of students and I have been taking light level readings across campus. Here is a sample of lighting energy waste:


Hallway of the Life Science Office building: 10.3 fc

Library computer lab: 49.1fc


Wentworth Hallway: range walking down the hall from 40fc (between light fixtures) to 120 fc (which is the recommended light level for doing surgery)

Science and Technology Hallway: range walking down the hall from 10fc (good) to 110 fc (lit for surgery)

STB 226: 85.9 fc

STB 108 Light Setting #1: 61 fc

Light setting #2 38 fc,

Light setting #3: 38 at the top of the class, 30 fc in the middle, 20 near front

Agriculture Building room 203: 99.6fc

Agriculture Building 201: 133fc

UCB 101:78.8fc

CH 7(computer lab): 65fc

Campus Center 211: 80.5fc

CC210: 68fc

K128: 80.1fc

CH 11A: 66.3fc

K126: 87.7fc

CH 6: 91.1fc