June 10, 2002
CRITERIA FOR SPECIFIC FACILITIES.
F-15.1.1 Lighting System Selection. Refer to IESNA/ANSI RP-1. The choice of
appropriate lighting systems for offices varies according to need and budget. Recessed
troffer systems offer value and get the job done at lowest cost; suspended lighting
systems improve comfort and visual quality. At the same time, all interior lighting for an
office building should not exceed 1.2 watts per 0.1 square meter or (1 square foot) (task
lights not included), with a minimum of about 0.8 watts per 0.1 square meter (1 square
foot) under ideal conditions. Unless a project has unusual requirements, such as
considerable engineering or medical labs, expect most projects to fall within this power
F-15.1.2 Direct Lighting Systems.
F-126.96.36.199 Parabolic troffers are common office lighting systems, with about the same
energy efficiency and layout considerations as for lensed luminaires. Standard 3 -inch
louver luminaires cost more than lens troffers but improve performance in larger rooms
with respect to computers. Because most office spaces involve the use of computer
work stations, parabolic troffers should be the first choice for a direct lighting system.
Parabolic troffers also provide a more attractive office appearance than lensed troffers.
Take care when using parabolic troffers that vertical surfaces in the room are
adequately lighted; otherwise, the room can have a dark appearance. Louvers should
have a plastic cover that is removed after installation or have an organic finish that will
not show fingerprints. Plastic louvers should not be used.
F-188.8.131.52 While not suited for computer work in large open areas, lens troffer lighting
systems work for most other office building lighting situations. A typical layout employs
3 lamp luminaires on 2.4 by 3.1 meters (8 feet by 10 feet) centers and can produce
appropriate lighting levels at around 0.95 to 1.15 watts per 0.1 square meter (1 square
foot). A better layout employs 2-lamp luminaires on 2.4 by 2.4 meter (8 feet by 8 feet)
spacing with improved uniformity of light distribution. Existing lighting systems of this
type can be retrofitted with modern T-8 lamp/electronic ballast technology to equal the
performance of new systems.
F-15.1.3 Suspended Lighting Systems.
F-184.108.40.206 Lighting systems that hang down from the ceiling--fluorescent indirect and
direct/indirect systems--are considered an important upgrade in visual comfort and the
appearance of the space.
F-220.127.116.11 Indirect lighting systems cost very little more overall than parabolic troffers.
These systems tend to be simple in design and appearance.
F-18.104.22.168 Styled, high performance indirect and direct/indirect lighting systems perform
especially well in computer workspace in addition to making an architectural statement.
At the same time, all interior lighting for an office building should not exceed 1.2 watts per 0.1 square meter or (1 square foot) (task lights not included), with a minimum of about 0.8 watts per 0.1 square meter (1 square foot) under ideal conditions. F-22.214.171.124 While not suited for computer work in large open areas, lens troffer lighting systems work for most other office building lighting situations.