UFC 3 -520-01
June 10, 2002
recessed troffer every 6 square meters in a 2.4 meters by 2.4 meters grid (64 square
feet in an 8 feet by 8 feet grid) or a three-lamp recessed troffer every 7.4 square meters
in a 2.4 meters by 3 meters grid (80 square feet in a 8 feet by 10 feet grid) provides an
average of 40 to 60 footcandles maintained. These systems can produce the
necessary illumination for many typical interior spaces at about 0.95 watts 0.1 square
meter (per square foot). In new luminaires, there is little need for specular silver or
aluminum reflectors. The increase in efficiency is only a couple of percent, and the cost
is usually not warranted. Do not use silver or polished reflectors in parabolics as they
create glare. Paragraphs F -15.1 through F -15.1.3 provide additional guidance
regarding the selection of troffer systems.
F-8.2.3 Wraparounds. Wraparounds are relatively low cost fluorescents designed to
have a finished appearance whether surface mounted or suspended by pendants. The
luminaire is essentially a strip light with a U -shaped diffuser or lens surrounding the
lamp on three sides, producing some uplight as well as widely distributed downlight.
One and two lamp "wraps" are used in corridors, stairs, and a variety of general lighting
and utility applications. Four -lamp wraps are often used for the office and retail lighting,
as well as some types of "clean" industrial lighting.
F-8.2.4 Industrial Fluorescents. Industrial fluorescent luminaires can be used in a
variety of shops, service facilities, and other work and utility areas. They can be surface
mounted, suspended from stems or on chains, or strapped to the bottom of building
structural members. The reflector increases downward light as compared to a strip
light, making industrial fluorescent luminaires more efficient for illuminating work
F-8.2.5 Watertight Fluorescents. These are a form of fluorescent luminaire that
permit use in wet environments and allow hose-down cleaning. Watertight fluorescents
can be specified with non-metallic housings for corrosion resistance.
HID Lighting Systems.
F-8.3.1 Industrial HID Luminaires. HID luminaires have been optimized for typical
industrial and work area applications. The optics of these luminaires are optimized for
various distributions and mounting heights. High bay luminaires are designed for
mounting heights over 6.1 to 7.6 meters (20 to 25 feet); low bay luminaires are designed
for mounting less than 7.6 meters (25 feet) above the floor or work plane. Some
luminaires are mostly direct, with uplight of 5 to 20 percent to improve visual comfort.
F-8.3.2 Floodlights. These are HID luminaires designed for exterior floodlighting.
Most general-purpose floodlights are designed for very wide distribution, but in some
cases floodlights with specific distribution patterns might be required.
F-8.3.3 Roadway, Parking Lot, and Outdoor Area Lighting. HID luminaires are
preferred for outdoor drive and lot lighting. The most common luminaire types used in
these applications are cobra head general-purpose luminaires and shoebox cutoff
luminaires. Cutoff luminaires are preferred to minimize light pollution and light trespass.