Page 186 - Solar Power in Building Design The Engineer's Complete Design Resource

156 ENERGY CONSERVATION

California Title 24 Electric

Energy Compliance

In response to the 2000 electricity crisis, the state of California legislature mandated
the California Energy Commission (CEC) to update the existing indoor lighting
energy conservation standards and to develop outdoor lighting energy efficiency com-
pliant cost-effective measures. The intent of the legislature was to develop energy con-
servation standards that would reduce electricity system energy consumption.
Regulations for lighting have been enforced in California since 1977. However, the
measures only addressed indoor lighting through control requirements and maximum
allowable lighting power. Figure 6.8 depicts a local microprocessor-based control panel.

SCOPE AND APPLICATION

Earlier energy regulation standards only applied to interior and outdoor lighting of build-
ings that were air-conditioned, heated, or cooled. The updated standards, however,
address lighting in non–air-conditioned buildings and also cover general site illumination
and outdoor lighting. The standards include control requirements, as well as limits on
installed lighting power, and also apply to internally and externally illuminated signs.
For detailed coverage of the energy control measures and regulations refer to the
California Energy commission’s standard publications.

Indoor Lighting Compliance

In this section we will review the requirements for indoor lighting design and instal-
lation, including controls. This discussion is addressed primarily to lighting designers,
electrical engineers, and building department personnel responsible for lighting and
electrical plan checking and inspection purposes.
Indoor lighting is perhaps the single largest consumer of energy (kilowatt-hours) in
a commercial building, which amounts to approximately one-third of electric energy
use. The principal purpose of the standards is to provide design guidelines for the
effective reduction of energy use, without compromising the quality of lighting.
Figure 6.12 depicts lighting energy use in a residential unit.
The primary mechanism for regulating indoor lighting energy under the standards
is to limit the allowable lighting power, in watts, installed in the buildings.
Mandatory measures apply to the entire building’s lighting systems, and equipment
consists of such items as manual switching, daylight area controls, and automatic
shutoff controls. The mandatory requirements must be met either by prescriptive or
performance approaches, as will be described here. Figure 6.9 depicts a photosen-
sor control wiring diagram and Figures 6.10a and 6.10b depicts a photosensor con-
trol configurations.