Page 211 - Alternative Energy Systems in Building Design

CALIFORNIA TITLE 24 ELECTRIC ENERGY COMPLIANCE 187

Figure 5.7 Photosensor-
control wiring diagram.
Courtesy of LCD.

Complete-Building Method This method applies to situations in which the entire
building’s lighting system is designed and permitted at one time. This means that at
least 90 percent of the building has a single primary type of use, such as retail. In the
case of wholesale stores, at least 70 percent of the building area must be used for mer-
chandise sales functions. In some instances, this method may be used for an entire ten-
ant space in a multitenant building where a single lighting power value governs the
entire building.

Area-Category Method This method is applicable for any permit situation,
including tenant improvements. Lighting power values are assigned to each of the
major function areas of a building, such as offices, lobbies, and corridors.

Tailored Method This method is applicable when additional flexibility is needed
to accommodate special task lighting needs in specific task areas. Lighting power
allowances are determined room by room and task by task, with the area-category
method used for other areas in the building.

Performance Approach This method is applicable when the designer uses a
CEC-certified computer program to demonstrate that the proposed building’s energy
consumption, including lighting power, meets the energy budget. This approach incor-
porates one of the three previous methods, which sets the appropriate allowable light-
ing power density used in calculating the building’s custom energy budget. It may be
used only to model the performance of lighting systems that are covered under the
building permit application.

Actual Adjusted-Lighting-Power Method This method is based on the total
design wattage of lighting less adjustments for any qualifying automatic lighting con-
trols, such as occupant-sensing devices or automatic daylight controls. The actual
adjusted lighting power must not exceed the allowable lighting power for the lighting
system to comply.

Lighting tradeoffs The intent of energy-control measures is essentially to restrict
the overall installed lighting power in the buildings regardless of the compliance