Page 194 - Solar Power in Building Design The Engineer's Complete Design Resource

164 ENERGY CONSERVATION

Area controls. The best way to minimize energy waste and to increase efficiency is
to turn off the lights when they are not in use. All lights must have switching or con-
trols to allow them to be turned off when not needed.

Room switching. It is mandatory to provide lighting controls for each area enclosed
by ceiling height partitions, which means that each room must have its own
switches. Ganged switching of several rooms at once is not permitted. A switch may
be manually or automatically operated or controlled by a central zone lighting or
occupant-sensing system that meets the mandatory measure requirements.
Accessibility. It is mandatory to locate all switching devices in locations where per-
sonnel can see them when entering or leaving an area. In situations when the
switching device cannot be located within view of the lights or area, the switch posi-
tion and states must be annunciated or indicated on a central lighting panel.
Security or emergency. Lights within areas required to be lit continuously or for
emergency egress are exempt from the switching requirements. However, the light-
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ing level is limited to a maximum of 0.5 W/ft along the path of egress. Security or
emergency egress lights must be controlled by switches accessible only to author-
ized personnel.
Public areas. In public areas, such as building lobbies and concourses, switches are
usually installed in areas only accessible to authorized personnel.

Outdoor Lighting and Signs

In response to the electricity crisis in 2000, the California legislature mandated the
CEC to develop outdoor lighting energy efficiency standards that are technologically
feasible and cost effective. The purpose of the legislature was to develop energy effi-
ciency standards that could provide comprehensive energy conservation.

OUTDOOR ASTRONOMICAL TIME SWITCH CONTROLS

As briefly referenced earlier, outdoor lighting control by means of astrological time
switches is permitted if the device is designed to accommodate automatic multilevel
switching of outdoor lighting. Basically, such a control allows all, half, or none of the
outdoor lights to be controlled during different times of the day, for different days of
the week, while ensuring that the lights are turned off during the daytime.
Energy control measures for outdoor lighting and signs are intended to conserve
energy and reduce winter peak electric demand. The standards also set design direc-
tives for minimum and maximum allowable power levels for large luminaires.
Permitted lighting power levels are based on Illuminating Engineering Society of
North America (IESNA) recommendations, which are industry standard practices that
have worldwide recognition. Note that outdoor lighting standards do not allow trade-
offs between interior lighting, HVAC, building envelope, or water heating energy con-
formance requirements.