Case study: Wireless lighting system achieves energy efficiency
California office building retrofit goes totally wireless
As part of the Los Angeles County 2020 energy efficiency measures, Dewberry’s design-build practice performed energy upgrades for an administration building in Van Nuys, Calif. A key change was upgrading all non-LED light fixtures to LED and upgrading the lighting controls to comply with California Title 24 throughout most of the facility. The design also included heating, ventilation and air conditioning replacements and electrical equipment replacements.
The facility posed a series of challenges, as the existing lighting had been upgraded once since the original 1960 construction and the controls were all manual wall switches. Walls were to remain untouched and many ceiling spaces were inaccessible while others were being replaced with a 2- x 2-foot lay-in ceiling. None of the spaces was networked together as the overall size of the facility did not require demand response controls.
Dewberry used wireless controls to meet the requirements of Title 24, even though many ceilings were being removed and replaced, allowing for a wired control system to be installed. While the upfront cost of the system equipment was approximately 20% to 30% more than a wired system, the labor savings of the wireless system made up for the material cost.
The main lobby is a high-volume space with exterior glazing. To make the space code-compliant, a daylight sensor and wall mount occupancy sensor were used for automated on/off and daylight harvesting controls. This allowed for the occupant to have manual on/off and raise/lower control of lights in the space as well as automatic daylight response control via the wireless sensor.
The restrooms all had hard, inaccessible ceilings and walls. Dewberry specified the a two-button radio frequency switch with ceiling-mounted vacancy sensor. This allowed the space to use the existing switch-leg wiring while adding ceiling-mounted occupancy sensing control without the need to install any additional control wires.
Open offices, corridors and service counter areas all used a two-by-four LED fixture with an integral one-touch occupancy and ambient light sensor. For occupant controls, a wireless wall switch was provided to allow for manual on/off and raise/lower controls.
The private offices also used a 2- x 4-foot LED fixture. Instead of the on-fixture sensors, the wall-mounted switch and sensor were provided for on/off, raise/lower controls within the space. The need to run additional dimming control wiring was eliminated by using wireless-enabled fixtures.
The use of wireless controls made the upgrade of the lighting controls from manual toggle switches to a fully Title 24-compliant installation a simple task.