Save Time and Energy with Wireless Lighting Control Retrofits

Donlon Feature.jpgTo reduce energy use in existing buildings, few systems can have the same impact as lighting and lighting control retrofits. According to the U.S. Department of Energy, buildings consume 39 percent of the total U.S. primary energy. In commercial buildings, 28 percent of the energy use is devoted to lighting, which makes lighting an obvious target for gaining energy efficiencies.

There are a number of ways to reduce energy use but most involve sacrificing something in return. Lighting control strategies actually enrich the building environment by delivering both cost and energy savings while increasing occupant comfort and enhancing productivity. Additional savings can be realized by using wireless control to reduce installation costs and minimize the impact on occupants in the space.

Let’s first look at some simple lighting control strategies that are flexible, scalable, easy-to-install, and often offer payback times of just a few years. One quick tip – individual strategies, such as occupancy/vacancy sensing, can make significant contributions to energy savings by themselves, but the greatest value is realized by layering control strategies, which typically delivers lighting energy savings of up to 60 percent or more.

Each of these strategies can be implemented in conjunction with efficient new sources including a wide variety of LED lamps and fixtures. Be sure to work with a controls manufacturer that has tested many combinations of controls and sources and makes that compatibility information readily available to its customers. Ensuring compatibility between controls and light sources is critical to achieving expected dimming performance.

Digitally addressable fluorescent ballasts and LED drivers allow the lighting in the space to respond to automatic control strategies to achieve maximum lighting efficiencies. In many cases, dimming electric lights also reduces demand on HVAC systems, translating to even lower operating costs.

Basic lighting control strategies can be easily implemented in virtually any size space to deliver immediate lighting energy savings.

1. High-end tuning (sometimes called high-end trim) limits the maximum light output for each fixture, ensuring savings even when the lights are just turned on to “full.” High-end tuning can be implemented with either digital control strategies or by choosing a dimmer that allows the installer or end-user to manually reduce the maximum light level by 10-20 percent. This is an especially effective strategy for two reasons:

  • In many cases, lighting is designed to higher levels than necessary for the specific tasks in each area.
  • The human eye automatically compensates for reductions in ambient light. Dimming lights to 80 percent reduces energy use by about 20 percent while keeping light levels comfortable and creating a change that is virtually undetectable in the space.
2. Occupancy/vacancy sensing automatically turns lights off when a space is vacant. Additional energy savings is achieved by requiring the occupants to manually turn on the lights when they enter (vacancy sensing) or by having the lights turn on to a level less than 100 percent when the occupant enters (partial-on occupancy sensing). Vacancy-only sensors are available for areas where required by local or state code (like California’s Title 24).
 
3. Daylight harvesting automatically dims electric lights when enough daylight is present. To ensure maximum savings, daylight sensors communicate light levels to digitally addressable dimming ballasts so the light can be gradually and continuously adjusted to maintain the preferred lighting leve