Focusing on Lighting System Upgrades
Part 1 of a 3 part article on understanding facility needs and testing products for a lighting retrofit
Upgrades of lighting systems are one of the most effective ways that engineering and maintenance managers can improve energy efficiency in institutional and commercial facilities. As lighting manufacturers have introduced new light sources and fixtures while improving the efficiency of existing products, managers have a wider range of options than ever when implementing upgrade projects.
But some products perform better than others. Some system upgrades result in an annual energy savings of 20 percent, while others exceed 50 percent. Some go unnoticed by users, while others result in a large number of complaints concerning glare or the way the lights changed the appearance of objects within the space.
The differences among products often boils down to how closely managers examined their options prior to implementing the program. Too often, managers take the easy course and simply specify a one-for-one replacement of the existing fixtures with new, higher efficiency products they chose based on recommendations from a lighting manufacturer.
While this approach might reduce energy requirements, it does not take into consideration the lighting needs of the space, the way those needs might have changed over the years since the original system was installed, starting with characteristics for the lamp selected, and the impact glare or the color temperature of the light sources will have on the tasks being performed in the space.
One-for-one replacement cannot guarantee managers will get the most for their investment. The only way to guarantee the optimum return on the lighting-system investment while reducing the risks is through careful planning. It does not matter if the project is small and impacts only a limited area or if it is facilitywide and impacts tens of thousands of square feet of space. To succeed, managers must plan the upgrade.
The planning process
The first step in the planning process is to establish the program’s goals. The most commonly cited goal is reduced energy use by the lighting system. Lighting is a major energy component in buildings.
Reducing energy use is usually the driving force in upgrade programs, but it is not the only one. Proper selection of a replacement also can reduce maintenance requirements and costs by extending lamp life or simply making it easier to change lamps. Proper specification of new fixtures also can improve the quality of the light the system produces. All of these can and should be goals of the upgrade.
Next, managers need to weigh the options available to them in upgrade programs. Upgrading can and should involve more than just changing out the light sources. Some of the quickest paybacks for upgrades come from improving the control system. Occupancy sensors have been around for a long time and provide the quickest payback for areas with limited occupancy. Dimming systems can reduce energy use while allowing users to match the light output of the system to their particular needs, especially if those needs change over time.
Daylight harvesting systems are well-suited for applications with large window areas. These systems sense the total light level in the space and reduce the output and energy use of the lighting system when sufficient sunlight is available.
Centralized lighting controls allow the facility’s energy management system to ensure that lights are off when not needed based on the facility’s occupancy schedule. They also allow managers to turn off or reduce light output of select lighting systems during periods of peak energy use in order to limit electrical-demand charges.