Lighting, as noted by the U.S. Secretary of Energy, is still the low hanging fruit of energy savings. All four key components of a lighting system—lamps/light sources, luminaires (fixtures), ballasts and controls—are experiencing rapidly improving technologies, which building owners and facility maintenance personnel can use to their advantage to stop wasting lighting energy. Most American facilities still have old and outdated lighting systems, but even a well-maintained lighting system offers great opportunities for energy- and money-saving upgrades.
Assessing Facility Lighting Needs
People responsible for sustainability and facility engineering have a variety of resources they can call on to assess and audit their own specific applications and launch lighting retrofit projects. Professional lighting advice can be sourced from electrical contractors, energy-service companies, electrical distributors, lighting engineers, lighting designers, interior designers and others. The scope and type of a lighting renovation project should drive the decision about whom to use for professional advice. Rebates, incentives and support are widely available and project payback can be six to 12 months.
Today’s lighting systems and technologies are increasingly complex, but the reward is increased opportunity to save money. Knowing the right questions to ask and how to get started is key, and maintenance personnel can access a variety of tools. Facility personnel can refer to the IESNA Handbook for recommended light levels for various spaces based on the tasks performed within it. Spaces can be overlit or underlit, so it is best to understand light level targets for good lighting. Another source is the NEMA “Lighting Upgrade Checklist”. The Checklist guides non-lighting experts toward the best available lighting solutions.
Codes, Standards, Rebates
Maintenance personnel should be aware that the DOE has ruled states must review their energy codes by October and certify that these energy codes meet or exceed ASHRAE 90.1-2010. If 10 percent or more of a lighting power load is retrofitted, the space must meet the code requirements. It makes sense for any lighting renovation project, or new construction, to be designed to meet ASHRAE 90.1-2010 standards. The goal of ASHRAE 90.1-2010 is to improve building efficiency by 30 percent over the 2004 baseline.
To comply with ASHAE 90.1-2010, automatic control devices must be manual-on or automatic-on to not more than 50 percent of power. All spaces, except those with multi-scene control systems or 24-hour operation, require one of the following control methods:
- Scheduled auto shut-off for areas less than or equal to 25,000 square foot, based on time of day
- Occupancy sensors (maximum setting 30 minutes)
- Other control indicating space is unoccupied
In enclosed spaces, control with at least one control step between 30 and 70 percent of full power is mandated. Exceptions include corridors, public lobbies, restrooms, stairwells, storage rooms, and electrical/mechanical closets.
Rebates for LED luminaires are given by many utilities for DLC-qualified luminaires and retrofits that evaluate fixtures in a similar manner to Energy Star.
EPAct 2005 tax incentives are also still available through the end of 2013. If watts are lowered by 40 percent per square foot over ASHRAE 90.1-2001, there is a tax deduction of 60 cents per square foot or 30 cents per square foot for a 25 percent reduction.
Latest Lighting Technology
Energy and maintenance savings can be maximized by installing new, high-efficiency lamps, luminaires, ballasts and controls.
The market today offers many types of retrofit kits, including fluorescent and LED, where the existing housing is reused, and there is no need to disturb the ceiling plenum. Many retrofits deliver over 100 lumens per watt.
The field of lighting control is experiencing remarkable new technology, including wireless products that solve tough retrofit applications, and digital controls that offer flexibility and intelligence. Because the vast majority of existing buildings have no lighting controls of any kind installed, there is great opportunity to reduce lighting energy usage by installing occupancy sensors or other stand-alone controls. Wireless solutions provide good alternatives when construction obstacles exist, such as asbestos and hard cap ceilings, or when the cost of pulling new electrical wiring is prohibitive.
Performance Expectations
Management and engineering personnel should evaluate the criteria for lighting retrofit projects depending on the type of application.
Commercial and retail facilities: Pay special attention to the aesthetic appearance of a new lighting system because the human experience is crucial. In a retail environment, energy savings means nothing if customers stop shopping there. Extra weight should be given to glare control, proper beam distribution and the aesthetic appearance of the luminaires.
Offices: lighting controls can dramatically reduce operating costs. Time scheduling, task tuning, daylighting occupancy control, personal control and variable load shedding can reduce the energy consumption for lighting by 20 to 75 percent. Employee productivity can be increased by the quality of the lighting.
Industrial (warehouse and manufacturing) facilities: Emphasis should be put on energy savings because lighting operating expense is a key driver of business profitability. In warehouses, turn off lights, or reduce them to 50 percent, in unoccupied space. In manufacturing, well-designed lighting reduces manufacturing downtime and product returns because of undetected visual product defects.
Outdoor applications: Maintenance costs and serviceability of retrofit lighting projects are key because outdoor luminaires are often hard to access. New fluorescent, HID and LED solutions are on the market, so evaluate how long a retrofit lighting system will operate in between routine service requirements.