It would be inconceivable to invest in a fleet of automobiles that are rated at 10 miles to the gallon when more fuel-efficient models are available. In effect, it is possible you are doing just that when replacing lights as they reach the end of their lives. Changes in the lighting industry, through advanced technology and government regulations, have made today's lighting products more efficient than past products. Substantial savings can be realized by retrofitting existing lights with new technology.
In addition to the economic benefits, there are other positive aspects of changing to the most efficient lighting systems available. Reducing the amount of electricity used directly affects the amount of pollution generated by power plants. A typical lighting retrofit in an 80,000-square-foot school will prevent 120 tons of carbon dioxide, 1,250 kilograms of sulfur dioxide and 400 kilograms of nitrous oxide from entering the atmosphere. These reductions are equivalent to planting 44 acres of trees per year, removing 25 automobiles from the road per year and saving 13,673 gallons of gasoline.
New products can improve aesthetics and reduce maintenance. New tri-phospher coatings in fluorescent lamps improve color rendering, which will make people, furnishings and the overall interior space look more appealing. Compact fluorescent lamps can replace incandescent lamps and have more than 10 times the lamp life. In addition, compact fluorescent lamps are manufactured to match the warm incandescent color. Light emitting diodes (LEDs), which have a 20-year life expectancy, can replace lamps in exit signs.
There are many good reasons to retrofit lights with the most efficient products available. The most prominent is the financial benefit. Lighting retrofits are the cornerstone of most performance-contracting projects. The dollars generated from a lighting retrofit can help fund other improvements that may not be as attractive as stand-alone projects. The overall concept is simple. The new efficient lighting systems save money on utility bills and in-house maintenance. The savings pay for improvements, and when the improvements have paid for themselves, the savings continue. A typical lighting retrofit will save 35 to 40 percent on the cost of operating the lights.
Drawbacks to a lighting retrofit project can be avoided by spending time at the front end of the project. There are a many manufacturers and products available, which can lead to specifying or accepting a bid that is based on unreliable equipment. With new evolving technologies, make sure to separate the sales hype from the facts, selecting proven reliable products. Look at the manufacturers as well as the products. While most manufacturers experience problems with products at some point, look for a company that stands behind its products, providing solutions to problems.
Making it work
There are a few basic steps to follow to ensure a successful project. The first is to compile an accurate audit of current lighting systems. Gather information on the types of lights and controls that exist and how many hours they operate. Measure and record present levels of illumination. Record type of luminaire, mounting arrangement, lamp/ballast type and wattage, voltage and type of control (switch, dimmer or circuit breaker). Note each area or room, identifying each system and its function.
A classroom may have general lighting with two-level switching, a separate light located at the chalkboard and task lights mounted above a counter. Consider each group as a subsystem within the area. Develop a form to be used in gathering information, which will help during the implementation process. One option is to install data loggers. A data logger is a small device that, when placed in a space, records the amount of time the lights are on and whether the space was occupied or unoccupied. This information helps in determining operating hours and whether or not to install occupancy sensors.
Be sure to involve the staff and students. Educate them in the process; tell them the benefits and improvements associated with the project. Listen to comments; this input can be valuable when determining the retrofit scenarios. Lighting is somewhat subjective and will not please everyone. However, by involving students and staff, the perception of the project and its benefits will improve.
The next step is to evaluate the information. Determine some of the basic parameters to be used in the calculations, such as hours of operation and cost of energy. Be realistic, if not a little conservative, in setting these parameters. Decide if you want to include soft cost savings in evaluations. The new lighting system may not need new lamps for three years, meaning less labor. Determine if that projection should be included in savings projections. Include all relevant costs associated with the project, such as disposal costs for spent lamps and ballasts. Some lamps and ballasts are considered to be hazardous waste and must be disposed of properly or recycled. Recycling lamps and ballasts adds only a small cost to the overall project.
Set goals to be used in judging the retrofit scenarios. These goals should include financial hurdles to be achieved and lighting-system performance constraints. Remember that the retrofit scenario that has the lowest first cost and shortest payback may not be the best option. Selecting a more expensive scenario with a longer payback may yield substantially more savings over the life span of the equipment. Match technologies that meet the financial and performance goals, and do sample installations. A sample installation may highlight a shortcoming of a particular product or design that was overlooked. Installing samples allows you to get comments from the users and maintenance staff, which may lead to changes in the retrofit scenarios.
When selecting retrofit scenarios, remember, most people do not think of the effects lighting can have on productivity and performance. There are many studies that prove quality lighting improves productivity and performance. Do not sacrifice quality illumination no matter how much energy is saved. The most common measurement for the performance of lighting systems is the amount of foot-candles provided.
The Illumination Engineering Society of North America (IES), the industry's governing body, has set standards to judge the performance of lighting systems. It says that, in addition to foot-candle levels, attention must be paid to visual comfort, indirect and direct glare, and uniformity ratios to provide a quality lighting system. The amount of illumination generated by a lighting system will decrease with time. While foot-candle levels may be matched with the retrofit, they may change a few years later. The occupants may not notice the difference, but it will show in reduced productivity and performance. Include depreciation factors in design calculations to compensate for the loss of light.
Spending time upfront
The amount of time spent gathering information to evaluate a project has a direct connection to the level of success. Successful projects require a fair amount of planning and information gathering. Spending time in the beginning will weed out technologies that do not fit the application and help to ensure a successful project.
The last step is implementation. Most lighting retrofits take place in occupied buildings; therefore, decide if the work must be completed after-hours to minimize disruption to normal activities. The contractor will need space to store new materials, and spent lamps and ballasts being held for pickup for recycling.
After the lighting systems have been retrofitted with the most efficient technologies, make sure the systems maintain efficiency with group relamping and regular cleaning.