May-June 2011

From: Glow Industry

Avoiding Mistakes

Lighting can represent almost 40% of a commercial facility’s energy costs, and that a retrofit can reap a payback of less than three years. If a retrofit is done properly, it can increase productivity, reduce defect rates, and represent a cost advantage against competitors who haven’t implemented their own efficiency programs.

Best practices include:

• Pick the right vendor by checking references, testing recommendations against proposals, visiting past installations, and checking the company’s financial stability.
• Consider the latest Illuminating Engineering Society (IESNA) light level recommendations as a part of the review. The organization provides guidelines that factor the difficulty level of tasks being performed as well as the age of the work force.
• Retrofit from lower color-rendering (CRI) lamps to higher CRI lamps to improve visibility—even with lower light levels.
• Involve all key stakeholders up front, by addressing costs with the financing and purchasing team and employee productivity and maintenance with the operations team.
• Conduct a facility audit. A comprehensive audit involves a collection of area by area counts of all existing light fixtures, reviews light level readings, identifies obstructions, checks hours of operation, and reviews the tasks being performed within the area to make sure that the design selections will be correct for the environment.
• Controls, specifically occupancy sensors, are a critical part of a retrofit. Controls are becoming increasingly legislated and incented for via ASHRAE 90.1, Energy Policy Act of 2005, and utility rebate programs.
• Prior to choosing sensors for the facility, consider installing “light loggers” that track occupancy in target areas to get a sense of the savings opportunity. When choosing occupancy sensors, make sure the supplier provides “program start” ballasted luminaries rather than “instant start” to ensure no loss of lamp life from frequent on/off cycles. Additionally, make sure time and sensitivity levels are set properly upon installation.
• Proceed cautiously when using average kilowatt-hour charges in savings studies. Utility companies vary widely in how they bill and awareness of how demand and usage charges are being applied is critical for an accurate evaluation. Make sure to factor in demand charges, taxes, and seasonal peak charges to calculate costs and how they are applied.
• Consider a utility that charges a demand charge based on the highest usage of electricity for a month. If occupancy sensors are being used, are the lights going to be on when the demand charge hits? If so, the only savings captured will be the kilowatt-hour usage and not the associated demand savings otherwise expected. 
• Ask the project partner to check for the most up-to-date government and utility incentives.
• Not all lighting components work well together. Environmental conditions in a facility—such as temperatures in a factory or occupancy levels in an office space—can affect system performance over time. Those in factories with temperatures at mounting height levels in excess of 55°C (131°F) should ask suppliers about the availability of “high-ambient” approved fixtures and ask for warranties. Fixtures that run cooler sometimes last up to twice as long.
• Evaluate proposals carefully. Some vendors will propose simple lamp and ballast retrofits, which may offer good cost savings, but don’t encompass additional wattage reduction. Some suppliers will have dramatically lower fixture replacement counts in a retrofit project rather than replacing one fixture with another more efficient one. Fixtures can only be spaced so far apart before shadows, and poor light levels impact worker productivity and increase the risk of accidents, especially around machinery.
• In evaluating suppliers, check the products and associated warranties being specified. Do they have the reputation and financial wherewithal to correct any problems that may occur?
• When deciding on a new lighting system, consider the opportunity to reduce the number of lamp and ballast types that have to be inventoried while selecting longer life component technologies that will extend maintenance intervals. Additionally, check sample fixtures to see if access to the ballast compartment is tool-less to shorten the maintenance team’s time on the ladder. For open-air industrial fixtures that will be mounted in caustic or high ambient environments, check to make sure that the components specified will be able to operate at optimal levels.
• Validate projected results by testing the proposed retrofit system in a typical area. While it’s easy to measure before and after light levels as well as amperage reductions on tested circuits, the initial light levels on the test may not represent what will happen in the long haul. New lighting systems inherently provide more light than aged systems. Dirt depreciation and lamp degradation curves all need to be considered when evaluating a retrofit lighting systems performance over time. Ensure the supplier builds these maintenance factors into the proposed system evaluation so light levels meet long-term expectations.