Bright Ideas

Feb. 1, 1999
Lighting is a major component of educational institutions that often is taken for granted, except when it comes to energy bills. However, modern lighting

Lighting is a major component of educational institutions that often is taken for granted, except when it comes to energy bills. However, modern lighting technology and products can mean massive savings in energy costs for schools and universities.

Most educational facility managers consider energy costs a fixed expense, but investing in state-of-the-art electrotechnologies can reduce energy consumption and benefit the bottom line dramatically. In addition, utility rebates can shorten payback periods and enhance the return on investment (ROI). Lighting upgrades alone can result in an average payback period of 21/2 years, and an ROI of 40 percent.

According to the Department of Energy, lighting in institutional facilities, including schools and universities, can consume up to one-third of a building's total energy cost. Therefore, a sensible approach to any energy-savings program should begin with a lighting upgrade.

Lamps and ballasts Improving fixture efficiency is a common first step in lighting upgrades. A ballast and lamp upgrade can increase the efficiency of converting electricity to light. A common upgrade is the replacement of old T12 lamps and magnetic ballasts with T8 lamps and electronic ballasts.

When Nordonia High School, Macedonia, Ohio, made such an upgrade, it immediately realized a savings of $30,000 a year in energy costs, which could then be put directly into the classroom.

Switching out T12 lamps for energy-efficient T8 lamps is a relatively easy process since T8 lamps utilize the same medium bipin bases of the T12 lamps, meaning they fit the same sockets. Since T8 lamps operate on a reduced current, they must be matched with the appropriate ballasts.

Electronic ballasts can start T8 lamps in either rapid-start or instant-start mode. The instant-start mode produces more lumens per watt, meaning the lamp is more efficient, but the lamp life will be reduced if the system is switched on and off frequently. This lamp-life reduction may be as much as 25 percent at three hours per start, but is negligible at 12 hours or more per start.

Ballasts are another product making an inroad into saving money in terms of lighting. Fluorescent lamp ballasts give lamps the high-voltage startup the lamp requires when first turned on, and regulate the current when the lamp is on. Where older magnetic ballasts may require 16 watts to operate two 40-watt T12 lamps (96 watts total), electronic ballasts can operate the same fixture for a total of 72 watts, while losing a minimal amount of light output. Other advantages of electronic over magnetic ballasts include reduced weight, flicker, noise and heat output, and the capability of operating up to four lamps. A drawback to electronic ballasts for many schools and universities, though, is the initial purchase price-they can cost up to twice as much as standard magnetic ballasts.

However, the payback may well be worth the initial cost. For instance, during a two-phase retrofit program, El Paso Community College, Texas, installed more than 11,700 electronic ballasts on three campuses as a replacement for existing magnetic ballasts. Project payback of the $234,000 cost is calculated to be less than 21/2 years. The standard electronic ballasts were chosen due to their 33-percent energy savings compared to magnetic ballasts.

Compact fluorescents Administrators also should take a good look at the use of incandescent lighting with an eye to making replacements. Incandescent downlights ranging from 75 watts to 100 watts can be upgraded by installing compact fluorescent lights (CFLs) that use only 15 to 18 watts each for comparable illumination. In addition, CFLs save on maintenance costs, with a typical 10,000-hour lamp life, as opposed to the 1,000-hour rated life of incandescents. This makes it difficult to justify the continued use of incandescent lighting.

Besides using CFLs as downlights, they may be utilized as surface lights, pendant luminaires and floodlights. However, since CFLs are not as effective as incandescent lights in projecting light over distance, they may not be suitable in high-ceiling downlighting applications. In addition, they should not be used in situations that require dimming, since conventional dimming controls may pose a fire risk when used with CFLs.

The University of Washington, Seattle, discovered that upgrading from incandescent to CFLs can mean conserving a great deal of energy. The South Campus Center of the 173-acre university recently underwent a jointly funded university and utility conservation effort when Seattle City Lights was looking for ways to offset the growing need to add generating, and the university decided the 150-watt incandescent lamps no longer met the energy-efficiency needs of the growing campus community. The university replaced all 338 150-watt lamps in the center with new 38-watt fluorescent lamps. The upgrade reduced energy use more than 50 percent. Added to the utility rebate, the upgrade provided an ROI of less than one year.

Seeing signs Another lighting product making energy-saving inroads are exit signs. The garden-variety 24-watt to 40-watt incandescent exit sign, which can consume upwards of 350 kWh of electricity per year, is being replaced with signs utilizing 21/2-watt light-emitting diodes. Other alternatives include fluorescent lamps, low-wattage incandescent lamps, light-emitting diodes (LEDs), electroluminescent panels and radioluminescent tubes.

Improving luminaire efficiency through more efficient reflectors and shielding materials, along with a regular cleaning and inspection program, also can save a good deal of money in lighting expenditures. Reflector technology and correct reflector configuration designed to match task-specific requirements can eliminate unnecessary lamps and ballasts, resulting in a dramatic decrease in energy consumption.

Typically, specular reflectors are made with anodized aluminum, enhanced (or coated) anodized aluminum, and/or silver films comprising their mirror finish. During a delamping retrofit, two of the lamps and the ballast that controls them are removed from a four-lamp luminaire, and the reflector is installed. This can mean as much as a 50 percent reduction in energy usage.

Occu pancy sensors Controlling burning hours using automatic lighting controls saves energy and money, since reducing wattage represents only half of the potential for maximizing energy savings. Occupancy sensors are cost-effective devices that ensure lights are energized only when occupants are present. The two types of occupancy sensors most commonly used are:

-Infrared sensors, which detect the motion of a heat source, such as a person, with a segmented lens that divides the sensor's field into zones. However, small motions, such as a person typing, may not be picked up by the sensor.

-Ultrasonic sensors, which can sense relatively small movements through the emission of a high-frequency signal out of the range of human hearing. A distortion in the frequency of the returning signal caused by motion in the room is detected by the sensor, which then "knows" that the room is occupied. An adjustable time delay feature lets users control how long the lights will stay on after motion is detected.

The cost-savings capability of occupancy sensors was demonstrated by Des Moines Area Community College, which utilized an occupancy sensor specifically designed for classroom lighting control. The college installed 118 sensors, which covered 114 classrooms totaling 295,000 square feet. The upgrade, which included a retrofit of T8 lights and electronic ballasts, cost the college $23,800 in materials and labor, and resulted in an energy savings of $11,500 per year. Including the utility incentive rebate of $9,074 that the college received, the payback for the project was only 11/3 years.

The benefits of energy-efficient electrical products present an enormous opportunity for educational administrators, says Jack Briody, national chairman of the Energy Cost Savings Council (ECSC). In conjunction with government organizations such as the Department of Energy and the Environmental Protection Agency, ECSC is an organization of electrical manufacturers and interested industry groups that promotes energy conservation in schools and universities, as well as other commercial facilities.

"The idea the ECSC is trying to get across is that administrators who make an investment in lowering their electrical costs can realize a very significant return on investment (ROI)," says Briody. "We want everyone to learn about the new technologies available that can reduce energy consumption by 30 to 50 percent, with a payback often measured in only a year or two. Another plus is that even after the project has paid for itself, savings continue to accrue over the entire life of the new electrotechnology element, which averages 10 to 20 years."

For more information about ECSC, contact the group at (888)829-2209, or visit its website at

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