Green Light

Schools and universities are building and operating their facilities more efficiently as they continually look for ways to reduce energy use. One of the easiest and most effective components of energy management is lighting control. Many schools can install lighting controls that significantly reduce unnecessary lighting usage.

At the root of the drive for energy efficiency is the concept of sustainability, or “green” building. This involves using environmentally benign building materials whenever possible, as well as renewable resources and energy-efficient technologies to operate and maintain facilities. The move to green has been propelled by a desire to save energy, especially as those costs continue to escalate. Embracing green design principles also can help schools attract students, particularly at higher-education institutions. A growing number of national and state programs can assist schools in establishing green practices.

Lighting-control technologies

Lighting controls can encompass dozens of different types of products, but basically there are three underlying technologies that provide automated control of building and exterior lighting. Occupancy-sensing technology works by detecting the presence or absence of occupants in a space and switching the lighting on or off as appropriate. Daylighting technology uses a photosensor to identify the level of natural light contribution; when this reaches a prescribed level, the control will adjust artificial lighting downward or off. Finally, scheduling-based technologies control lighting through programmed schedules. At specified times or when particular events occur, the control apparatus, usually a control panel, turns lighting on or off as desired.

No school is identical, but most have comparable spaces and lighting needs. For these spaces, lighting-control professionals can identify specific control strategies that will provide appropriate lighting and minimize unnecessary lighting.

Common spaces

For many classrooms, a combination of occupancy sensing and bi-level switching offers effective control and convenience. An occupancy sensor will turn lighting on when someone enters a classroom and turn it off when the room is vacated. Wall switches can override the sensor for specific situations, such as showing a film. Switches also enable bi-level control, in which an individual lamp in each fixture can be turned off to minimize energy usage without significantly affecting lighting levels. With this type of classroom application, typical savings can range from 30 to 40 percent.

School restrooms also benefit from occupancy-based control. In large school restrooms, the best practice includes installing a ceiling-mounted ultrasonic occupancy sensor. It can detect occupancy around partitions and other obstacles. An occupancy sensor also can control lighting and exhaust fan operation at the same time. The resulting savings can be as high as 40 percent.

Daylighting is an effective strategy for those areas with substantial natural light. This typically includes classrooms on building perimeters and administrative areas. In these rooms, a daylighting control can be added to basic occupancy-based control and bi-level switching. A photosensor will dim controlled lights when the daylight contribution reaches a specified level. When daylight diminishes, the sensor returns lighting to higher levels. This added level of control can increase energy savings by 10 to 30 percent.

In administrative areas, such as a large private office with abundant daylight, an effective control strategy combines the use of occupancy sensors and daylighting control.

Daylighting control also can enhance exterior lighting on a campus. For parking-lot and walkway lighting, an exterior photosensor will turn lighting on at dusk. A control panel can turn some lighting off at a specified time (perhaps 10 p.m., after scheduled activities have concluded for the day), while maintaining other lighting for security. Building-mounted security lighting around entries can turn on at dusk via a photosensor and remain on all night.

The best practice for other areas, such as hallways and gymnasiums, involves time-scheduled control. In hallways, lighting would turn on at a scheduled time in the morning and remain on throughout the school day. After school hours, scheduled control would be supplemented with occupancy-based control, so some of the hallway lighting could turn off when the area is vacant.

In many gymnasiums, an effective control strategy involves scheduling lighting to turn on at a specified time in the morning. Lighting would remain on until a specified time in the afternoon, when regularly scheduled activities have concluded. At that time, lighting turns off via the control panel. For later events, school workers can override the control panel and turn on lighting with keyed wall switches or electronic timer switches. After a specific amount of time, the panel can automatically turn lighting off.

Regardless of how a school is designed or operated, the first step toward “greening” the campus remains the same — making a commitment to reduce energy usage and to learn about the resources available for reaching this goal.

Maniccia is manager of market segment development at The Watt Stopper, Warwick, R.I. She is Lighting Certified (LC) and a member of Illuminating Engineering Society of North America (IESNA).

Green resources

As green principles have become more familiar to designers and builders, many resources have become available to provide guidance and assistance.

On the national level, Rebuild America, together with the Department of Energy, offers the EnergySmart Schools program (www.eere.energy.gov/energysmartschools, www.rebuild.org/sectors/k12.asp or www.rebuild.org/sectors/col_uni.asp). The Environmental Protection Agency offers the EnergyStar for Schools program (www.energystar.gov/index.cfm?c=k12_schools.bus_schoolsk12). These provide technical assistance to help define energy-management goals, benchmarking tools to help organizations maintain progress, and special certification for schools achieving substantial success.

Programs sponsored by private organizations include the U.S. Green Buildings Council's Leadership in Energy & Environmental Design (LEED) program (www.usgbc.org/LEED/LEED_main.asp), the Sustainable Buildings Industry Council's high-performance schools campaign (www.sbicouncil.org/workshops/schools.htm), and the Alliance to Save Energy's Green Schools Program (www.ase.org/greenschools/about.htm).

The LEED program provides a framework for assessing building performance and meeting sustainability goals. Nearly one-quarter of all registered LEED projects are in the educational sector. SBIC has developed a High Performance School Buildings campaign to generate interest among school officials in building high-performance, sustainable facilities. The Green Schools Program operated by Alliance to Save Energy combines conservation with curriculum development. It focuses on educating teachers, students, custodial staff and administrators about energy efficiency while establishing an energy-management program for school facilities.

School administrators also can tap into resources in individual states. The New York State Energy Research and Development Authority (www.nyserda.org/green.html) has offered technical assistance in drafting green-building standards as well as design assistance in developing energy-efficient building practices. In Massachusetts, the Green Schools Initiative (www.mtpc.org/RenewableEnergy/green_schools.htm) encourages districts to construct or renovate facilities that will cost less to operate and will provide healthier learning environments. The California-based Collaborative for High Performance Schools (www.chps.net) promotes energy efficiency by providing information, services, and incentives to school districts and designers. It also has a rating-based building and operation guide that specifies what a school must do to qualify for the high-performance classification.

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