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8 Lighting Guidelines to Save Schools Money
Each year, California schools spend approximately as much money on energy – $700 million – as they do on books and supplies.1 Education spending is a frequent point of debate among politicians and citizens, and maximizing the implementation of energy efficient technologies in school facilities could act as a way to increase education budgets without allocating additional public funds.
With that in mind, California K-12 school districts are in the process of updating and retrofitting the mechanical and engineering systems in their schools, primarily through the implementation of Proposition 39. Improving the efficiency of school lighting is a priority in the effort to increase the energy efficiency of school facilities, due to its relative simplicity in comparison to retrofitting complex mechanical systems. Additionally, it is a great time for school administrators to upgrade their lighting systems and take advantage of the local utility incentives available for them to do so.
Proposition 39 and its impact on California schools
California's Prop 39, also known as the California Clean Energy Jobs Act, provides the state's public schools with up to $500 million a year for energy efficiency upgrades and clean energy systems. School administrators can apply for Prop 39 funds by submitting the Prop 39 data authorization form to the California Energy Commission (CEC) and to each of their utility providers. The form authorizes utilities to release school energy consumption data directly to the CEC.2 With Pacific Gas & Electric Company's (PG&E) help, school districts, including the Clovis Unified School District in California's Central Valley, have already taken advantage of these funds to reduce the amount of money spent on energy.3
By instituting some or all of the following eight school lighting technologies and strategies, administrators can realize a significant reduction in their lighting energy costs while also creating a more comfortable environment for their students, teachers and staff.
Audit current lighting energy consumption
The first step to improving school lighting energy efficiency is to understand how the lighting is currently used, determine what technologies and products are ready for replacement, and then evaluate the energy efficient replacement options. Conduct an audit, prioritize potential retrofits and conduct a life cycle analysis of the top choices to determine what will maximize the investment over the life of the product. As a reminder, if a school is seeking Prop 39 funding for a project, it's required to use the CEC's calculation tools. Audit assistance is available through the Prop 39 program, if needed.4
Remember to look beyond lamps and luminaires, and include lighting controls in the audit. Audit for applications where lighting is left on when the space is not in use. If needed, check out occupancy logging equipment from PG&E's tool lending library and measure the use of example spaces, then apply your findings system-wide.
Review lighting quality criteria and update design standards for the facility or district based on current lighting product features
There are many factors to consider when creating a design standard for illumination. The American National Standard Practice on Lighting for Educational Facilities (ANSI/IES RP-3-13) released by the Illuminating Engineering Society offers many criteria to consider. The following topics should be included when developing lighting specifications.
- Dimmability – Significant additional energy savings and improved staff satisfaction with new systems can be realized by offering dimming lamps and luminaires throughout school facilities.
- Correlated color temperature (CCT) – CCT indicates the warmth or coolness of the light emitted by a given source, typically ranging from warm white (2700K) to cool white (5000K or higher). Set design criteria so that the CCT is appropriate for the application and consistent across the facility or district. If desired, recent advancements in lighting-emitting diode product design now allow for variable CCT that can be changed according to teacher preference or time of day.
- Color rendering index (CRI) – The color rendering index is the current industry standard for measuring how accurately a light source renders the colors of the objects it illuminates. The maximum CRI value is 100. Light sources with a CRI of 90 or higher provide even better color rendering. Older fluorescent lamps are typically 80 CRI. In color-critical learning environments, specify lighting products that offer a CRI of 90 or higher. Higher CRI choices are now more widely available in LED products without added cost.
Replace older T8 fluorescent systems with higher efficacy lighting choices that have dimming capability
Select a product with a high lumens-to-watt ratio (efficacy), minimal glare and a distribution pattern that delivers ample illumination to the intended areas. Not all products are equal in quality. Become familiar with the illumination criteria needed to evaluate products per application type and make an informed decision. One option is making the switch from fluorescent to LED, which can reduce energy use by 50% or more.5
Opt for integrated LED luminaires rather than just changing light bulbs
LED luminaires that do not contain a replaceable lamp are designed to perform in an optimized way for a longer time. Reduce maintenance costs by upgrading to a dedicated LED luminaire rather than just replacing lamps. Additionally, the optical systems of dedicated LED luminaires and retrofit kits often provide improved light distribution and lighting uniformity as compared to using LED replacement lamps in an existing luminaire that was designed for use with a different technology.
If replacement lamps are the only option, evaluate, demonstrate and then decide
Before making a decision and purchasing a large number of replacement lamps, request or purchase samples and test replacement lamps with all ballast types used in the facility or district.
Be sure to test products labeled as dimmable with the installed dimming system if no upgrade to the controls is planned. For example, not all LED lamps will perform well when paired with older controls. The current expectation is that LED products should dim to 10% with no visible flicker when paired with compatible controls.
Install occupancy and scheduling controls in all intermittently occupied school areas, including outdoor applications
Classrooms, storage areas, locker rooms, gymnasiums, stairwells, indoor corridors, restrooms, outdoor building surfaces (canopies and wall packs), parking areas and other learning spaces waste energy when lights are left on during times of little or no occupancy. Installing occupancy sensors and schedule controls that dim or turn off the lighting when not needed can nearly eliminate unnecessary lighting energy usage.
Occupancy sensors can be added as stand-alone devices to existing lighting systems and are available in hardwired or wireless retrofit packages. Some wireless systems can be installed in minutes, with little to no wiring alterations other than changing the wall switch and adding sensors.
Additionally, some luminaire manufacturers now offer options to order luminaires with occupancy and daylighting sensors integrated into the product, eliminating the need for the design of an external controls system.
Implement automatic daylighting controls
Automatic daylight harvesting controls can reduce energy use and lower peak demand. Install photocontrols in all side-lit and sky-lit zones and connect controls to dimmable luminaires to minimize the visible change during dimming transitions. ON/OFF switching or step-dimming may be distracting to students and staff.
Install shading or films on windows and skylights to avoid direct sunlight
Shading and films minimize glare and unwanted heat gain by providing control over the amount of daylight admitted into a space. Manual or automatic shades also give teachers the ability to further control the daylight in their classrooms.
To monitor and measure the performance of the new lighting and controls systems over time, consider a networked lighting control system with energy monitoring features or sub-metering of lighting circuits. These options are typically a more expensive initial investment, but will assist with future retro-commissioning projects and help to determine whether the investment is performing as expected.
Improving lighting energy efficiency in schools and reducing the amount of resources spent on lighting energy use can be simplified by working with a qualified lighting contractor that has a proven track record with installing modern lighting systems and controls. For more information on finding and working with a lighting contractor, reference "The Complete Guide to Working with a Lighting or HVAC Contractor" eBook from PG&E. As another resource, the California Advanced Lighting Controls Training Program (CALCTP), is a statewide initiative aimed at increasing the use of lighting controls in commercial buildings. Visit www.calctp.org to obtain a list of contractors certified to work on projects that include lighting controls.
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