Design Guide: How to Save 50% on Energy in School Buildings
A new guide written directly for the people who design, construct and manage school buildings offers step-by-step recommendations to halve energy costs without commissioning costly, time-consuming energy analysis.
The guide recommends a variety of energy-saving practices and equipment, including energy-efficient lighting.
ASHRAE’s Advanced Energy Design Guide for K-12 School Buildings
On Oct. 12, 2011, the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) released its “Advanced Energy Design Guide for K-12 School Buildings” to offer best practices for architects, design engineers, energy modelers, general contractors, facility managers and building operations staff. Developed in concert with the Department of Energy and three Alliance Associates – the U.S. Green Building Council, the Illuminating Engineering Society and the American Institute of Architects – the school guide is the second in a series of guides on achieving 50% energy savings in various building types. These recommendations go further than the minimum code requirements of ASHRAE Standard 90.1-2004.
Highly informative and very specific, “K-12 School Buildings: 50%” – which ASHRAE calls the guide for short – is divided into chapters aimed at different specialties. By speaking directly to building professionals, the guide promotes lower construction costs, faster payback and reduced operating costs without the need for planners to spend the time and money commissioning detailed energy models and analysis.
ASHRAE developed “K-12 School Buildings: 50%” because schools spend a lot of money on energy. In 2009 alone, the roughly 125,000 public and private K-12 schools in the United States used a whopping $12 billion on energy, according to the Department of Energy.
Lighting uses a particularly large amount of energy. In fact, lighting accounts for 30% of schools’ energy bills. ASHRAE’s guide offers a section on lighting that is written especially for design professionals and lighting engineers, and which is also useful for any professional interested in the latest advances in school design and energy-efficient lighting techniques.
Good Design Practices & Lighting Choices
The guide’s tips for slashing energy waste from lighting include:
- Daylighting: The guide calls for natural daylight in school spaces such as classrooms, resource rooms, gymnasiums, multipurpose rooms, cafeterias, media centers and offices. Because occupants can obstruct daylight by not pulling up the shades in the morning after pulling them down in the evening, the guide suggests educating occupants about the importance of sunlight.
- Interior Finishes: To enhance lighting efficiency, the guide recommends at least 80% reflectance for ceilings, 50% for walls and 20% for floors.Consistent Color Temperature: Schools often use a variety of light bulbs with different hues. The guide recommends consistency in light bulb color temperature and notes that 5000K bulbs offer the best visual acuity.
- Specific Lighting for Specific Purposes:
- General Lighting: Use linear fluorescent lamps (T8 high-performance lamp) and ballasts.
- Utility Lighting, Downlighting & Wall Washing: Use CFLs.
- Large Spaces & Outdoors: Use metal halide lamps.
- AV: Select lighting for maximum screen contrast while classrooms are dimmed for video or overhead projectors.
- White Boards: Maximize lighting on teaching surfaces, especially boards at the front of the classroom, to draw in students’ attention.
- Occupancy Sensors: As required in Standard 90.1-2010, the guide recommends occupancy sensors to turn lights on and off automatically in a variety of school spaces: classrooms, restrooms, locker rooms, offices, training rooms, copy rooms, conference and meeting rooms, employee lunch and break rooms, and storage and supply rooms.
Efficient schools provide enhanced learning environments. As the guide states: “An environment that includes appropriate lighting, sound, temperature, humidity, cleanliness, color and air quality can help students learn better. In many cases, improving these attributes can also reduce energy use.”
The Alliance agrees. In fact, the Alliance’s Green Schools program encourages energy efficiency in school buildings and promotes energy-efficient practices among students.
“The school building can be a learning lab for students. If that building is energy-efficient, students experience how their school saves energy. With education programs like Green Schools, those students also become advocates for energy efficiency in their homes and communities,” said Green Schools Program Manager Megan Campion.
Get the Guide
The report is available to download for free from the ASHRAE website (after you register for Advanced Energy Design Guides, ASHRAE provides links for a variety of guides including “K-12 School Buildings: 50%”). A print edition is available for purchase.
Although “K-12 School Buildings: 50%” is for new construction, its suggested technologies and schematics apply to other projects, as well as similar situations in commercial settings.