This CE Center article is no longer eligible for receiving credits.
Exceptional accomplishments are the expectation of schools across the country when budgeting for comprehensive school improvements. Stretching taxpayers' dollars is imperative as more and more school districts expect excellence in classroom design, durability, increased air quality, as well as environmental efficiency. New materials are providing innovative solutions for designers who want to assure quality buildings for the nation's children who spend almost 90 percent of their school day inside buildings.
The Council of Educational Facility Planners International (CEFPI) defines a healthy school as one that "cares for and looks after the overall well-being of its occupants."1 Healthy schools are environmentally friendly. They save energy and are designed to increase air quality. This article will focus on numerous products and materials that provide opportunities to deliver healthy schools for all communities.
These unique solutions span the gamut, including high-performance exterior walls, acoustics, roofing, fire safety, transparency, flexible spacing and even insulation that can transform smog and Volatile Organic Compounds (VOCs) to benefit air quality.
Hand-in-hand with many of these solutions is a desire for durability and permanence. To this point, Rich Thomas, LEED AP, marketing manager at Boral Roofing notes, "when budgeting for schools, longevity, ease of maintenance as well as a material's contribution to a healthy environment are all factors considered by school systems when planning their projects during this time of economic uncertainty."
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High-performance precast concrete walls enabled a faster construction schedule, as well as added to energy savings at Tilden Elementary School in Hamburg, PA.
Photo courtesy of High Concrete Group LLC; Designed by AEM Architects, Inc. |
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Innovative tiles that convert smog into fertilizer will protect air quality for new schools.
Photo courtesy of Boral Roofing |
Whether or not your project is part of a green rating system, such as the U.S. Green Building LEED® for Schools, the Association for the Advancement of Sustainability in Higher Education (AASHE), Sustainable Tracking Assessment & Rating System (STARS), or Collaborative for High Performance Schools (CHIPS), manufacturers are responding to the call for new products that help the environment without changing the project budget. As Mike Petersen, president of Petersen Aluminum states, "We assume that architects want to design responsibly whether or not it is a LEED® project. LEED® may have been the driver, but, it meant, for the entire industry, an improvement on whole product lines to meet solar cool roof criteria to save energy."
Brian Miller, managing director of business development at PCI, Precast/Prestressed Concrete Institute, also acknowledges this point, noting, "More designers are implementing designs that combine environmental performance with efficiency. They're realizing new ways for products to meet more than one design goal at a time."
The products and design solutions discussed in this article can be used to satisfy multiple design and performance criteria as part of an economic, environmental and social strategy for school projects.
Transforming Air Quality-Indoor and Outdoor Air Pollutants
Poor air quality and high levels of indoor and outdoor air pollutants have been linked to the increase in asthma cases in school-age children over the past 30 years.2 A few of the major culprits of poor air quality in schools are adhesives and other chemicals found in many building materials, as well as the use of harsh cleaning solvents. These products and many more building materials and common installation practices have high concentrations of VOCs, chemicals that evaporate into the air to become irritants, often causing headaches, dizziness and even sick building syndrome. Amy Lee, manager of marketing communications for CertainTeed Gypsum, notes, "With a focus on continuously improving the learning environment, sustainable building design is integral to the future of our schools. Recent advancements in building materials that improve indoor air quality and acoustics now provide more options for school design and construction."
According to the American Lung Association 2010 State of the Air Report, children face greater risks than adults from poor air quality because they are smaller and more active than adults. They cite a World Health Organization report that has documented the air effects on children to include short-term and long-term decreased lung function, worsening of asthma, increased incidence of cough and bronchitis and increased risk of upper and lower respiratory infections.3 Mold is also a contributing factor to poor indoor air quality. New products that address this air quality crisis include gypsum wallboards that capture VOCs and transform them into benign compounds, as well as smog-eating exterior roof tiles that turn pollution particles into fertilizer. In addition, manufacturers are making interior doors and wall panels that reduce VOC emissions.
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Analysis of chemical concentrations in residences, daycare centers and school buildings indicate that VOCs are the most prevalent pollutants. At the top of this list is formaldehyde, which may cause health concerns.
Illustration courtesy of CertainTeed Gypsum |
Walls: Cleaning Indoor Air
Engineered to capture formaldehyde, a new sustainable gypsum product converts this harmful chemical compound as it comes into contact with the board-by typical airflow movement-into an inert substance that is stored in the core of the board. A performance test of this wall system using ISO 16000-23 (indoor air evaluation performance test for evaluating the reduction of formaldehyde concentrations by absorptive building materials) demonstrated that within seven days, the formaldehyde concentrations in the air dropped to close to zero percent, permanently removing the VOCs circulating indoors. Walls that can clean the indoor air provide bonus environmental benefits.
According to the Gypsum Association, even though mold spores are everywhere, "gypsum board does not generate or support the growth of mold when it is properly transported, stored, handled, installed, and maintained."4 New technologies using treated paper enhances mold and moisture resistance to meet ASTM standard D3273, "Standard Test Method for Resistance to Growth of Mold on the Surface of Interior Coatings in an Environmental Chamber," achieving a score of 10, and an ASTM G21 score of zero for mold resistance, the highest ratings possible.
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Design professionals can reduce the wall thickness by 5/8" and still obtain good acoustic properties
Illustration courtesy of CertainTeed Gypsum |
In addition, new sustainable gypsum wallboards have enhanced acoustical properties. Design professionals who specify double-layer Type X wallboard in order to meet the necessary fire ratings in auditoriums, classrooms and hallways, may want to consider these new gypsum wallboards. Along with improving the acoustical environment, these Type X wallboards are moisture- and mold-resistant, abuse-resistant, and designed for fire-rated wall assemblies.
Indoor, for both air quality-improving gypsum boards and noise-reducing boards, these innovations also provide additional environmental benefits, containing as much as 99 percent total recycled content.
Roofs: Transforming Outdoor Air
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For centuries, architects have chosen tile roofs for aesthetics and durability. Today, with catalytic coatings, tile roofs can also enhance air quality.
Photo courtesy of Boral Roofing |
The development of photocatalytic coatings on tile and concrete roofs has delivered on the vision of self-cleaning buildings. This catalytic process was first introduced in Europe for road construction and medical facilities, and is now available in North America. These new roof tiles tend to promote a cleaner environment while turning "waste into food."5 One of the oldest roofing systems, concrete tiles, has new properties that make them able to mitigate air pollution. They can now be coated with a specially prepared catalyst that is embedded in the upper portion of the tile body. When exposed to sunlight, this catalyst speeds up the oxidation process, thereby resulting in the reduction of the formation of air pollution. Additionally this unique function destroys organic substances that come in contact with the tile surface such as mold, algae and moss.
The upper portions of the tiles are coated with a mineral crystal substance, similar to those used in toothpaste or sunscreen. When exposed to sunlight, this catalyst speeds up oxidization, and converts nitrogen oxide that is in the air from automobile pollution, into nitrogen. Working much like a catalytic converter does in a car, this roofing system transforms harmful substances into safe ones. The dirt, algae and moss neutralized by contact with the roof surface can be easily washed off the roof surface to fertilize the plants below.
Air pollution is an undisputed problem and the World Health Organization estimates 2.4 million people die annually of causes attributable to air pollution. Manufacturers estimate that 2,000 square feet of treated roofing tile can mitigate the same percentage of nitrogen oxide (a major component of smog) produced by one car driven just over 10,000 miles. Airborne pollutants are destroyed by the effect of sunlight on the catalyst and are rinsed off by rainfall or a garden hose. A study by the Fraunhofer Institute6 showed a significant decrease in air pollution when tiles were exposed to UV lighting. An additional benefit of a treated concrete tile is when installed on the roof it reabsorbs up to 20 percent of carbon dioxide emissions created during its manufacturing process.
Both concrete and clay roof tiles are made from materials with an inorganic surface and recycled content that withstand the harshest wind and weather conditions. They are durable and often are considered the most practical choice when calculating the lifecycle effectiveness of a construction material. Used on a school roofing system, they will reduce maintenance, as well as lower its smog footprint.
Maximizing Space-Flexible Solutions
Multipurpose Classrooms
Although the benefits of multitasking have been disputed, the benefit of multi-occupancy in schools of the future continues to be a goal for educators. Seeking a means to provide environmental support for teaching methods that allow for active participation, self-direction and the clustering of different interest groups, educators are asking professionals to design facilities that maximize their use throughout a busy school day. Multipurpose rooms, per se, are not a new innovation, but using movable high-performance glass walls provides a new means to enhance classroom facilities.
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One of many configurations used by Burleson Elementary teachers in Texas.
Photo courtesy of Nana Wall Systems, Inc. |
Case Study: Flex Space for Texas Schools |
When architects from SHW Group, Inc., of Dallas, Texas, met with the Texas Association of School Boards, they expressed interest in classroom flexibility for the new elementary schools being built in Texas independent school districts. At the direction of the Curriculum Director, SHW proposed an effective "flex space" concept that would give them maximum flexibility while reducing lab installation costs. Their challenge was to optimize and provide efficient use of limited floor space in schools, increase student learning and create a more enjoyable work experience for teachers.
This configuration (Diagram A) uses movable walls to either enlarge a classroom or provide for separation into small learning groups.
Illustration courtesy of Nana Wall Systems, Inc. |
Flex space was created in this school, by eliminating the common wall between two classrooms and installing two operable glass walls (see Diagram A). Configured in a V shape with a laboratory installation at the wide end, the space enclosed by the movable walls can be part of either or both classrooms. The teaching staff for the combined classroom can either monitor activities in all of the rooms or use the flex space to separate students for specific activities. They use this third space to provide alternatives in the classroom configurations. The walls have a horizontal mullion dividing the clear glass upper portion from the opaque, lower panel. When the pupils in the flex space are seated at their desks they are not distracted by the other activity in the other classrooms or by their classmates, yet the teacher can stand up and see both classrooms at once.
The principals, teachers and students at the new Texas schools all agreed on the effectiveness of flex space created by movable walls to enhance the learning environment. The school board appreciated the cost savings incurred by dual use of resources installed in the flex space. Architect Konrad Judd, AIA, defined his experience with a flex space system in the Burleson School District as a vision for the future of school design as a means to provide "education delivery into the 21st century with a more flexible learning model." |
Flexible classrooms allow for the design of smaller classroom buildings. Teachers can utilize them to engage in "response intervention" for behavior problems and as safe zones during school lockdowns with limited visibility from public corridors. They can provide a space for makeup exams and joint classroom projects. Educators and staff can monitor several classrooms at the same time. According to Ebrahim Nana, president of Nana Wall Systems, Inc., "Teachers have come up with over 100 ways to use flexible classrooms to enhance learning opportunities." When used in cafeterias, flexible spaces can provide many food-serving areas with one single clean-up area. For science or art configurations, central lab sinks, cabinetry and storage areas can save construction costs and reduce classroom footprints.
Here are some components that are important when planning a flexible classroom:
- Acoustic performance and sound-dampening qualities
- Swing doors as an option for easy access
- Visibility from adjacent classrooms by careful placement of glass panels
- White boards as an option for wall panels
In addition to interior configurations, new movable panels with higher energy performance values allow teachers to expand the learning environment outdoors (weather permitting).
Hallways, Fire Safety and Transparency
New products that open up classroom flexibility indoors and outdoors, in fact, can provide not only fire safety, but transparency along corridors or as part of new learning clusters. According to Jeff Griffiths, director of business development with SAFTI FIRST, as an increased measure of safety, design professionals are encouraged to "look at not just the fire rating of a system, but the ability of fire-resistant glass to stop the transmission of radiant heat from one area to another."
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Fire-resistive glass assemblies can create a sense of openness, add natural lighting, and increase the visibility to safe pathways.
Photo courtesy of SAFTI FIRST |
Fire-resistant safety glass is available for architects who want to design a school that meets fire codes without sacrificing visual continuity and transparency. Some newer fire-resistive glass is comprised of two pieces of tempered glass with an intumescent gel product in the middle. In a fire, the glass facing the fire will break as the temperature reaches about 400 to 500 °F. When the glass breaks, the gel solidifies and expands to create the equivalent of a fire-rated, masonry barrier wall.
Case Study: North Layton Junior High School, Layton, Utah |
AJC Architects of Salt Lake City, Utah, needed a solution for the renovation of the media center and new counseling center for North Layton Junior High School. They discovered that they could take advantage of a clear fire-rated glazing to keep the look of the media center and provide an open, welcoming entrance to the new counseling center.
Stringent fire-safety criteria were met in the corridor designs at North Layton Junior High School.
Photo courtesy of SAFTI FIRST |
"Prior to the renovation, masonry and non-rated hollow metal storefront and glazing were used in the building. Due to the increased square footage of the building, new fire-rated areas needed to be created," says Jodi Geroux, AIA, LEED AP of AJC Architects. "The existing hollow metal storefront glazing was located in walls that needed to be upgraded to 1- and 2-hour fire walls."
To achieve this, the design team chose a glass wall system that would meet the code requirements and maintain the building's original design, which incorporated a lot of glazing. They wanted a product with both an impact safety rating and a 2-hour fire rating that would meet ASTM E-119, the stringent wall criteria that limits the average glass surface temperature rise to 250 °F on the non-fire side. ASTM E-119 performance standards apply where fire ratings of 60 minutes or more are required in order to protect against dangerous radiant heat and provide a safe path of egress in the event of a fire.
Tested and approved in large sizes, fire-resistant glass can be combined with 60- to 120-minute aluminum-clad framing to provide wall-to-wall and floor-to-ceiling expanses of glass that provide beauty, elegance and maximum fire safety within a school's tight construction budget. |
Practice Makes Perfect
Measuring with Sound Transmission
Class (STC) Ratings
As defined in the ANSI Standard S12.60-2002, "Acoustical Performance Criteria, Design Requirements and Guidelines" for schools and summarized by the Acoustical Society of America,7 the amount of airborne sound blocked from transmission through a partition is measured in a Sound Transmission Class (STC) rating. The lower the STC rating, the greater the sound transmission through walls, adding to the background noise level in the space, degrading the ability to hear and understand speech. ANSI recommends an STC rating of STC-40 for music room doors. |
Permanent constructions, as well as portable, high-tech plug-ins for existing buildings are also part of the new school budget. Providing adequate rehearsal space for a school's musicians is difficult because of the numerous requirements for sound quality, sound isolation and privacy. Modular rehearsal studios, engineered as virtual acoustic environments, maximize rehearsal possibilities while minimizing the construction footprint. New music isolation rooms can be installed as part of new construction or renovation. The rooms range in size from approximately 4 ft. by 5 ft. up to 20 ft. by 25 ft. The height of these modular units ranges from 7 ft. 6 in. to 10 ft. high. The most common size selected by schools is approximately 9 ft. by 6 ft. (inside dimensions), which can house an upright piano, or up to a trio of instrumentalists. Ventilation, power and optional advanced electronics complete this "plug-in" performance module.
Units are constructed of thick metal walls and ceilings, both filled with high-grade acoustical insulation. Doors are made of steel with a fiberglass core and feature a glass window for easy monitoring and more inviting ambience. The wall panels are locked together with gaskets that seal the seams. Units are placed on floor rails and a pad that seals the floor to the floor of the existing enclosure. When placed in a row, sound transmission is almost inaudible, as each component in the modular unit meets stringent Sound Transmission Class (STC) ratings and Noise Isolation Class (NIC) ratings. Students who play a variety of instruments-from percussion to strings-can practice without distractions in side-by-side units or face-to-face units along the corridors of the school building.
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Optional recording equipment, speakers and digital signal processors allow the performer to "dial" their desired practice environment.
Photo courtesy of Wenger Corporation |
Standard 120v 60hz electrical outlets are provided in the rooms and the units are plugged into standard building outlets making it easy to install, particularly for existing building renovations. Unique to these new modular units are the performance capabilities embedded in the selected electronic packages. Optional recording equipment, speakers and digital signal processors allow the performer to "dial" their desired practice environment. With a push of a button, the room will provide the acoustical response of nine different venues-including recital hall, cathedral or large arena. Active acoustics technology helps musicians learn how to optimize their performance in different environments. Benefits include accelerated development of critical listening skills; improved articulation, dynamics and timing; and a more enjoyable practice session. In a busy school setting, it's often difficult for musicians to schedule rehearsal time in performance venues. These high-tech practice rooms can serve as surrogate performance spaces.
Furthermore, design professionals stymied by budget constraints can discover new products with superior acoustics to enhance learning while saving space. For example, "virtual acoustic environments allow the school to build small performance practice areas that provide large performance values," notes Stacy Hanson, marketing manager for Wenger Corporation.
Charting Performance-Safety, Durability and Environmental Targets
Smoke Prevention
Case Study: Toronto Four-Alarm Fire |
At 5:30 a.m., on October 29, 2010, a four-alarm fire broke out on the roof of York University's Toronto Track and Field Center. According to the National Post,8 there were "concerns that the propane tanks inside the building could explode." There were 36 fire trucks and 108 firefighters called to the scene, according to Captain David Eckerman from the Fire Prevention office, City of Toronto. The fire was confined to the roof and the first material to ignite was the exterior roof covering. Additional harm or injuries may have occurred if the roof insulation had not been made of a noncombustible material. Stone wool unlike other types of insulation does not ignite when exposed to flame or contribute to the spread of fire.
Roofing insulation stands up to an intense four-alarm fire at York University in Toronto, Canada. Noncombustible stone wool insulation prevented the fire from spreading, avoiding damage to property and possibly any human loss.
Photo courtesy of Courtesy of Roxul Inc. |
The roofing consultant on this project, Pinnacle Group Inc., is dedicated to environmental responsibility and has specified stone wool products for many years because of their combined benefits of durability, fire safety and insulation qualities. As Brandon Hexham, BA, RRO, GRP, vice-president of the company and roof consultant on this job stated, "Pinnacle Group Inc. strongly supports the use of stone wool insulation as part of a roofing system and we have specified stone wool on numerous projects over the past 10 to 15 years. On a recent project (a local university) where a fire broke out along the perimeter of the roof, it was the installed stone wool insulation that stopped the fire from spreading and destroying the entire roof and the building contents. The superior fire performance of this product saved the owner an immeasurable amount of money and damage to the building." |
Noncombustible, fire-resistant, energy-efficient stone wool roof insulation provides additional benefits for the prevention of fire. Unlike many other insulation materials, stone wool will not burn and will not release lethal toxic smoke, or cyanide gasses into the atmosphere when exposed to fire. The spread of toxic smoke in a fire can lead to more fatalities than those from the fire itself. According to Dave Lawlor of Roxul Inc., "When designing schools for children, we need to plan for safety, including noncombustible insulation that doesn't emit lethal toxic gases, such as cyanide, if there is a fire."
Roof performance includes many factors: longevity, warranties, insurance rates, energy efficiency but most importantly, fire safety. Most if not all accredited testing organizations in North America, measure the quantity of smoke developed during combustion and not the toxicity of the smoke itself.
One of the most widely accepted testing organizations for fire-resistance is FM Approvals. Roofing materials are classified by a number of test laboratories by class. Class 1 is the highest recognized standard, which includes testing for flame spread (ASTM E 108) and flame exposure below the roof deck. The FM 4470 NCC (noncombustible core) classification is an optional test targeting just the insulation component. It consists of three test methods, ASTM D 482 relating to ash content, ASTM E 2085 testing for flammability, and ISO 1716:2002 testing "heat of combustion" or energy released from the product. Most insulation products can meet the Class 1 standard, however stone wool insulation meets the more stringent testing methods of FM 4470 NCC (Noncombustible core) Rated Roof Insulation.
Stone wool has added material benefits as a non-directional fiber that is excellent for sound absorption. This product is mold and mildew resistant, and it is easy to install as well as maintain. It is used as an integral component for the excellent acoustic performance of interior and exterior walls and roof systems. Stone wool has been successfully used as an insulation solution for institutions along highways and near airports to reduce sound transmission.
This material has dimensional stability and maintains its R-value over time, unlike insulation that degrades, shrinks, or prematurely oxidizes as will some foam insulation products. Thermal resistance values range from 3.5 to 4.2 hr.ft2.F/Btu as measured at 75 °F according to ASTM C 518 (C 177). It will often outlast the membranes that cover it and provide the longevity that institutional buildings require.
Stone wool products are a sustainable solution, having a high-recycled content, reusability, and can even be recycled where facilities exist. This insulation is made from natural stone and steel slag. This slag is a manufacturing by-product of the steel industry, which is used as a raw material in the stone wool manufacturing process. Some stone wool manufacturing facilities have been able to recycle all of their production waste materials back into the manufacturing process, creating a zero-waste-to-landfill strategy; making both environmental and economic sense.
In addition, a lifecycle analysis of stone wool shows that the energy it costs to make this insulation will pay back that energy and CO2 used in its manufacturing within four to five months of service.
Cool Roofs with Cool Colors and Building Integrated PV Panels
One of the simple strategies for reducing the solar gain on a roof system includes the installation of a cool roof. Cool roofs reflect solar visible, ultraviolet and infrared rays as well as have a property of high thermal emittance-the ability to radiate absorbed, non-reflected solar energy. The U.S. Environmental Protection Agency (EPA) estimates that Americans spend about $40 billion annually to air-condition buildings.9 An innovation to this energy saving strategy is the removal of one of the obstacles for the application of cool roof specifications. Designers have resisted choosing cool roofs because of the limited roof color palette that met a design professional's aesthetics or project budget.
Cool roofs that are ENERGY STAR-qualified reflect more of the sun's rays and are estimated to lower the roof surface temperature by up to 100 °F, decreasing the amount of heat transferred into buildings and lowering the cost of air-conditioning. According to ENERGY STAR, qualified roof products can help reduce peak cooling demand by 10 to 15 percent.10 The ENERGY STAR cool roof project includes research by The Oak Ridge National Laboratory, as well as partnerships with roofing manufacturers who agree to continue testing for certification of their products.
ENERGY STAR metal roofs must meet tests that include the ASTM C1371 - 04a Standard Test Method for Determination of Emittance of Materials Near Room Temperature Using Portable Emissometers and ASTM C1549 - 09 Standard Test Method for Determination of Solar Reflectance Near Ambient Temperature Using a Portable Solar Reflectometer. Variegated roof products may also be rated according to the Cool Roof Rating Council (CRRC) Test Method #1.
Metal ENERGY STAR cool roofs have performance requirements based on the slope of the roof. Solar reflectance is a measurement from 0 (no reflectance) to 100 (highly reflectant). The initial Solar Reflectance Index (SRI) of a low-slope roof (less than a 2:12 pitch) is greater than or equal to 0.65 and after three years, greater than or equal to 0.50. The initial SRI of a steep roof must be greater than or equal to 0.25 or greater than or equal to 0.15 after three years. Partners in the ENERGY STAR program must offer warranties equal to those of their products that may not have these characteristics. Emissivity is a measurement between 0 percent and 1 (100 percent). An ongoing discussion among professionals and scientists is whether a highly emissive roof is better in cold cloudy climates. ENERGY STAR does not require minimum emissivity values for roofing products.
Up to recently, most cool roofs were white or a light color compromising many designs that required darker or broader color palettes. New infrared-reflective pigments have been developed for metal roofs that allow even dark colors, to achieve higher reflectivity values. Architects can choose from broad color palettes of ENERGY STAR colors to meet the requirements set forth by rating systems to reduce the heat island effect. Dark bronze, greens, colonial reds, browns, deep charcoal roofs are among a variety of color choices provided to the designer with high solar reflectance values.
New cool metal roofs also offer a platform for the integration of solar power. Building integrated photovoltaics (BIPV) are innovative thin-film laminates that can be applied directly to metal roofing panels. This factory-installed system is part of the roof finish; they require no penetrations through the roofing at the construction site. The metal standing seam roof locks together in panels that are attached to the roof by channels.
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Standing seam metal roofs bring new aesthetics to school designs.
Photo courtesy of Petersen Aluminum Corporation |
Accessible Entries that Control HVAC Cost
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Providing wheelchair accessibility through a swing door requires knowing act activation.
Photo courtesy of Horton Automatics |
According to Ron Grabowski, marketing product manager of Horton Automatics, "Increased focus on handicap accessibility, energy savings and student safety has driven the adoption of automatic means for entrance operations in school facilities."
Particularly on college campuses, demand for student safety and accessibility is a 24/7 requirement. Budget cuts that have reduced maintenance and security staff have created opportunities for new design solutions. Electronic access control systems such as card readers have become popular additions to new door installations.
Automatic swinging, sliding, and revolving doors must meet the American Disabilities Act (ADA) and the American National Standards Institute (ANSI) requirements to provide safe access to building occupants. Automatic doors are typically part of a vestibule design to reduce heat transfer to and from the building. Swing and slide door systems are routinely synchronized so that one will open after the other one has closed. Often architects and designers combine swinging, sliding and/or revolving doors in an entrance to enhance aesthetics and optimize energy efficiency. In this arrangement, the second set of swinging or sliding doors will not open until the first set has closed, completing the air lock in both cold and hot climates.
Case Study: Energy-Saving Automatic Revolving Doors |
Automatic and manual revolving doors have increased environmental benefits. In 2006, Massachusetts Institute of Technology (MIT) students studied the value of energy loss using swinging doors versus revolving doors.11 These students, members of a sustainability planning class, were curious about the use or lack of use of revolving doors on campus.
The students wanted to know why users were less likely to use a revolving door and more often opted for the adjacent low energy or standard swing door. A revolving door reduces air leakage because its curved design provides an air lock, effectively acting as a small vestibule. Due to this curved design, revolving doors are excellent entrance and exit systems for controlling heat transfer between the interior and exterior of a facility. Swing doors are used next to revolving doors because swing doors are required within 10 feet of a revolving door as required by the National Fire Protection Association 101 Life Safety Code.
The MIT students measured the air leakage between the use of revolving and swinging doors. They calculated that to heat and cool the annual air leakage through a typical entrance (both swinging and revolving combined) was 98,912.8 kilowatt-hours (kWhs) of energy. That energy is enough to heat 6.5 single-family houses for one year, or to light a 100 Watt bulb for 37.8 years. To generate that much energy, 18.8 tons of CO2 is emitted. They calculated that by increasing the use of revolving doors from 50 to 100 percent, MIT could save from 14.5 percent to 74.5 percent of the energy costs from a given door leaks and from 3 to 14.6 tons of CO2.
During the research, the majority of users responded that swing doors were easier and faster to use and the manual revolving doors were harder to push and often locked. However, when told that there could be as much as a 50 percent energy savings increase for MIT by using the manual revolving doors, more students said that they would use the revolving door if signs were added with this information.
The final results of this study included recommending additional educational signage at the swinging doors and the automation of the revolving doors.
In 2009, students began a "Resolve to Revolve" campaign as part of a sustainability MIT initiative. |
An important facet of using Low-energy/ADA-compliant swing door operators for entrances and vestibules is ensuring that architects and specification writers apply them to the appropriate MasterFormatâ„¢ sections. At times, these types of swing doors are specified in sections 08 06 71 or 08 71 00 "Door Hardware Schedule/Door Hardware" rather than the correct sections of 08 42 29.33 or 08 71 13 "Swinging Automatic Entrances/Automatic Door Operators." Why is this critical? Doors specified in the appropriate sections ensure that:
- An independent, certified professional installer trained through the American Association of Automatic Door Manufacturers (AAADM) completes the installation
- ANSI standards for opening and closing of doors are followed, reducing risk and liability
- Automatic operators are properly calibrated and meet applicable codes for mode of operation
- Operators are paired correctly with the doors and associated hardware
- Product and labor warranties are backed by qualified professionals
Thermal Mass Serving Multiple Functions
Along with energy efficiency, speed of construction, durability and prefabrication, materials that are high in recycled content, are important attributes for school buildings. Designers can use one material system to solve multiple aspects of the building design. Precast concrete sandwich wall panel systems are being left exposed to serve as the interior wall finish, as well as exterior envelopes. Precast walls are both structural and aesthetic, and can be finished with a variety of colors, textures, or veneer materials.
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Precast concrete can be quickly erected even in the winter, as shown in construction photo of Willow Creek Elementary School in Fleetwood, Pennsylvania.
Photo courtesy of High Concrete Group LLC; Designed by AEM Architects Inc. |
Concrete walls can also have integral colorants (pigments) applied to the mix, creating a consistent wall surface color even through renovations. Concrete is hard to scratch or nick and products are available to seal these durable wall surfaces. Manufactured off-site, these wall panels can contain continuous insulation and can be designed to meet performance values for acoustic design. When used as an interior wall with lighter-colored finishes, its reflectance can lower interior lighting costs. Concrete has low to negligible VOCs, improving indoor air quality, and it can contain recycled content and is recyclable.
Precast building walls and floors allow a design professional to take advantage of thermal mass as a design strategy. Due to its density, concrete has the capacity to absorb and store large quantities of heat, and then release it back into the building as the interior temperature decreases, contributing to a high-performance building envelope. The thermal mass effect reduces peak heating and cooling loads and delays the time at which these loads occur. The resulting savings can be significant-up to 30 percent of heating and cooling costs. Designers must understand the overall envelope system in order to optimize the benefits of using thermal mass. ASHRAE Standard 90.1 allows design professionals to lower minimum insulation R-values and provides higher maximum wall U-factors as a result of the properties of these wall assemblies.
Precast concrete is a durable, long-lasting material that is noncombustible, providing natural fire control, and resistant to wind, hurricanes and floods. It is nonorganic and cannot support mold growth. Precast concrete can be quickly erected, allowing the building to be enclosed faster. Manufactured in controlled factories, finish quality and high insulation properties can be guaranteed. Precast concrete reduces life cycle costs and with strengths of 6,000 to 7,000 pounds per square inch, it's an extremely durable building material.
Strategies for Innovative Designs
Tony Cortese is the president of Second Nature, co-organizer and leader of the American College & University Presidents Climate Commitment, co-founder of the Association for the Advancement of Sustainability in Higher Education (AASHE), as well as a consultant on institutionalizing sustainability principles and programs. In October 2010, he spoke to a group of educators and students at the national Bioneers Conference. In his speech he framed a call to action by educators as well as students to continue to educate their facility managers and administrators to change the way they are building and managing their facilities. The commitments to good environmental practices by educators are growing and the AASHE Climate Action Planning Wiki references numerous organizations, as well as rating systems that provide strategies for greening campuses.12 Many of these innovative solutions will assist the design professional in meeting AASHE targets.
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Tile roofing chosen at Stanford University in California, not only for permanence, durability and historic
authenticity, but also for enhanced air quality
Photo courtesy of Boral Roofing |
Conclusion
Whether designing a new school or renovating an old one, there are new, innovative products that save time, money and the environment. Manufacturers continue to develop new technology, methods of construction and responses to environmental stewardship. Designers work on innovations that will help educators resolve to meet the challenge of the 21st century school.
Architect Celeste Allen Novak, AIA, LEED AP, specializes in sustainable design and planning in Ann Arbor, Michigan.
