Designing efficient K-12 schools
Maxwell Chien, PE, LEED AP BD+C, Associate, Kohler Ronan, New York City
Chuck Dale-Derks, PE, LEED AP, Principal, McClure Engineering, St. Louis
Evan J. Hammersmith, PE, LEED AP BD+C, CGD, Associate, Mechanical, Karpinski Engineering, Cleveland
Michael Lentz, PE, CPD, HFDP, Director of Operations, Baltimore Office, Setty, Baltimore
Rodney Oathout, PE, LEED AP, CEM, Principal | Energy + Engineering Leader, DLR Group, Overland Park, Kan.
Michael Rader, PE, CEM, Vice President and Chief Operating Officer, Barton Associates Inc., York, Pa.
CSE: What’s the biggest engineering trend you see today in K-12 schools?
Maxwell Chien: Inclusion of a main distribution frame (MDF) or an intermediate distribution frame (IDF) closet to support information technology/audio-video (IT/AV) infrastructure. Increasingly, we are seeing schools providing advanced IT/AV planning to support the need for integrated AV systems for teaching and networking equipment for communication. These closets require additional year-round cooling that can sometimes, depending on load, be demanding. We also see a lot of makerspace labs that require special exhausts for laser printers, 3-D printing, and fabrication.
Chuck Dale-Derks: Trends include greater energy efficiency, voice-evacuation fire alarm systems, and a greater concern for (along with a larger number of) special-needs children. Card-access systems are also expanding to keep track of entry and exits and to keep facilities secured.
Rodney Oathout: We see data analytics as an emerging trend in K-12 projects today. Data analytics can be defined in many ways, but the most common interruption is a series of rules used in conjunction with the building automation system (BAS) to identify when the HVAC system is operating outside of the expected parameters. In a way, the systems continuously commission a building to identify opportunities for saving energy and managing system operation. These systems can have educational programs integral to the operation that can be used in STEM (science, technology, engineering, and math) curriculums.
Michael Rader: One of the most common trends that we see is the desire to create spaces that offer flexibility for different types of learning. This could range from individual study to team-collaboration spaces. The systems serving these spaces must be flexible and scalable to accommodate constant change.
CSE: What trends and technology do you think are on the horizon for K-12 school projects?
Rader: We are seeing trends toward customized learning approaches that are student- specific. This requires a greater flexibility in installed infrastructure since the program varies with the number of students.
Dale-Derks: We’re seeing fault-detection diagnostics for HVAC systems, voice amplification in every classroom, large-format touchscreens of at least 95 in., charging carts for tablets, and tablets for every student. Teachers are using mass communication apps to communicate with students’ cell phones as encouragement reminders for homework or assignments that are due or for encouraging participation in extracurricular events. Card access and camera surveillance are also growing in quantity and are necessary to keep the children and staff safe.
CSE: What are engineers doing to ensure schools—new and existing—meet the challenges associated with emerging technologies?
Dale-Derks: We must continue to learn and stay abreast of new technology and new methods of teaching. We also are encouraging schools to aggressively save energy so that the new technology can be accommodated.
Rader: Engineers must be conversant in the requirements of emerging technologies and provide the infrastructure to support not only current requirements but also potential changes. This means that we must be active in various education-related organizations as well as be close to our vendors and manufacturers.
CSE: Tell us about a recent project you’ve worked on that’s innovative, large-scale, or otherwise noteworthy.
Evan J. Hammersmith: We recently completed a 350,000-sq-ft high school in Ohio for a community that was eager to have a geothermal HVAC system. As we reviewed different system options, we found that the budget could not accommodate a full geothermal system and still meet the district’s other priorities. Our solution was to design an optimized hybrid geothermal system. This allowed us to size the borefield for the heating load. We supplemented it with a fluid cooler for heat rejection and a pair of condensing boilers for supplemental heat. The optimization came through using the fluid cooler and boilers to reject or inject heat into the condenser-water loop in the early spring and late fall to maintain ideal condenser-water temperatures for maximum heat pump efficiencies. The net result was that we were able to provide 90% of the benefits of a full geothermal system at 60% of the first cost.
Chien: Typically, schools are only 2 or 3 stories in height. Along with KPF and Studios Architects, we recently completed a new 11-story, 180,000-sq-ft, K-12 independent school (Collegiate School) in New York City. The school was to have LEED Silver certification. To achieve this, chilled beams, gas-fired condensing boilers, and ice storage were implemented. Other unique features include a stair pressurization system, smoke-control system, and a post-fire purge system—all requirements of a high-rise building in NYC.
Dale-Derks: For a high school in Missouri, we provided a layout and cost analysis for a geothermal-source heat pump as part of the central plant. The optimal geothermal well field would provide 25% to 33% of the central plant capacity and would require a geothermal field of 60 wells in a 5×12 matrix, covering an area of about 80×220 ft (wells spaced 20 ft apart). The premium cost of the installation would be about $480,000 and would save at least $23,000/year. This would offer a payback of about 20.8 years. Even though the payback is good, the school district opted to build more classroom space and forgo the geothermal portion of the central plant. Space is allowed for installation in the future if they desire to do so. The limited availability of geothermal well installers increased the cost and lengthened the payback.
CSE: Have you designed any such projects using the integrated project delivery (IPD) method? If so, describe one.
Dale-Derks: Yes, although not to the full recommendations of the 2007 American Institute of Architects (AIA) Integrated Project Delivery Guide. We had biweekly meetings with the client group of administrative staff, board members, and teachers from multiple schools to vet new ideas and layouts and discuss possibilities for modifications to layout and alternative designs. The discussion took several meetings and many hours when determining how to provide privacy and security for gender-neutral restroom layouts. The end design used toilets with partitions for all required fixtures.
CSE: Each type of project presents unique challenges—what types of challenges do you encounter on projects for K-12 schools that you might not face on other types of structures?
Chien: Gymnasiums that are used for multipurpose functions, such as graduations and other school functions, can push the maximum occupancy to its limit. Normally, a gymnasium would be used for anywhere between 40 to 80 students (assuming two or four classes per period). However, during a major school function, these spaces can see the occupancy increase to between 600 and 800 people. Designing an HVAC system to control the temperature in a space with such a wide range of occupancy can be challenging. One needs to design the HVAC system so it can properly dehumidify and cool the space both during normal and maximum occupancy.
Rader: K-12 schools offer challenges in their funding as well as their constituency. Often, K-12 schools are foundational to the community they serve. This means that there are a lot of stakeholders with differing perspectives and goals. The balance of meeting or exceeding expectations while bringing best practices to bear under typically tight budget constraints is always a challenge.
CSE: Is your team using BIM in conjunction with the architects, trades, and owners to design a project? Describe an instance in which you’ve turned over the BIM model to the owner for long-term operations and maintenance (O&M) or measurement and verification (M&V).
Rader: Yes, our firm has been involved in multiple projects using BIM, ranging from level of design 200 through level of design 500. The biggest challenge that we see is how each team member approaches, develops and implements, and maintains their models. Having an ongoing dialogue is critical from day one.
Dale-Dirks: We have used BIM, specifically C4R on A360. We have also used AutoCAD MEP to generate a set of drawings for a waste-treatment facility. In my opinion, BIM is a marketing stratagem of Autodesk to gain market share and income stream from ever-increasing fees; however, there is finally some benefit in the construction industry. Early versions of MEP or Revit had challenges with standard pipe-material dimensions and difficulties in sloping lines. Only the newest version of Revit can push sheet metal to the CNC machines to fabricate ductwork. Models can also be used to set duct and pipe anchors in the field, but there is still pushback from trade unions to require a fitter work with the staff operating the tremble units. Our designs are Level 100 and still lack a lot of detail. Structural components are missing from the model at this level, such as flanges and kickers, which can cause clashes when the designs are developed to Level 400 in construction. The software does not make it easy to adequately label the drawings for a PDF set of paper documents.
Sometimes it feels like we are spending hours to use software to show detail that could have been shown with pencil and paper in minutes. Then there is the discussion about turning over the model to the contractors and, if the contractor modifies the layout to coordinate the details while generating and revising the model to Level 400 for construction, how much time and effort should the engineer of record spend with the contractor to retain appropriate comfort with the details of the design? Our 2015 and 2016 trials of developing projects with Revit had us desiring to retain and work with a single model. We have since agreed that multiple models must be retained and kept separate so the files remain manageable and the computers crash less frequently. We have yet to find an owner that wants to own a software license and can use the model to its full capabilities. I don’t think BIM is going away, it just has a long way to go before it is as useful as the concept would like to suggest.
Chien: Yes, currently our firm has more than 70% of our projects using BIM as the design platform. Mechanical, electrical, plumbing (MEP) firms are using BIM software with architects and other trades in order to be more coordinated during the design phase and aid contractors in the construction phase. Recent projects have had as-built BIM models drawn by the contractor and submitted to the owner as as-built drawings.
CSE: It seems owners constantly want more features, but with a tighter budget. How are engineers designing K-12 schools to keep initial costs down while also offering appealing features, complying with relevant codes, and meeting client needs?
Oathout: These days, it seems that every market sector desires more for less. We engage our K-12 clients in many ways to ensure they understand the requirements for new codes and other requirements that will affect the design. We also need to understand their capabilities and preferences for system selection and equipment types. These series of questions help prioritize important features that achieve the goals and objectives of the client. It also helps the design team identify system features that may not be necessary or are subject to inexpensive, creative solutions to balance the budget. One of the most important features of the process is engaging the maintenance staff and users during initial occupancy with functional training, so they understand the nuances of the design and the intent is ultimately realized by the occupants.
Rader: Budgets are always an issue with K-12 projects. We must strive to identify the core drivers that an owner is looking for and expend time and money satisfying those goals in lieu of taking a more diluted approach. It is also helpful to look at different funding mechanisms.
CSE: High-performance design strategies have been shown to have an impact on the performance of the building and its occupants. What value-add items are you adding to K-12 schools to make the buildings perform at a higher level?
Dale-Dirks: Direct digital controls and energy recovery are now standard in every project. Some form of commissioning is an absolute necessity. We provide at least a low-level form of commissioning to minimize callbacks and keep our clients happy. Having remote access to the temperature control system and reviewing facility operations over the first year ensures the systems are operating as designed and seasonally tweaked for optimum performance. Forcing the accounting department to communicate energy expenses to the maintenance department is also a necessity for facilities to operate properly.
CSE: K-12 schools are influencing students toward their future careers, particularly in the STEM field. What unique building systems or elements have you included in a design or specification to include more vocational education areas?
Rader: We have tried to make the building and building systems part of the program relative to STEM. This includes energy dashboards and renewable energy sources as well as visible system elements.
CSE: Technology is a key aspect of building high-tech schools of tomorrow. What has your firm done in this field? How have you incorporated technology into the MEP, fire protection, and lighting elements?
Chien: We have included metering of chilled water and steam usage to monitor energy use for a building, provided waterflow sensors for emergency eyewash showers for classroom labs, and provided fast-reacting, pressure-independent control valves to provide energy savings for fume hoods in science classrooms.