Designing high-tech K-12 schools: Sustainable buildings and energy efficiency
The technology at play in today’s K-12 schools is evolving rapidly—inside the classrooms, and in the various systems behind the scenes. Engineers handling such projects, whether the work is on new facilities or retrofits, have their work cut out for them, especially when it comes to sustainable buildings and energy efficiency.
Doug Everhart, PE, LEED AP, K-12 Education Practice Director, Vice President, Henderson Engineers, Kansas City
Jason Gerke, PE, CxA, LEED AP BD+C, Principal, Mechanical/Plumbing Group Leader GRAEF USA, Milwaukee
April L. Halling, PE, Project Manager, RTM Engineering Consultants, Overland Park, Kan.
Brandon Pierson, PE, LEED AP, Lead Mechanical Engineer, IMEG Corp., Rock Island, Ill.
Johnny Wood, PE, LEED AP BD+C, CxA, CPD, Senior Associate, Senior Project Manager, Dewberry, Raleigh, N.C.
CSE: What types of sustainable features or concerns might you encounter for K-12 school buildings that you wouldn’t on other projects?
Wood: One key item we work to ensure is the owner is able to maintain the systems we design for them. Often with energy efficiency comes more complicated equipment and controls. If the owner does not have the staff or experience to maintain the more complicated systems, then the energy efficiency will not be achieved.
Gerke: A growing trend in K-12 schools is to make the energy-efficient systems in a building more visible so they may be used as a learning tool. These sustainable features may include green roofs, rainwater collection for reuse, solar PV systems, or special façade-shading systems. While these systems may be complicated in how they are integrated into a building or how they operate, the school facilities will create simplified explanations for the systems related to how these systems create the overall learning environment for the building occupants. Designing to make these sustainable features visible, cost-effective, and easy to understand sometimes results in a set of conflicting goals that must be balanced by the design and construction team to educate the designers and builders of tomorrow.
CSE: What types of renewable or alternative energy systems have you recently specified to provide power? This may include photovoltaics, wind turbines, etc. Describe the challenges and solutions.
Gerke: Solar PV or solar hot-water systems can be simple add-on renewable energy features to include in building designs. Many times, these systems are added for the purpose of creating a media snip it, but they provide an excellent opportunity to reduce fossil fuel use for a facility. Design teams should always look for opportunities to include renewable energy systems, whether for the flash and bang of including it or to achieve an owner’s design for long-term energy savings and reduced impact on the environment.
Wood: More and more of our K-12 projects are considering photovoltaics today. We design the electrical switchgear with multiple breakers to incorporate the arrays into the system. We then design the system as an alternative to allow the owner to determine at the bidding phase whether to implement the PV system or not.
CSE: What are some of the challenges or issues when designing for water use in such facilities?
Wood: When using low-flow plumbing fixtures, ensure they actually pass the solid/paper waste appropriately. We have actually experienced that in some school systems, due to the type of toilet paper used as a standard, it takes multiple flushes of low-flow plumbing fixtures to pass the waste. Water savings is normally not achieved in this particular case. Installing a low-flow plumbing fixture in the school early in the design process is a way to determine if this is an issue or not.
CSE: As energy codes become increasingly demanding, what are some design practices that have become more common?
Pierson: Energy codes play a significant role in the design of our K-12 projects. Our engineers consistently design for energy efficiency as well as durability for our K-12 clients. Even the most efficient MEP system will not serve a school district well if it is not durable or requires excessive maintenance. LED lighting systems with automatic control systems for occupancy, dimming, and daylighting are the standard for efficient design. The LED lighting manufacturers are offering a wide selection of fixture types and competitive pricing that delivers high efficiency, durability, and value. Mechanical systems are routinely designed with airside economizer systems and power exhaust to provide “free” cooling. Heat-recovery systems are used to temper outside air loads. Demand-control ventilation systems are required by California Energy Code and Title 24 for assembly spaces and auditoriums. The ability to maintain healthy indoor air quality while minimizing the cooling or heating requirement of outdoor air is an effective strategy. Plumbing designs are geared toward water conservation and the use of recycled water. School projects under the jurisdiction of the City of Los Angeles are required to have waste systems designed to be greywater-ready and that use reclaimed water (if available) for toilets and urinals.
Gerke: The increase in energy efficiency requirements in adopted codes has continued the evolution of systems and equipment. Specifically, the mechanical systems in K-12 facilities have continued to become more complex to actively respond and adjust to various building needs. These systems both monitor current space conditions and anticipate changes based on past building fluctuations in use or occupancy. The ability of an HVAC control system to quickly respond to the increase of occupants in a gym for temperature control, humidity control, and ventilation airflow is an important feature that creates comfortable and energy-efficient environments.
CSE: How have energy recovery products evolved to better assist in designing energy–efficient K-12 school buildings?
Gerke: There are many system options for various building types, including sensible or total energy wheels, sensible or total energy fixed-plate cores, and runaround coils with pumped water or refrigerant. These systems have been commercially available for many years, with their uses and applications continuing to evolve into either more complicated or sometimes very simple installations. Using these systems as standard options in AHUs has simplified the application of the equipment. Creating equipment with standard energy recovery options will continue the increased use of this equipment, as well as simplify the control strategies related to the functionality of the systems.
CSE: Have you designed a school in which the students were part of the energy efficiency M&V system via an education kiosk or online/mobile application? Describe the project.
Everhart: Henderson partnered with Olathe Public schools in Kansas on the design for their fifth high school, Olathe West. Their decision to build a highly energy-efficient school began with energy modeling early in the design process. Those results then informed the design, which included the selection of sustainable systems that were later integrated into the ongoing building monitoring system. This system produces live reports on the facility’s electricity, gas, and water usage—providing better control of the building’s systems, more accurate and timely performance data, and the opportunity for early detection of issues. In addition, real-time analytics from the facility’s monitoring system is then integrated into the curriculum of the school’s Green Technology Academy—a program that equips the students enrolled in the academy with the tools and opportunity to learn about the importance of energy-efficient technology and allows them to have a hand in their everyday environment. In addition to being an effective teaching tool and early identification system, the system is allowing the project team to continue making minor tweaks to it, working toward a goal of 40 EUI, which is 34.1% below the ASHRAE 90.1 2007: Energy Standard for Buildings Except Low-Rise Residential Buildings baseline of 60.7 EUI. Now in its second year of operation, the school is well on its way to achieving that goal.