Technology drives K-12 school changes for energy efficiency, sustainability
Updates, COVID and tech trends are shifting the way K-12 schools are designed. Here’s a look at the topic of energy efficiency, sustainability and renewable energy systems
- Luis Alvarez, PE, Electrical Engineer, Associate, Page, Austin, Texas
- David Bonaventure, PE, CEM, Principal, Salas O’Brien LLC, Baton Rouge, Louisiana
- Lawrin T. Ellis, PE, LEED AP, Managing Principal, TLC Engineering Solutions Inc., Fort Myers, Florida
- Keith Hammerschmidt, PE, Senior Project Manager, RTM Engineer Consultants, Overland Park, Kansas
- Scott Peck, PE, Vice President, Peter Basso Associates, Troy, Michigan
What level of performance are you being asked to achieve, such as WELL Building Standards, U.S. Green Building Council LEED certification, net zero energy, RESET or other guidelines?
Lawrin T. Ellis: While we have designed a fair number of U.S. Green Building Council LEED schools, including the first LEED Certified elementary school in Florida in 2008, most districts have not pursued any certification due to associated perceived costs. However, we, as a matter course, automatically incorporate sustainability throughout our designs. We began introducing WELL concepts a couple of years ago, but it’s still a conceptual discussion.
Keith Hammerschmidt: RTM has designed schools to LEED certified and net zero capable. The LEED certified schools were designed in the Kansas City area and the net zero school was designed in Springfield, Missouri. In either design it was a combination of working with the entire design team to ensure all aspects of the design were selected based on sustainable design principles. For the LEED project, we worked with the architect to ensure walls and windows were properly designed with proper R-values and placement of windows for best daylight without increasing solar heat gain to the space. A sustainable building can only be achieved from a whole team approach and not just the mechanical or architectural team.
What unusual systems or features are being requested to make such projects more energy efficient?
Lawrin T. Ellis: Due to favorable incentives and energy tariffs with one of the state utilities, we have and continue to design thermal energy storage systems. Up until 2012, the bulk of the systems used static ice TES. However, in 2012 we introduce chilled water storage as more efficient and long-term cost effective alternative. One local district has gone exclusively to chilled water storage TES, to the point of changing static ice to chilled water storage during maintenance replacement of the ice. The goal is more focused on the energy cost savings as opposed to the energy efficiency. However, the chilled water storage systems overall are more energy efficient than the static ice.
Describe a recent project in which the building envelope was complex or unique.
Lawrin T. Ellis: Collier County High School GGG, currently under construction, has an incredibly complex envelope geometry. We use IES VE-Pro for loads and energy modeling and accurately capturing the envelope’s angular geometry, fins with recessed windows, covered open concourses and multitiered construction required time and careful attention to accurately model. In addition, changes through design development and early construction documents provided continuous challenges for our structural design team.
What types of sustainable features or concerns might you encounter for these buildings that you wouldn’t on other projects?
Lawrin T. Ellis: Other than security and student safety, both being key on most public-sector projects, we mostly use the same sustainability approaches and practices.
What types of renewable or alternative energy systems have you recently specified to provide power?
Lawrin T. Ellis: We’ve provided studies and preliminary design concepts for photovoltaics and solar thermal systems. The most significant was a PV system feasibility study that effectively provided net zero for an elementary and middle school on a shared campus. However, due to costs and available funding levels for public schools in Florida, the only design that moved forward was a solar thermal system for a local middle school about 12 years ago.
What value-add items are you adding these kinds of facilities to make the buildings perform at a higher and more efficient level?
Lawrin T. Ellis: To the extent that budgets will allow, we optimize the envelope, use LED lighting throughout, specify high-efficiency equipment and optimize controls to minimize energy consumption. There are more opportunities to employ lighting controls, energy recovery, instantaneous gas water heaters for kitchens and gym lockers in wealthier school districts.
How have energy recovery products evolved to better assist in designing these projects?
Lawrin T. Ellis: With respect to air-to-air devices, the cross-flow fixed enthalpy cores are preferred because they virtually eliminate the cross-contamination and purge associated with enthalpy wheels. We have used multipass for increased efficiency on LEED campuses. We also occasionally use heat-recovery chillers when we have small process loads, but that is not typical.