Designing efficient K-12 schools: Sustainable buildings/energy efficiency
In a digital age, children across the U.S. are more technologically advanced than ever—and they require educational facilities that can keep up. Here, engineers with experience working on K-12 schools share views on sustainable buildings and energy efficiency.
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 unusual systems or features are owners requesting that help save energy and/or electricity when a space is unoccupied?
Lentz: The most frequent request is to tie the HVAC system into occupancy sensors so that the area’s HVAC system will shut down when unoccupied.
Rader: The most important feature is to know when a space is unoccupied. Providing the technology to do this in an economical way can be a challenge. However, given the increasing integration between low-voltage systems, this is becoming easier.
CSE: The International WELL Building Institute’s WELL Building Standard is the first certification focused on enhancing health and well-being in buildings. Encompassing seven factors: air, water, nourishment, light, fitness, comfort, and mind, the program aims to reach the same recognition as the U.S. Green Building Council’s LEED certification. Describe a client who has requested elements like this.
Dale-Dirks: No one has requested following all or part of this standard. It has been our approach to bring up discussion during the design process to make the owners aware of this consideration.
CSE: Energy efficiency and sustainability are frequent requests from building owners. What net zero energy and/or high-performance systems have you recently specified in such facilities?
Oathout: Our company was involved in the design of a net zero-ready high school located in the desert, in the Southwest region of the United States. An interesting part of this project was the desire by the school district to use a large outside area for educational purposes and dining. The climate in this area meant that a design strategy would be necessary to make the dream a reality. The first step was to define acceptable thermal-comfort parameters. Once the parameters were determined, our team used a series of simulation tools to inform the design of the building, building orientation, shade structures, landscaping, and other features to achieve the designed outcome.
Chien: We have completed projects incorporating high-performance envelopes in combination with radiant heating and cooling systems with dedicated ventilation. We have also designed the use of earth ducts to preheat and precool ventilation, which provided free cooling and heating with minimal fan energy used.
Lentz: We have recently designed two net zero schools with geothermal HVAC systems.
CSE: What types of renewable or alternative energy systems have you recently specified to provide power in K-12 schools?
Rader: We have specified several alternative energy systems, such as photovoltaics, thermal solar-evacuated tubes, and wind turbines. A significant challenge to these is their first cost. We overcame some of this challenge through utility rebates as well as additional state reimbursement if the project acquired LEED Silver certification or two Green Globes.
Oathout: K-12 buildings are excellent opportunities for the implementation of photovoltaics. Solar energy can manifest itself in many ways, like shade for play areas or cars, simple power generation on rooftops, or in creative ways integral to the architecture of the building. The most exciting development in solar energy is the cost of implementation is approaching a level that is viable in most areas in the United States. The implementation of solar energy also has many educational opportunities in STEM-related curriculums.
Lentz: We have installed photovoltaics, which always involves the challenge of where to place the solar panels.
CSE: What are some of the challenges or issues when designing for water use in such facilities? What types of low-flow fixture, water reuse, or other techniques have you designed?
Lentz: The largest challenge with water usage is fixture type and flow capacity. Our standard design is low-flow water fixtures, but due to continued requests for even further water-use reduction, we are now specifying waterless fixtures for some schools.
Rader: One challenge that we have encountered is renovating existing facilities with low-flow fixtures. The existing sanitary infrastructure must be evaluated prior to simply replacing high-flow fixtures with low-flow fixtures to ensure that the system will drain properly.
Chien: Coordination of the proper installation heights of the water closets, flush valves, and grab bar can pose a challenge. We often encounter child-height water closets, especially in the lower grades. Another issue may be with any special-needs students who could be agitated or upset by the sudden flushing sound of an automatic sensor-type water closet. In this instance, manual valves would be a more appropriate option.
CSE: How has the demand for energy recovery technology influenced the design for K-12 schools?
Lentz: The rising demand for energy recovery has forced engineers to design more advanced HVAC systems than those installed in schools in the past.