Mel Tschumper has two priorities for the heating system at South Dakota’s Andes Central High School: reliability and efficiency. Those two goals get to the heart of what made propane heating such a valuable part of the 55,000-square-foot addition designed by architecture and engineering firm TSP.

“Being in South Dakota, we get some 20-below and 30-below wind chills,” says Tschumper, head of maintenance and custodians for the Andes Central School District in Lake Andes, South Dakota. “And all winter long, I have never had one complaint from any of the teachers or students about being cold. The propane system is smooth; the heat is reliable. All the rooms are consistent day by day.”

The performance and flexibility that the propane heating system provides helped to earn the school and its designers at TSP recognition with the grand prize in the 2019 Propane Project of the Year awards. In this video, Tschumper, project architect Chase Kramer, and senior mechanical engineer Roger Nikolas describe their design approach to this remote project and take a look at how the building is performing after several years in operation.

Achieving LEED-like performance

Located in a rural agricultural community in south central South Dakota, the Andes Central school project united the district’s 350 students on a single campus by adding to the existing 25,000-square-foot elementary and middle school. With a modest budget, the TSP team had to manage upfront costs while also meeting ambitious sustainability goals and allowing for future adaptability. Kramer says the team was seeking LEED-like performance.

“One of the things was ensuring that we had a really strong thermal envelope, whether that was more than the basic requirement for insulation in the walls or making sure that there were high-quality windows on the project,” Kramer says.

The spacious mechanical room includes two 2,500 MBH propane boilers with a 93 percent efficiency rating to heat the new school and replace the existing building’s old boilers.

For the mechanical systems, the design team originally considered a geothermal system, but it became clear early on that it wouldn’t fit in the budget without sacrificing other project priorities, Nikolas says. “Drilling wells is expensive and those costs, they’re just prohibitive,” he says. Adding a new well field also would have taken up valuable land that was earmarked for future expansions. “So that would have limited their ability to construct additions to this facility in the future.”

Instead, Nikolas was confident the project could meet comfort and efficiency goals with the “tried and true” approach of propane boilers. Two 2,500 MBH condensing Lochinvar Crest propane boilers supply a 160-degree-Fahrenheit heating loop to provide perimeter radiant heat in the classrooms as well as hydronic coils in the air-handling system. “With a propane boiler system, we’re able to ratchet that temperature up on that heating loop at times when we need it,” he says. “So when you get 20-below temperatures — and we get that every winter — we really want to make sure that that skin of the building is warm.”

School water heating and cooking

For domestic hot water, Nikolas specified two 95-percent-efficient PVI Conquest propane water heaters with internal storage. “There’s quite a bit of usage for the building because we have athletic areas and showers, so we chose to use separate systems for that because it allows them to turn that boiler plant down or even shut it off in the summer,” he says. Although the design team looked at electric water-heating options, they would have required a larger amount of hot-water storage, resulting in much higher energy costs for the school district.

The propane water heaters’ ability to provide large amounts of hot water is particularly useful in the kitchen, where the staff use it constantly for dishwashing, Tschumper says. The cooks also rely on propane cooking equipment, including two convection ovens, a six-burner stove, a kettle, a steamer, and breadmakers. “I don’t think they could be as efficient with electricity as they would with propane,” Tschumper says.

Classroom and design versatility

Beyond the mechanical systems, the TSP team also built flexibility into the way the building and its rooms were designed. Classrooms can be adapted for multiple seating arrangements ranging from a circle to a more traditional setup, and breakout spaces in between the classrooms can accommodate quiet work or meetings. The science labs were designed as “classatories,” where the desks can be set up in a traditional lecture setup but then slide and lock into place to form peninsulas connected to the lab equipment, such as sinks and propane connections for Bunsen burners.

The science labs were set up as versatile “classatories” that can be utilized in a traditional lecture format or reconfigured to form lab stations.

The architects were also thoughtful about the way the high school integrated with the existing elementary and middle schools. To provide access to the cafeteria for the high school without disrupting the younger grades, the designers added a corridor along the north that provides a separate entrance to the cafeteria while also forming an interior courtyard that could be used for outdoor classes in the future.

For Tschumper, who attended the original high school in Lake Andes, graduating in the 1970s, the successful project is a source of pride. Compared with the old building, where students frequently wore coats in the winter when the fuel oil heating system couldn’t keep up, the new building is more comfortable for students and easier to maintain.

“It’s a beautiful building in a beautiful location, and the school is much more efficient,” Tschumper says. “And to me, my name is on the project, so I’m going to do the very best I can to make our school shine.”