An Illinois school district faced the daunting task of overhauling aging HVAC systems and controls in three high schools built decades apart (from 1929 to 1964) without interrupting the school day or after-school activities. By specifying SIEMENS controllers to automate the HVAC system and pressure independent control valves (PICVs), the school district reduced overall labor costs and increased energy efficiency. SIEMENS is a supporter of MCAA26.
Installing a Uniform System
Dave Ulm, director of facilities at Maine Township School District 207, recognized the need to improve indoor air quality (IAQ) in all three institutions, which had different infrastructure, systems, and controls in place, while also trying to balance energy efficiency. Good IAQ includes introducing adequate outdoor air, which provides a favorable environment for education, according to the U.S. Environmental Protection Agency.
To better monitor IAQ and easily maintain uptime, Ulm wanted the same building automation system and controls across all three facilities. Most importantly, it was vital to implement system-wide communication across the entire school district.
To coordinate such a massive project and bring in optimal systems and controls, Ulm turned to teams he knew he could rely on: SIEMENS Smart Infrastructure, Everest Energy & Control Technologies, and Elara Engineering. His long-term relationships with these companies’ highly experienced teams gave him confidence that they would complete the school’s four-year project on time and within budget. Ulm emphasized, “The high schools must open each year in mid-August, and we can’t miss the opening date.”
Upgrading an Aging System
Kicking off the project, Ulm said, “We initially engaged Bob St. Mary, senior engineer at Elara, and his firm to give us a better overall sense of where our building systems were as far as end of life and reliability. It became apparent that we weren’t going to be able to resolve these issues by fixing one component this summer and another component next summer. We needed to invest a significant amount of money.”
The dual duct system and the air handler equipment were 50–60 years old, and the likelihood that outside air was getting into the classrooms was slim to none. “We had carte blanche to really look at the HVAC system as a whole,” said St. Mary. “However, there was just one absolute mandate: to eliminate unit ventilators.” He emphasized, “The challenge with unit ventilators is that they are notorious for being plugged after about five or six years.”
The master plan included standardizing system types, control equipment, rooftop units, and fan coils to simplify and reduce maintenance time. “We came up with a solution that fit all three schools,” St. Mary said. At the same time, sustainability and energy savings drove decision-making. “When replacing the old pneumatic system, which wastes energy, we needed to ensure that the school district had a system that operates well and was energy-efficient with good indoor air quality,” he explained.
Controlling Costs
The most important decision was to standardize all equipment and systems, which led to the selection of SIEMENS controllers and PICVs. According to the design and installation team, these SIEMENS products reduced labor costs during installation and eliminated the need for annual maintenance later.
SIEMENS DXR2 controllers communicate via building automation and control network (BACnet) internet protocol and are easy to preload and program, while the PICVs are self-balancing. Therefore, installers and maintenance staff do not need to touch the controllers or PICVs one by one when doing their work. Furthermore, the PICVs have an integrated design that eliminates the need for a separate balancing valve for rebalancing if the system is expanded, effectively eliminating labor.
Everest President Dan Reynolds said, “We have installed almost 2,500 PICVs. Using the self-balancing PICVs meant we didn’t need someone to touch every valve—which provides significant labor savings up front. There’s also reduced water flow required, and the pump motors don’t have to work as hard. It all adds up to a good decision.”
PICVs also have an automatic differential pressure regulator that automatically adjusts to pressure fluctuations in the system, maintaining consistent flow at any given control setting. The result is maximized delta T, which significantly optimizes energy usage and cost savings by preventing an oversupply or undersupply of heating or cooling.
SIEMENS equipment simplified many other aspects of the project, too. Mark Koscielniak, vice president at Everest, appreciated that he could do much of his own work readying the controllers offsite instead of in the middle of construction.
SIEMENS DXR2 controllers and the QMX series room unit sensors also help increase staff efficiency, Koscielniak explained. “We’re able to gather all of the data generated, sort it, digitize it, and react programming-wise to create the optimal classroom environments,” he said. “We store all this information and make it easy for Maine Township staff to access it when needed to trend and report that the system is operating correctly as designed. If not, alarms are automatically triggered to alert staff of an issue so that they can immediately address any system errors.”
Read a detailed case study about the Maine Township School District 207 here: https://sid.siemens.com/v/u/A6V14285049
Upfront Cost Savings
Although it is too early to have metrics on energy savings, Ulm pointed out some benefits that are already apparent with the building management system, providing transparency and intelligence from a single pane of glass. To date, he said calculations demonstrated a 15–20-percent upfront cost savings over installation of conventional control valves. Overall, the project’s first-cost savings were estimated at $75,000.
“I’m really happy that I can see every high school campus, as well as their systems and control equipment,” Ulm said. “That excites me and it’s a great comfort. Previously, if there was an emergency, I had to go onsite to troubleshoot. Now I can view all the district’s school systems and data on my desktop, troubleshoot and adjust, and then marshal the resources from that point—much more efficient.”
For more information, visit www.siemens.com. MCAA thanks SIEMENS for being a supporter of MCAA26 and providing the digital final program.
