Five ways hydronic systems continue to prove their flexibility

Modern hydronics technology can help future-proof HVAC designs.

By Barry Lee

Pictured: Lucas Oil Stadium's transformation into two massive temporary pools powered by plate and frame heat exchangers connected to the building's heating system. image cOURTESY OF XYLEM.

According to the U.S. Green Building Council, designing for flexibility involves conserving resources associated with the construction and management of buildings. This means considering design choices that enable flexibility around ease of future adaptation and for the service life of components and assemblies. The requirements to meet this LEED standard vary depending on the building type or structure, but the motivation is the same: design efficiently within the structure in question, employing strategies that prioritize system adaptability and performance.

When it comes to flexibility in heating and cooling, no better choice comes to mind than hydronic systems. In this case, flexibility refers to the variety of options within a hydronic system, considering occupant comfort, different-sized structures and energy-efficient operations. Coupled with government mandates and standards for energy conservation and electrification at an all-time high, there’s a reason that hydronic systems haven’t lost their edge over time—and don’t seem to be going anywhere anytime soon.

The modern HVAC choice

In the U.S. alone, 30% of commercial floor space is heated with a boiler, and most of these buildings are larger than 50,000 square feet. This requires flexible, agile systems that can maximize control and offer:

  1. Variable temperature: Most hydronic HVAC systems will either have a boiler, chiller or both as the heating or cooling mechanism. As part of this system, water circulates throughout it based on heating and cooling demands that can vary based on the size of the building, number of occupants and different zones within the building. A tried-and-true example of system precision, variable temperature within hydronic systems has evolved over time to become more advanced — including the development of even more responsive temperature controls and the advent of digital tools in recent years that provide flexibility in management.
  2. Zone distribution: Schools, dormitories, hospitals and multifamily complexes all come with different occupancy standards—and different temperature control areas that require a lot of flexibility. For instance, consider a hotel versus a museum. A museum exhibit may require cooler areas that need to be temperature-controlled for optimal art display conditions, while an 11-floor hotel will require pumps for different zones of the hotel, giving guests flexibility over individual temperature control.
  3. Scalability: Whether it’s in the context of a small space or very large room, hydronic systems boast a level of customizability and configurability for a range of piping systems and applications. For example, if another room is added to a building, the pipe connection can be combined with another pump, enabling more flexible installation as well as the ability to scale a system up or down over time. In this way, modern hydronic systems can be tailored to meet the exact needs of custom applications and building designs.
  4. Energy efficiency: As HVAC equipment prices continue to rise, equipment and systems that have a long life cycle and cost efficiencies equally rise in importance. It’s a well-known fact that hydronic systems can be up to 30% cheaper than competitive technologies, but their energy efficiencies are unmatched given the energy-intensive nature of such technologies. For instance, water can carry heating and cooling energy through a building using less than 10% of the electrical energy required by a forced air distribution system of equal capacity. These same forced air systems can experience significant efficiency losses from leaks in installation and poor insulation. With the growing adoption of Electronically Commutated Motors (ECM), users only use as much pump energy at any given point as they need it, reducing power consumption overall. ECM motors also offer a lot of control options based on pressure and temperature, with the end goal of saving more energy and repurposing a system.
  5. Future-Proofing: With the advent of Wi-Fi-enabled connectivity and the Internet of Things, building professionals are increasingly seeking more end-to-end solutions that offer remote operational capabilities. The ability to integrate such capabilities with hydronic systems and connect to a building management system through open network protocols like BACnet and Modbus will be a game-changer for many. With this shift from mechanical to digital also comes more interest in renewable energy sources that are driving a deeper conversation around hydronics as the main viable option to advance decarbonization and net-zero strategies.

Hydronic systems have been around for decades and while their benefits are clear, what’s in store for their future is still very much unfolding. Ultimately, the goal of our industry is to act as advocates and educators of hydronics technology as the flexible, future-proofed and most efficient choice for HVAC design.

Hydronic systems have been around for decades and while their benefits are clear, what’s in store for their future is still very much unfolding. Ultimately, the goal of our industry is to act as advocates and educators of hydronics technology as the flexible, future-proofed and most efficient choice for HVAC design.

In closing, I’ll share one recent example of hydronics in action: the case of two massive temporary pools built for a competition event at Lucas Oil Stadium. Powered by plate and frame heat exchangers connected to the building’s heating system, steam from an underground tunnel is converted for the building heat to ensure uniform and optimal temperatures for 1.8 million gallons of water. This is a modern-day example showcasing the convergence of innovation and flexibility, whereby an existing underground tunnel paired with modern hydronics technology can result in a powerful combination and present an inspiring model and example for the future.

ABOUT THE AUTHOR
Barry Lee is product manager for circulator pumps at Xylem.