MORE TOPICS | HVAC
Right-Sizing Your System With Hydronics
Working toward net-zero energy may start with existing infrastructure.
Jim Nolan | Xylem
As the commercial building sector advances toward decarbonization, there is a clear opportunity—reduce the environmental impact of existing buildings starting with heating, ventilation and air conditioning (HVAC) systems. These systems account for nearly half of energy use in commercial facilities and are a major source of greenhouse gas emissions. While new construction tends to get the spotlight, the biggest and fastest gains are often found in improving what is already in place.
One of the most effective ways to do that is by right-sizing HVAC systems—matching system capacity to how a building actually operates. For years, systems were designed around peak load assumptions with built-in safety margins. In reality, buildings rarely run at those peak loads. The result is oversized equipment that wastes energy, drives up costs and puts unnecessary strain on components.
The Measurable Impact of Right-Sizing
Right-sizing brings systems back into alignment by recalibrating pumps, heat exchangers and controls to meet real, dynamic demand, and the payoff is almost immediate—both in how the system performs and what it costs to run:
- Reduced energy consumption and decreased operating costs
- Lower greenhouse gas emissions and improved sustainability performance
- Enhanced occupant comfort through better temperature control
- Longer-lasting equipment with less wear and tear
- Less required maintenance and fewer system failures
For building owners looking to improve Energy Use Index (EUI) without major capital investment, right-sizing provides a practical and immediate solution.
Hydronics for Efficient Retrofits
Hydronic systems are especially suited to right-sizing initiatives. Because water is inherently more efficient for transferring heat than air-based systems, hydronics offers better control and performance from the start. Equally as important, these systems bring the flexibility today’s buildings demand.
As more facilities shift toward renewable energy sources like solar and geothermal, hydronics provide a natural fit. They simplify the transition to solutions like water-source heat pumps, often with less disruption than traditional systems. That adaptability helps extend system life, maintain performance and reduce long-term costs.
Designing for Real-World Performance
Effective right-sizing starts with understanding how a building actually operates. Traditional static load calculations alone are no longer enough. Today’s approach relies on dynamic load modeling, variable speed technology and smart system design that reflects real-world conditions. Systems can respond in real time, scaling output to match demand. High-efficiency components improve heat transfer, modern controls enhance system responsiveness and continuous monitoring helps operators spot inefficiencies before they become problems.
Using Data to Drive Better Decisions
The best right-sizing strategies are grounded in data. Tools like the Hydronic Industry Alliance’s Building Efficiency System Tool (BEST) help evaluate system options, compare life cycle costs and estimate energy performance before implementation.
Metrics like part load efficiency value (PLEV) further enhance decision-making, shifting the focus to how systems operate under typical operating conditions—not just at peak capacity. This gives engineers and designers a clearer, more accurate picture of how buildings actually function and ensures more accurate system design.
Sustainability Gains That Add Up
The benefits of right-sizing go beyond efficiency—they directly support broader sustainability goals. Properly sized systems can significantly cut emissions, while hydronic designs help reduce water waste and extend equipment life. Retrofitting instead of replacing also reduces embodied carbon, avoiding the environmental cost of new manufacturing and installation.
With buildings responsible for nearly 40% of global carbon dioxide (CO2) emissions, these incremental improvements can drive meaningful impact at scale.
Built for Flexibility & the Future
Looking ahead, flexibility is essential. Regulations will continue to evolve, and electrification will reshape how buildings operate. HVAC systems need to be ready.
Hydronic systems make that easier by supporting building expansion or reconfiguration, integrating smoothly with renewable energy and helping facilities stay compliant as standards change. Because hydronic systems are built to last, equipment can last well over 25 years.
A Practical Path Forward
The path to net-zero energy does not start with new construction, it starts with the buildings in use. Right-sizing HVAC systems is one of the fastest, most accessible ways to improve performance, reduce environmental impact and control costs. By focusing on smarter system design, using real-world data to guide decisions and integrating flexible, efficient technologies, engineers, contractors and building owners can make meaningful progress today—without waiting for tomorrow’s solutions.
As the industry continues its transition toward decarbonization, the opportunity is straightforward: Optimize what you have, design with flexibility in mind and prioritize efficiency at every stage. The result is lower energy use, reduced emissions and buildings that are not only higher performing but ready for whatever comes next.
Jim Nolan is the north central market development manager for Xylem’s Bell & Gossett. In this role, he is responsible for sales, training and product support at all levels of the distribution chain. Nolan has 23 years of experience in the HVAC and hydronics industry in a variety of roles in sales, product management and as a manufacturers’ rep executive. His principal areas of interest are energy savings, hydronic systems, training and engineered solutions to solve customer requirements and enhance return on investment. For more information, visit xylem.com.
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