Optimizing hydronic distributions for energy efficiency
We present the technical article, based on the scientific work, written by Jean-Christophe Carette, Director of Hydronic College and Eric Bernadou, Senior Marketing Manager.
Optimizing the hydronic network in a HVAC system reduces energy consumption and improves the control and delivery of comfort.
Condensing boiler and chiller efficiencies are directly influenced by the return water temperature of the system with potential loss of efficiency of up to 15%. Understanding which control modes and loops avoid degrading return water temperature is therefore essential and will be reviewed.
In cooling systems, electrical pumping costs represent up to 7% to 17% of the total cooling energy consumption. A methodology combining the use of differential pressure controllers and remote Dp sensor for the variable speed pump will also be discussed, which allows reducing the pumping costs by up to 40% compared to a non-optimized situation.
In heating systems, the room temperature being 33.8°F too high costs 6% to 11% of the annual plant energy consumption. Furthermore the trend to higher Delta T in heating requires higher precision in flow adjustments. This emphasizes the importance of delivering the required temperature with precision every time by working with components with low hysteresis and low influence of differential pressure.
Finally, we will see through two real cases that with these different areas of optimisation, one can in fact reduce on average the energy consumption of an existing hydronic system by up to 30%.