Ice-on-Coil Thermal Storage Explained

As HVAC professionals, understanding the various methods of thermal energy storage is crucial for optimizing energy efficiency in our systems. One innovative approach gaining traction is ice-on-coil thermal storage. In this article, we will delve into what ice-on-coil thermal storage is, how it works, and its benefits for both commercial and residential applications.

What is Ice-on-Coil Thermal Storage?

Ice-on-coil thermal storage refers to a system where ice is formed directly on coils or tubes within a storage tank. This tank is insulated to prevent heat exchange with the surrounding environment, ensuring that the ice remains frozen until it is needed for cooling. The primary goal of this system is to shift cooling demand to off-peak hours, thereby reducing energy costs and peak load on the electrical grid.

How It Works

The operation of an ice-on-coil thermal storage system is relatively straightforward:

1. During off-peak hours, typically at night, the HVAC system runs in a refrigeration mode that circulates a refrigerant through the coils.
2. As the refrigerant flows through the coils, it extracts heat from the water in the storage tank, causing the water to freeze and form ice on the coils.
3. Once the ice has formed, the system can be turned off or set to a lower capacity, thus reducing energy consumption during peak demand periods.
4. During peak hours, when cooling is needed, the stored ice is melted by circulating chilled water through the coils, which absorbs heat from the building and provides effective cooling.

Benefits of Ice-on-Coil Thermal Storage

• Energy Cost Savings: By shifting energy consumption to off-peak times, users can take advantage of lower electricity rates, leading to significant cost savings.
• Peak Load Reduction: This system reduces the peak cooling load, which can help in avoiding the need for additional equipment and infrastructure.
• Enhanced System Efficiency: Ice thermal storage systems generally operate more efficiently than traditional cooling systems, improving overall performance.
• Environmental Benefits: Reducing peak demand can lead to lower greenhouse gas emissions from power plants, contributing to a more sustainable environment.

Conclusion

For HVAC professionals, incorporating ice-on-coil thermal storage systems into designs can lead to significant benefits for both the customer and the larger electrical grid. By understanding the principles and advantages of this technology, we can better serve our clients and foster sustainable practices in our industry. As energy costs rise and the demand for cooling grows, systems like ice-on-coil thermal storage will undoubtedly become a valuable part of our HVAC toolkit.