What is an Open Expansion Tank Heating System?

What is an Open Expansion Tank Heating System?

In open expansion tank systems, the position of the expansion tank plays a critical role in determining the system's static pressure. These systems connect the expansion tank openly to the system, allowing it to handle the water expansion during heating while maintaining system pressure control.

Advantages of Open Expansion Tanks

Open expansion tanks facilitate easy pressure control and minimize the risk of water overflow. Compared to closed systems, they offer a cost-effective solution. Due to their simple structure and low maintenance requirements, they are commonly used in small-scale heating systems. These features make them an economical and sustainable option for various applications.

System Static Pressure

In an open expansion tank heating system, static pressure varies depending on the position of the tank. For example, as seen in the diagram below, the circulation pump operates with a static pressure of 3.5 c.m.w. (meters of water column). Proper pump placement enhances system performance and improves energy efficiency.

General Rule

As a general rule, the circulation pump should be positioned at the system outlet. This placement prevents cavitation issues and avoids water overflow in the open expansion tank. Additionally, this setup ensures a more balanced and reliable system operation.

Note: c.m.w: mSS (meters of water column)