What is the correct water temperature differential for Hydronic Systems?

In hydronic systems, the correct water temperature differential, known as Delta-T, is typically around 20°F. This differential represents the difference between the supply water temperature and the return water temperature. A 20°F Delta-T is considered optimal as it allows for efficient heat transfer while maintaining adequate flow rates in the system.

Using a 20°F differential ensures that the water is heated sufficiently before returning to the boiler or heat source. This temperature range helps to optimize the system’s efficiency, reducing energy consumption, and ensuring the comfort levels in the space being heated.

Other Delta-T values, although theoretically possible, may lead to inefficiencies. A smaller differential could indicate a system that isn’t effectively transferring heat, while a larger differential could signify excessive flow rates or a poorly designed system. Hence, the 20°F Delta-T is a standard used for effective and efficient operation of hydronic systems.