Hydronic heating is generally considered more efficient than steam heating. This is because hydronic systems use hot water to heat a space, which can retain heat for longer periods of time and distribute heat more evenly than steam systems. In addition, hydronic systems can operate at lower temperatures, which reduces energy consumption and can save money on utility bills.

Steam heating, on the other hand, relies on steam to heat a space. Steam systems typically require higher temperatures to operate effectively, which can result in higher energy consumption and higher utility bills. Steam systems also have a tendency to create hot spots and cool spots, which can lead to discomfort in a space.

Overall, while both hydronic and steam heating systems have their benefits, hydronic systems are generally considered more efficient and effective for heating residential and commercial spaces.