Hydronic systems with separate supply and return lines are known as which configuration?

Hydronic systems with separate supply and return lines are known as which configuration?

• A. One-pipe systems
• B. Three-pipe systems
• C. Branch-pipe systems
• D. Two-pipe systems

Answer: (D)

Two-pipe configuration means there are two distinct pipes: one carries hot water from the boiler to the radiators, and the other carries the cooled water back to the boiler. This separation lets you balance flow more precisely and control radiator temperatures with valves, and it supports simple zoning since each loop can be fed and returned independently. In contrast, a single-pipe setup uses one line for both supply and return, making balancing and temperature control harder, while a third-pipe arrangement adds another line for specialized control in larger or more complex systems.

Two-pipe configuration means there are two distinct pipes: one carries hot water from the boiler to the radiators, and the other carries the cooled water back to the boiler. This separation lets you balance flow more precisely and control radiator temperatures with valves, and it supports simple zoning since each loop can be fed and returned independently. In contrast, a single-pipe setup uses one line for both supply and return, making balancing and temperature control harder, while a third-pipe arrangement adds another line for specialized control in larger or more complex systems.