What advantage does a 4-pipe hydronic heating/cooling heating system have over a 2-pipe hydronic heating/cooling system?

Correct Answer: Option B — A 4-pipe hydronic heating/cooling system allows simultaneous heating and cooling of different zones, whereas a 2-pipe hydronic heating/cooling system does not.

A 4-pipe system features dedicated supply and return lines for both hot and chilled water. This configuration allows simultaneous heating in some zones and cooling in others, providing superior flexibility and comfort control compared to 2-pipe systems, which can only provide either heating or cooling to the entire loop at once.