What characterizes a 4-pipe system in HVAC?

A 4-pipe HVAC system is characterized by its ability to provide both heating and cooling simultaneously, which is achieved through the use of two separate pipes for each function: one set of pipes carries chilled water for cooling, while the other set carries hot water for heating. This design allows for the flexibility to condition various zones of a building according to their specific needs, providing comfort in different areas without interrupting the overall system operation.

In practical terms, this means that while one area of a building may require cooling to maintain a comfortable temperature, another area can simultaneously receive heating if it needs to be warmer. This dual-pipe approach enables more precise temperature control and improves overall energy efficiency in a commercial setting. Overall, the unique configuration of a 4-pipe system is what distinguishes it from other HVAC systems.