What does a 'control diagram' illustrate in an MEP context?

A control diagram serves as a crucial tool in the context of mechanical, electrical, and plumbing (MEP) systems by visually representing the operational logic and interconnections of various components within these systems. It illustrates how different elements, such as sensors, controllers, and actuators, interact to achieve desired outcomes in system operations. This type of diagram is essential for understanding the sequence of operations, the flow of information, and the relationship between different system parts.

For instance, in a building's HVAC system, a control diagram can depict how the thermostat communicates with the heating and cooling units, detailing the conditions that trigger specific responses. This clarity is vital for engineers and technicians during design, implementation, and troubleshooting phases, making it easier for them to ensure that systems function harmoniously and efficiently.

The other options address different aspects of MEP project documentation, such as overall building layouts, budgeting, and material listing, which focus on physical and financial planning rather than the operational logic of systems.