Which code is referenced when fire alarm and signaling equipment interfaces with HVAC systems?

The correct answer is based on the function and purpose of the NFPA 90A code, which specifically addresses the installation of air conditioning and ventilating systems. When fire alarm and signaling systems interface with HVAC systems, NFPA 90A provides essential guidelines to ensure that both systems operate effectively in case of a fire. This code outlines the requirements for the design and installation of ductwork and the interaction with fire alarms, allowing for proper smoke control and the safe evacuation of a building.

By adhering to NFPA 90A, practitioners can ensure that the fire alarm systems coordinate with HVAC operations to halt airflow or activate smoke control measures when a fire is detected, thereby preventing the spread of smoke and fire through the building's ventilation system. This integration is crucial for maintaining safety and compliance with fire protection standards.

The other codes mentioned—NFPA 70, which pertains to the National Electrical Code, NFPA 101 that addresses life safety from fire in buildings and structures, and NFPA 75 which deals with the fire protection of information technology equipment—do not specifically focus on the interface between fire alarm systems and HVAC, making NFPA 90A the most relevant choice in this context.