The primary purpose of a fire department connection (FDC) is to:

The primary purpose of a fire department connection (FDC) is indeed to allow a water supply for emergency response. This connection is a crucial feature in fire protection systems, providing firefighters with quick and reliable access to additional water from a municipal supply or other sources when responding to a fire.

The FDC is typically located on the exterior of a building and is connected to the sprinkler and standpipe systems within the structure. This ensures that, in the event of a fire, firefighters can augment the building's internal water supply to effectively combat the flames. The connection is designed for ease of access, allowing emergency responders to hook up their hoses quickly without needing to wait for the building’s internal systems to operate.

Understanding the purpose of an FDC is vital for safety planning and compliance with fire codes, as it enhances the effectiveness of fire suppression efforts and helps to protect lives and property. Other options such as housing exit signs, providing backup power supply, or managing smoke control do not align with the primary function of the FDC, which is specifically focused on water supply for firefighting purposes.