In which situations would you install a fire department connection (FDC)?

A fire department connection (FDC) is an essential component of a building's fire protection system, specifically intended to provide an additional water supply to the sprinkler system in cases where the existing water supply is inadequate. This is crucial in ensuring that firefighters can quickly access and utilize water to suppress fires, especially in larger or more complex buildings where the installed sprinkler system may not be able to provide sufficient flow and pressure on its own.

Installing an FDC addresses the critical need for adequate fire suppression capabilities. In many jurisdictions, building codes and fire safety regulations specify the installation of an FDC if the sprinkler system's water supply is deemed insufficient to meet potential fire demands. Thus, having the capability to boost water supply via a connection for fire department use is vital for effective fire response.

In contrast, the other scenarios do not inherently necessitate the installation of an FDC. The presence of multiple floors or a certain number of sprinkler heads does not automatically indicate a need for an FDC unless there is a corresponding issue with water supply adequacy. Additionally, installing an FDC after a fire has occurred would not prevent damage or ensure safety during the incident, making it an ineffective strategy.