What is the most common type of fire alarm system in buildings?

The most common type of fire alarm system found in buildings is the conventional system. These systems use zone-based technology where the building is divided into several zones, and any alarm activated in a zone will alert the system to that area. This is practical for many types of facilities because they are generally easy to install, maintain, and operate. Conventional systems are typically less expensive than more advanced systems, making them a popular choice for smaller buildings or applications where the complexity of a more sophisticated system is not necessary.

While manual systems allow individuals to activate a fire alarm by pulling a lever, their reliance on human action makes them less common as a standalone system in comparison to automated systems. Addressable systems, while providing specific information about the location of the fire, are more complex and usually found in larger facilities where precise data is crucial. Photoelectric systems refer specifically to the type of sensing technology used within alarms and can be part of both conventional and addressable systems but do not categorize the alarm system as a whole.

Hence, the correct choice emphasizes the practical application and widespread use of conventional systems in the fire safety infrastructure of many buildings.