Which type of heat detector is most commonly used in fire alarm systems?

Fixed-temperature heat detectors are most commonly used in fire alarm systems due to their straightforward operational principle and reliability. These detectors are designed to activate an alarm when the temperature rises to a predetermined threshold, typically around 135°F (57°C) for general applications. Their simplicity makes them suitable for many environments where potential fire hazards are identified, as they provide a clear and direct indication of a significant temperature increase due to fire.

These detectors are often preferred because they are effective in scenarios where rapid temperature changes are not expected, making them a practical choice for areas like offices, warehouses, and residential buildings. Additionally, fixed-temperature heat detectors tend to have lower maintenance requirements compared to more complex options.

In contrast, other types of heat detectors, such as rate of rise heat detectors, are specifically designed to respond to a rapid increase in temperature, making them more suitable for areas where fast-burning fires are expected. Combination heat detectors integrate both fixed-temperature and rate of rise functions, providing more versatility but also increasing their cost and complexity. Smart heat detectors offer advanced features, such as self-diagnostics and connectivity, but are less common than fixed-temperature units due to their higher price point and specialized applications.