A heat detector that is integrally mounted on a smoke detector must be listed and approved for a minimum of how many feet?

The minimum requirement for a heat detector that is integrally mounted on a smoke detector is a crucial aspect of fire alarm systems, ensuring effective performance and safety. The correct answer, 50 feet, is established by the guidelines in the National Fire Alarm and Signaling Code, which stipulate that such devices must be able to reliably detect temperature changes within this specified range. This distance ensures that the heat detector can adequately cover an area, contributing to the overall effectiveness and reliability of the fire alarm system.

In the context of fire detection, maintaining proper distances between detectors is vital because it impacts the system's ability to promptly identify hazardous conditions. Options that propose shorter distances do not meet the necessary coverage and sensitivity requirements needed for effective detection in fire scenarios. Thus, the choice of 50 feet aligns with industry standards, ensuring that the smoke and heat detectors can collaborate effectively in identifying fire incidents, providing a higher level of safety in environments where they are installed.