What is the difference between a smoke detector and a heat detector?

Smoke detectors and heat detectors serve distinct purposes in fire detection, which makes the second option the correct one. Smoke detectors are designed to identify smoke particles produced during combustion. They work by detecting the presence of these particles in the air, enabling them to respond to a fire early, even before flames are fully engaged. This early response is crucial for ensuring occupant safety and minimizing property damage.

On the other hand, heat detectors function by monitoring temperature changes in their environment. They activate when a predetermined temperature threshold is reached or when there is a rapid increase in temperature, indicating that a fire may be occurring. These devices do not respond to smoke and are therefore less sensitive to fire in its early stages compared to smoke detectors.

The other options do not accurately capture the fundamental differences between these two types of detectors. For instance, while costs can vary due to factors like brand and installation requirements, the expense of smoke detectors relative to heat detectors is not a core characteristic differentiating their functionalities. Similarly, heat detectors are applicable in various settings, including both commercial and residential buildings, making it incorrect to say they are only used in commercial environments. Lastly, claiming that there is no difference in functionality overlooks their distinct operational mechanisms and the types of fires they can best detect.