Which type of smoke detector is typically more effective at detecting smoldering fires?

Photoelectric smoke detectors are particularly effective at detecting smoldering fires due to their design and operating principles. These detectors utilize a light source and a sensor that measures light levels. When smoke from a smoldering fire enters the detection chamber, it scatters the light, triggering the alarm. This type of fire often produces larger particles and more smoke before bursting into flames, making photoelectric detectors well-suited for these conditions.

In contrast, ionization smoke detectors, while effective at detecting fast, flaming fires, are less responsive to the larger particles associated with smoldering fires. Combination smoke detectors, which include both ionization and photoelectric capabilities, may provide a balance but might not be as specialized for smoldering fires as the photoelectric variant. Heat detectors function on temperature changes and are typically not designed to respond to smoke at all, which limits their effectiveness in the early detection of smoldering fires. Therefore, for detecting smoldering fires, photoelectric smoke detectors are the most reliable choice.