What type of fires are photoelectric smoke detectors most responsive to?

Photoelectric smoke detectors are specifically designed to respond effectively to smoldering fires. This type of fire typically produces a large amount of smoke and tends to burn slowly without producing significant flames. The photoelectric sensing technology works by detecting the smoke particles present in the air, which disrupt the light beam inside the detector, triggering the alarm.

In contrast, other types of fires, such as flaming fires, generate less smoke relative to their flame output and may not be detected as quickly by photoelectric devices. Electrical and grease fires can also produce flames quickly, which may better suit ionization smoke detectors that are more responsive to fast-flaming fires. Therefore, understanding the characteristics of smoldering fires clarifies why photoelectric detectors are optimized for this scenario.