Why are photoelectric smoke detectors recommended for smoldering fires?

Photoelectric smoke detectors are particularly recommended for detecting smoldering fires because they are designed to respond effectively to the low-level smoke that such fires produce. Smoldering fires tend to emit larger smoke particles compared to flaming fires, which produce smaller particles. Photoelectric detectors use a light beam that is scattered by smoke particles, allowing them to detect smoke at lower concentrations. This makes them highly suitable for identifying smoldering fires, such as those that might occur with materials like upholstery or mattresses.

The sensitivity of photoelectric detectors to these larger particles is their main advantage in this context, making them more efficient for early detection of smoldering fires, which can develop slowly and may not produce an immediate, large flame or significant heat. This early detection is crucial for ensuring safety and allowing for timely responses to prevent the situation from escalating.