Which type of smoke detector is recommended for use in residential sleeping areas?

Photoelectric smoke detectors are recommended for use in residential sleeping areas primarily because they are more effective at detecting smoldering fires. These types of fires typically produce a significant amount of smoke before they burst into flames, making photoelectric detectors particularly well-suited for identifying such situations early. They work by using a light source and a sensor to detect smoke particles, which can lead to quicker alarms in situations where fires start slowly, such as with burning mattresses or upholstery.

In contrast, while ionization smoke detectors are generally effective for fast-flaming fires, they may not respond as quickly to the smoke from smoldering fires, which can be a critical risk in sleeping areas where occupants may be unaware of a fire situation. Combination detectors offer benefits from both technologies, but in the context of sleeping areas focused on early warning in all conditions, photoelectric detectors are specifically recommended for their sensitivity to smoldering fires. Optical smoke detectors, while functioning on a similar principle to photoelectric detectors, are not typically referenced as standalone options for residential sleeping areas, hence the focus on photoelectric for this question.