Which smoke detector should I use?

Not all fires are the same. Some fires smolder and smoke for hours before flaming up and some fires burn quick without much smoke.  It makes good sense to install an alarm with duel detection features.

The most popular type sold in the U.S. today is the Ionization alarm. This type monitors ‘ions,' or electrically charged particles in the air. Air molecules in a sample chamber are ‘ionized' by a radioactive source. This allows a small electrical current flow. Smoke particles entering the sensing chamber change the electrical balance of the air. When combustion (smoke) particles enter the alarm, they obstruct the flow of the current. An alarm is pre-programmed to sound when the current gets too low. Ionization smoke alarms respond first to fast flaming fires. A flaming fire devours combustibles extremely fast, spreads rapidly and generates considerable heat with little smoke. This alarm is best suited for rooms that contain highly combustible materials like cooking fat/grease, flammable liquids, newspaper, paint and cleaning solutions.

Photoelectronic alarms contain a light emitting diode (LED) which is adjusted to direct a narrow infrared light across the unit's detection chamber. When smoke particles enter this chamber they interfere with the beam and scatter the light. A strategically placed photodiode monitors the amount of light scattered within the chamber. When a pre-set level of light strikes the photodiode, the alarm is activated.Photoelectronic smoke alarms respond first to slow smoldering fires. A smoldering fire generates large amounts of thick, black smoke with little heat.

Photoelectronic models are best suited for living rooms, bedrooms and kitchens because they often contain large pieces of furniture, such as sofas, chairs, mattresses, counter tops, etc. which burn slowly and create more smoldering smoke than flames.

Photoelectronic smoke alarms are also less prone to nuisance alarms in the kitchen area than ionization smoke alarms.

I suggest the use of a duel detector that uses both the ionization and the Photoelectronic features. Together they should provide a home with maximum protection and an ample warning in the event of a fire.