Optical Smoke Alarms

An optical smoke alarm detects smoke by light scattering, the principle Apollo states for its XP95 55000-600APO and Discovery 58000-600APO detectors: smoke entering the chamber deflects a light beam onto a sensor and triggers the alarm. It is also called a photoelectric alarm, and the Aico Ei146e and Espire ES1SL are domestic optical alarms in this range.

Choose optical: every alarm and detector in this range is optical (photoelectric), and optical alarms are widely fitted in hallways, landings and living areas. Heat alarms sit alongside them in kitchens, where cooking fumes would trigger a smoke alarm, so check the guidance for your property type before fitting.

Not quite. A smoke alarm is self-contained: it senses smoke and sounds its own sounder, as the Aico and Espire alarms do. A smoke detector reports to a fire alarm panel, which operates the sounders, as the Apollo, C-TEC, Nittan and Hochiki heads here do.

Yes. Aico RadioLINK+ alarms such as the Ei650iRF interlink by radio, with no cable between rooms, and mains alarms such as the Ei146e can be hard-wired together. Either way, when one alarm detects smoke, every interlinked alarm in the property sounds.

A 10-year alarm, such as the Aico Ei650i, has a sealed lithium battery designed to power it for its whole service life, so the battery is never changed. When the alarm reaches the end of its life, the whole unit is replaced.

A multi-sensor alarm combines optical smoke sensing with heat sensing in one head, so it responds to smoke and to a rise in temperature. The Aico Ei660i, the ESP CSD2 and the Nittan EV-PH, which adds 54°C A1R heat detection, are multi-sensor units in this range.

Yes. The C-TEC CA416 CAST addressable optical smoke detector, the Apollo Discovery 58000-600APO and the Nittan EV-P report individually to a fire alarm panel loop, so the panel shows exactly which head has operated. An addressable detector needs a panel that uses the same protocol.

Yes. The ESP PSD212 is a 12V optical smoke detector and the ESP PSD2 a 24V version, and the ESP CSD2 combines optical smoke with fixed heat detection. Choose the voltage that matches the panel or power supply the detector will connect to.