How to choose the right type of fire detector

Direct answer

The right fire detector for a location depends on the fire risk, the environment, and how quickly detection is needed — not on a single "best" device. As general guidance, optical (photoelectric) detectors respond well to smouldering, smoky fires; heat detectors suit areas where smoke detection would cause false alarms (such as kitchens or dusty areas); and multi-sensor detectors combine sensing elements to balance early detection against false alarms. The correct selection and placement for your premises must be made by a competent designer through the fire risk assessment and in line with the current BS 5839-1, not chosen from a general description alone.

Applies to

Products / Models: Hochiki Europe detector ranges (general guidance — confirm the exact model on its data sheet)
Firmware / Version: Not applicable
Region: UK / Europe
Standards: BS 5839-1 (selection and siting), EN 54 (detector types)

Why detector type matters

Different fires develop differently: some produce visible smoke early, others produce heat first.
The wrong detector type for the environment causes either slow detection or frequent false alarms — see How to reduce false alarms (unwanted fire signals).
Selection is part of system design, and is recorded in the design documentation along with the system category — see Fire alarm system categories explained (BS 5839-1: L, P and M).

The main detector families (general intent only)

Optical / photoelectric smoke detectors — respond well to the larger smoke particles of smouldering fires. A common general-purpose choice for circulation and living areas.
Heat detectors — respond to a temperature rise (or a fixed temperature) rather than smoke. Suited to environments where smoke or fumes are normal (for example kitchens, some plant rooms), where they reduce false alarms but detect more slowly.
Multi-sensor detectors — combine more than one sensing element (for example optical and heat, and in some models carbon monoxide) and process the signals together to improve early detection while resisting false alarms. See, for example, ACD-EN Addressable Multi‑Sensor: CO, Smoke & Heat Functions for how a specific model uses selectable response modes.
Specialised detectors — beam, aspirating (HSSD), flame and linear heat detection exist for specific applications and large or difficult spaces; these are design decisions for a competent designer.

How the choice is actually made

The detector type, location and spacing are determined by the fire risk assessment and a competent designer, taking account of the room use, ceiling height, ventilation and likely fire type.
BS 5839-1 gives recommendations on detector selection and siting; the design records which type is used where.
Do not change a detector to a different type (for example swapping a smoke detector for a heat detector to stop false alarms) without a competent person confirming it still meets the design and the standard.

When to contact technical support

If you need to confirm which Hochiki detector models suit a particular environment or are compatible with your system.
If you are experiencing false alarms and are considering whether the detector type is appropriate — investigate the cause with a competent person rather than changing devices in isolation.

Safety note

This article is general guidance for Hochiki Europe products. Installation, commissioning, maintenance and modification of fire detection and alarm systems must be carried out by a competent person in accordance with the applicable standards (for example BS 5839-1 in the UK) and the requirements of the relevant authority having jurisdiction. Always refer to the current product manual and data sheet for the exact model before carrying out any work.

References

BS 5839-1 (current edition) — detector selection and siting recommendations
EN 54 series — detector type definitions
Product data sheets for the specific detector models

Last reviewed: 2026-06-16 — Reviewed by: Takashi Ishikawa