● Fire system design considers both fire and false alarm risks.

● Detectors are selected based on the area's nature and associated risks.

● Different detector technologies are used to balance fire detection and false alarm rejection.

● Single-sensor detectors (e.g., optical smoke, heat detectors) are chosen for specific fire risks.

● Multi-sensor detectors can detect fires earlier and reduce false alarms.

● Detector choices are made during design and may be revised during commissioning or maintenance.

● Poor recording of detector choices and rationale can cause confusion during maintenance.

● Visual inspection helps test single-sensor detectors; multi-sensor detectors require understanding of their settings and configuration.

● Annex E aids in selecting and documenting detector types, sensitivity, and settings.

● Table E.1 provides a template for documenting risks, decisions, and rationale for detector choices.

● A flowchart in Figure E.1 guides the detector selection process and completion of Table E.1.

● Further guidance on completing Table E.1 is provided, including references to BS 5839-1.

Figure E.1 — Flow chart for the selection of detector and application verification

Table E.1 — Detector selection

Protected area/type of areaA)

Choose from:

Other: please specify

Hotel bedroom en-suite

Hotel bedroom non en-suite

Hotel suite

Bedroom dormitory style

Office cellular

Office open plan

Kitchen (main)

Kitchenette

Restaurant/ Canteen Corridor

Escape route

Reception area Lobby

Workshop (clean)

Workshop (moderate) Workshop (dirty)

Warehouse / storage

Predominant use of areaB)

Choose from:

Sleeping

Cooking

Unoccupied

Storage non-flammable

Storage flammable General office work Meetings

Circulation route

Escape route

Manufacturing

Manufacturing (hot works)

Assembly

Table E.1 — Detector selection (Continued)

Fire phenomenonC)

Choose from:

Smoldering white smoke

Smoldering dark smoke

Smoldering changing to flaming

Flaming (clean burn)

Flaming (dirty)

Other: please specify

False alarm risk(s)D)

Choose from:

None

Steam

Toaster

Oven usage

Cooking

Dust

Smoking

Aerosol spray

Hot works

Detector typeE)

Choose from:

Optical

Heat(static)

Heat (RoR)

Ionization

Multi-sensor

Optical/ Heat

Heat/CO

Optical/CO

Optical/ Heat/CO

Optical beam

Linear heat

ASD Class C

ASD Class B

ASD Class A

Flame

Video

CO

Table E.1 — Detector selection (Continued)

Detector settingF)

Please specify detail of detector setting(s)

Certificated mode(s) chosen?G)

Choose from:

Yes

No

Acceptable to interested parties?H)

Choose from:

Yes

No – then specify

Fire strategy met?I)

Fire strategy met?I)

Yes

No – then specify

Detector type/ setting choice rationaleJ)

Please specify in detail

Comments/

ActionK)

Details as appropriate

System Category and Settings (A):

Align the protected area with the system category (Clause 5). Reevaluate and record settings for different modes (e.g., day/night).

Anticipated Use (B):

Identify the main uses of the protected area, covering primary functions.

Fire Risks (C):

List main anticipated fire risks by type or cause (not exhaustive).

False Alarm Risks (D):

Identify predominant false alarm causes (not exhaustive). Refer to Clause 35 for minimizing false alarms.

Detection Types (E):

Consult Clause 21 for information on and selection of detection types.

Detector Settings (F):

Consider different settings (response speed, delays, sensitivity) and other risks (e.g., evacuation strategy) when choosing settings.

Non-Certificated Modes (G):

Avoid using detector modes not certified to BS EN 54 standards. If used, document the decision, agreed in writing by interested parties, and provide manufacturer information on non-compliance.

Interested Parties (H):

See Clause 6 for defining relevant interested parties.

Future Changes (I):

Understand implications of future changes to detection types or settings to ensure ongoing support of the fire strategy.

Decision Reasoning (J):

Document the rationale for selecting detector technology, type, setting, and sensitivity.

Additional Information (K):

Provide any other relevant information or required actions related to detector selection.

To assist in completion of the fire phenomena column in Table E.1, the following summary of individual sensor detection performance (as found within point type fire detectors) is provided in Table E.2. It also shows some indication of how a typical multi-sensor detector can be used to improve detection.

Table E.2 — Example fire risks

To assist in completion of the false alarm risks column in Table E.2, the following summary of typical causes of false alarms and how individual sensors respond to them is provided in Table E.3. It also shows some indication of how a typical multi-sensor detector can be used to improve false alarm rejection.

Table E.3 — Example avoiding false alarms

Screenshot (30).png

A) Multi-sensor detector responses could be a combination of the single-sensor responses, but the behaviour of a multi-sensor is dependent on the manner in which the sensors are combined within the detector. The combination of sensors within a multi-sensor detector could provide an enhancement to performance overall and cannot be considered to be the linear sum of the individual sensor responses. The response of multi-sensors are not common across all detector manufacturers, due to differences in construction and internal algorithms. The response of a chosen multi-sensor, including its mode and settings, should be properly understood to ensure that the risks are adequately covered. This table shows some typical examples of multi-sensor responses and does not represent an exhaustive list of all possible sensor combinations and algorithms.

Annex E (informative)The selection and application of fire detectors