Optical smoke alarm
The most common causes of a false alarm are:
A likely source of this type of fire is in a principal habitable room (a frequently used room by the occupants of a dwelling for general daytime living purposes) from the careless disposal of smoking materials. Polyurethane foam found in some furnishings may ignite and begin to smoulder producing large particles of smoke. Because of this, optical smoke alarms are recommended in principal habitable rooms. However if the room is used by a heavy smoker, this could give rise to some false alarms from tobacco smoke.
As optical smoke alarms are less sensitive from fumes caused by toasting bread or frying or grilling food, they are also recommended where a principal habitable room is open plan with a kitchen, and in hallways and stairwells adjacent to kitchens, to reduce the amount of unwanted alarms from cooking fumes. Most unwanted alarms occur during cooking.
Optical smoke alarms should conform to BS EN 14604: 2005 Smoke Alarm Devices.
 Related articles on Designing Buildings Wiki
- Building regulations.
- Carbon monoxide detector.
- Combustion appliance.
- Fire and rescue service.
- Fire dampers.
- Fire detection and alarm system.
- Fire detector.
- Fire protection engineering.
- Fire safety design.
- Heat alarm.
- Intruder alarm.
- Ionisation smoke alarm.
- Multi-sensor alarm.
- Principal habitable room.
- Scottish building standards.
- Smoke detector.
- The causes of false fire alarms in buildings.
- The role of codes, standards and approvals in delivering fire safety.
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