A key aspect of fire protection is to identify a developing fire emergency in a timely manner, and to alert the building's occupants and fire emergency organizations. The fire detection and alarm systems provide a means to identify a developing fire through either manual or automatic methods and alert building occupants to a fire condition and the need to evacuate.

Fire detection in any building means the monitoring of surroundings to check for any changes that give an indication of a fire. This is done by detecting the presence of smoke, sudden rise in temperature and/or detecting any presence of flame. The equipment used are:

  • Smoke Detectors
  • A smoke detector is a device that senses the presence of smoke in a building and warns the occupants, enabling them to escape a fire before succumbing to smoke inhalation or burns. A smoke detector will detect most fires much more rapidly than a heat detector. Smoke detectors are identified by their operating principle.

  • Heat detectors
  • Heat detectors are normally used in environments where a smoke detector would generate false alarms - such as kitchens or shower rooms. They are generally located on or near the ceiling and respond to the thermal energy of a fire. They respond either when the detecting element reaches a predetermined fixed temperature or to a specified rate of temperature change. In general, heat detectors are designed to operate when heat causes a prescribed change in a physical or electrical property of a material or gas.

  • Flame detectors
  • A flame detector responds either to radiant energy visible to the human eye (approx. 4000 to 7700 angstroms) or outside the range of human vision. Similar to the human eye, flame detectors have a 'cone of vision', or viewing angle, that defines the effective detection capability of the detector.
    Due to their fast detection capabilities, flame detectors are generally used only in high-hazard areas, such as fuel-loading platforms, industrial process areas, hyperbaric chambers, high-ceiling areas, and atmospheres in which explosions or very rapid fires may occur. Because flame detectors must be able to 'see' the fire, they must not be blocked by objects placed in front of them. The infrared-type detector, however, has some capability for detecting radiation reflected from walls.