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Regulations for fire detectors

Differentiation of detectors according to their mounting position

The distinction between ceiling detectors and lintel detectors mentioned hereunder is only due to their installation position. They are not different detectors.

The position in which the detectors are installed (on the ceiling or directly on the lintel) depends, among other aspects, on the distance between the top edge of the door and the ceiling, as well as the type of fire protection closure.

Ceiling detectors

  1. Ceiling detectors should be installed directly below the ceiling undersurface above the clear door opening – at least one on each side.
  2. The horizontal distance of the detectors from the wall should be, at least, 0.5 m and 2.5 m at most.
  3. If the distance between the ceiling and the clear opening is more than 5 m, detectors should be installed on cantilever arms with a length of 0.5 m, and at least 3.5 m above the opening.
Installation position of ceiling detectors for hold-open system

Illustration to point 2

Hold-open system - ceiling detector on cantilever arm

Illustration to point 3

Cantilever arm for fire detector - 040575

Cantilever arm, part no. 040575

Special regulations for ceiling detectors on suspended ceilings

If suspended ceilings or false ceilings are installed, the following points must be clarified:

  • Is the suspended ceiling permeable to smoke?
  • Is the suspended ceiling impermeable to smoke?
  • Where does the highest smoke concentration arise first ?
Ceiling detector on suspended ceiling

The suspended ceiling is smoke-impermeable or classified in terms of fire protection
> Ceiling detector is installed on the suspended ceiling

Ceiling detector on raw ceiling

The suspended ceiling is smoke-permeable
> Ceiling detector is installed on the bare ceiling

Lintel detector

  1. If the bottom part of the ceiling on one or both sides of the opening is more than 1.0 m above the top edge of the clear opening, at least one additional lintel detector must be fitted directly to the wall above the clear door opening and max. 0.1 m above the bottom edge of the lintel. For an easy installation, DICTATOR supplies a mounting bracket (part no. 040570).
  2. If the clear opening is not wider than 3.0 m and is closed by a hinged door, it is enough to install only one lintel detector instead of two ceiling detectors if the bottom part of the ceiling is no more than 1.0 m above the upper edge of the opening to be protected on both sides.
Installation position for lintel detector

Illustration to point 1

Installation position for lintel detector

Illustration to point 1, exact installation position
Installation accessory: bracket (part no. 040570)

Special regulation for hinged doors

Lintel detector instead of ceiling detector

Illustration to point 2
Here it can be chosen between 1 lintel detector or 2 ceiling detectors

Smoke detector on double doors

Illustration to point 2
In double hinged doors, both lintel and ceiling detectors must be installed above the active leaf.

Detection range / coverage radius of fire detectors

It is assumed that each fire detector is capable of detecting fire or smoke in an area of 2 m in each direction.

If the width of the door opening is greater than 4 m, additional detectors or detector pairs are required:

  • Opening width > 4 metres: double number of detectors
  • Opening width > 8 metres: triple number of detectors
  • Opening width > 12 metres: four times the number of detectors
  • etc.

Maximum detection range per detector

Max. detection range for fire detector

The detector detects fire/smoke in a range of 2 metres in all directions. With an opening width of up to 4 metres, the simple number of ceiling and lintel detectors is sufficient. If the opening width is larger, more detectors must be installed.

Maximum distance between two detectors

Additional ceiling and lintel detectors

If, for example, the opening width is greater than 4 metres but less than 8 metres, double number of lintel and ceiling detectors must be installed. The distance between individual detectors must not exceed 4 metres.

Decision diagram for determining the required number of fire detectors

With the help of the decision diagram below, it can be easily determined how many fire detectors are needed and whether they should be lintel or ceiling detector or both!

Decision tree for fire detectors

Additional detectors are required according to EN 14637 for opening widths greater than 4.0 metres!

  • Opening width more than 4 metres -> double number of ceiling and lintel detectors are required
  • Opening width more than 8 metres -> triple number of ceiling and lintel detectors are required
  • Opening width more than 12 metres -> four times the number of ceiling and lintel detectors are required

Smoke or heat detector?

Smoke detectors should be used whenever possible.

If smoke or dust occurs during rutine working or manufacturing processes and there is a danger that smoke detectors may trigger false alarms, heat detectors should be used.

Heat detectors should not be used on smoke closures, as smoke is not detected by them and thus the smoke protection function cannot be fulfilled.