What is the distance of two fire alarm?

Question

what is the distance of two fire alarm? or what is range of fire alarm can detect?

Answer 1

The distance between "pull stations" or "manual fire boxes" is 100 -ft travel distance (effectively 200 -ft between 'pulls').

If you are discussing smoke detectors then the answer is 900 sq ft in the ideal 30-ft by 30-ft room or area.  Don't forget the 0.7 rule which also means that 0.7(30)=21-ft from the furtherest corner of the room.

As NFPA 72 (National Fire Alarm Code) states in the Appendix the coverage between smoke detectors can be increased in the corridors (based on width) to up to 42-ft.

Keep in mind that any "pockets" in the ceiling or air currents thru an area adversely affect the detector and should be taken into account when placing a detector.  This could be as simple as a HVAC diffuser (which NFPA 72 requires smokes to be at least 3-ft away from)

To answer your question in the most generic terms:

a pull station can be 200-ft apart

a smoke detector can detect 900 sq ft (based on specific circumstances)

Answer 2

The other answers confuse the detecting range of a fire detector, and the maximum travel distance to the nearest fire alarm box.

Heat detectors have areas of coverage that allow for up to 2500 square feet per detector.  Smoke detectors and smoke alarms are usually to considered to have areas of coverage of 900 square feet.  In a roughly square room, this would be 30 by 30 feet.  In a narrow space, such as a corridor, they can be as much as 42 feet apart.

If this is in a residential unit (not a whole apartment or condo building) those numbers should be OK.  If it is for any other use, it is best to consult with your fire authority.  They sometimes have special rules or interpretations.

Answer 3

The range of the average, fire marshal approved, smoke detector (which is what i think you mean) is 100-150 feet

Answer 4

it is 150-200 feet.

Answer 5

You should never be more than 200 feet from a fire alarm pull station in a building other than a residential occupancy.  Not sure what the second part of your question means.