Fire, smoke and alarms

Smoke is by far the most likely cause of death during a fire. It very rarely happens that people are actually killed by the flames. Smoke has a number of properties, some of which are lethal:

  • Depending on the flammable materials at the location, it consists of poisonous substances that may result in suffocation if inhaled.
  • During a fire, the air is usually extremely hot so when it is inhaled it can scorch the windpipe and lungs, possibly causing asphyxiation.


    Depending on the density of soot particles, smoke can be opaque causing people to become disoriented in an instant. Studies have shown that people’s evacuation speed can be reduced to zero if visibility falls below 50 cm.
  • Smoke can spread through a building extremely rapidly so the time available to exit the building safely is limited. The safe evacuation time depends on the location of the fire in the building in relation to the location of the occupant.


    As smoke is warm, it first rises to the ceiling of the room (or of the stairwell). The upper part of a space fills up first. The standard mandatory emergency exit signs can usually be found above doors, which means these are the first to be obscured. The temperature and visibility at floor level remain tolerable for the longest time. Pulsating light at floor level therefore dramatically improves orientation and reduces evacuation time. With smoke, every second counts so every appliance that can reduce evacuation time can be a life-saver.


The LightSaver Original has been designed for use with standard smoke alarms. Most smoke alarms that can be bought at DIY stores produce an audible signal of around 3100 Hz. The Original features a sensor that effortlessly picks up every signal in the bandwidth where this frequency occurs.


In situations where a fire alarm system is required (such as in buildings with 50 or more occupants) the alarm sound is a produced by a slow-whoop. In the Netherlands, this type of siren is required to produce a sound in the 500 to 1200 Hz range. This sound range does not fall within the listening frequency of the Original. However, a variant of the LightSaver that will be able to recognise this siren is currently under development.