What is more important, the type of alarm or the number?
The number of smoke alarms is important. Smoke alarms that are spaced farther apart may be farther from the fire, lengthening the time it will take for smoke particles to reach it. Installing several smoke alarms reduces the potential distance from the fire source and provides better coverage, so the most important thing is to install enough alarms in the proper locations. The distance from a fire can also change the smoke, and this is where the difference between the ionization and photoelectric smoke alarms becomes important. What can take place is called “smoke aging.” As smoke particles move away from the fire, the heat dissipates and the smoke cools. As smoke gets cooler, the smoke particles and coagulate into larger particles. The farther the distance from the fire to the smoke alarm, the cooler the smoke and the larger the smoke particles. Ionization smoke alarms are better at detecting smaller particles, while the photoelectric respond better to larger particles. In these situa
