Smoke detectors can save lives by warning people of fires in homes, businesses and public facilities. While smoke detectors are very effective in protecting people, some types of detectors sound false alarms when triggered by steam, dust or other particulate debris.
Types of Smoke Detectors
Consumers can choose between ionisation or photoelectric smoke detectors, or a combination of the two.
Ionisation smoke detectors have a chamber containing two plates that generate an electric current. If smoke interrupts that current, an alarm sounds. These tend to respond more rapidly in cases of high flames.
Photoelectric smoke detectors incorporate a light beam that shines into a receptor inside the devices. If smoke interrupts the beam in any way, the alarm sounds. These detectors respond quickest to slow-building, smouldering fires.
Triggering of False Alarms
The design of photoelectric smoke detectors makes them most susceptible to sounding false alarms. Just as smoke interrupts the light beam, tripping an alarm, steam or dust clouds that reach photoelectric smoke detectors before dissipating can cause the same result. Any airborne obstruction thick enough to break the light beam causes this type of alarm to sound.
Installation Locations to Avoid
Areas near or above stoves or ovens, where heavy steam or residual smoke could trigger false alarms in smoke detectors, should be avoided. Photoelectric detectors also should not be used near construction sites, wood shops or other areas where regular work kicks up dust and debris.
Smoke detectors should be placed on every level of a dwelling or building, in hallways and corridors outside of all sleeping areas and in all bedrooms. Installing the devices in the centre of ceilings can help keep detectors far enough away from steam and dust that vapours or clouds break up before reaching the photoelectric beams. Thick smoke, however, will not dissipate as fast and will trip the smoke alarm sensor, as it should.
Alternatives to Smoke Detectors
For areas near regular steam, harmless residual smoke or dust production, heat detectors are effective alternatives to smoke detectors. These devices sound alarms based on sharp changes in temperature, rather than the presence of smoke or other debris. Heat detectors are good choices for kitchens, construction sites and areas where chemicals, which flare up quickly during fires rather than producing heavy smoke, are stored.
Life Saving Statistics
Despite the possibility of false alarms from steam and dust, smoke detectors remain important and recommended tools for saving lives. Firesafety.gov reports that 3,000 people die in residential fires every year in the United States, and the majority succumb to smoke or other deadly gases. Meanwhile, National Fire Protection Association statistics show the death rate for every 100 reported fires was more than twice as high in homes without smoke detectors than at dwellings equipped with the devices. Simply put, smoke detectors provide the warning people need to clear out of buildings before flames and smoke become so intense that escape becomes impossible.