HAVE YOU CHECKED YOUR SMOKE ALARMS LATELY?
SMOKE ALARM/DETECTOR AND SYSTEM SERVICE, CHECK, TROUBLESHOOTING, REPAIR AND INSTALLATION
DID YOU KNOW?
Most new homes have hard-wire smoke alarms/detectors and require an electrical professional. The fact is, new homes require hard-wire smoke alarms/detectors to be interconnected, so that if one smoke alarm is activated, all alarms will sound the smoke alarm signal.
We specialize in smoke alarm and smoke alarm/detector systems installation as well as keeping your family safe, by staying to code. It is also smart to have your smoke alarm system checked yearly and replaced every five to ten years.
Smoke alarms provide an early warning of a fire, giving people additional escape time. In 2009-2013, smoke alarms sounded in more than half (53%) of the home fires reported to U.S. fire departments.
Three of every five home fire deaths resulted from fires in homes with no smoke alarms (38%) or no working smoke alarms (21%).
The death rate per 100 reported home fires was more than twice as high in homes that did not have any working smoke alarms compared to the rate in homes with working smoke alarms (1.18 deaths vs. 0.53 deaths per 100 fires).
In fires in which the smoke alarms were present but did not operate, almost half (46%) of the smoke alarms had missing or disconnected batteries.
Dead batteries caused one-quarter (24%) of the smoke alarm failures.
To read more visit: National Fire Prevention Association
Alarm Types: There are two main types of smoke alarms/ detectors: ionization smoke detectors and photoelectric smoke detectors. A smoke alarm uses one or both methods, and sometimes a heat detector to warn of a fire. The devices may be powered by a 9-volt battery, lithium battery, or 120-volt house wiring.
Ionization Detectors: Ionization detectors have an ionization chamber and a source of ionizing radiation. The source of ionizing radiation is a minute quantity of americium-241 (perhaps 1/5000th of a gram), which is a source of alpha particles (helium nuclei). The ionization chamber consists of two plates separated by about a centimeter. The battery applies a voltage to the plates, charging one plate positive and the other plate negative. Alpha particles constantly released by the americium knock electrons off of the atoms in the air, ionizing the oxygen and nitrogen atoms in the chamber. The positively-charged oxygen and nitrogen atoms are attracted to the negative plate and the electrons are attracted to the positive plate, generating a small, continuous electric current. When smoke enters the ionization chamber, the smoke particles attach to the ions and neutralize them, so they do not reach the plate. The drop in current between the plates triggers the smoke alarm.
Photoelectric Detectors: In one type of photoelectric device, smoke can block a light beam. In this case, the reduction in light reaching a photocell sets off the smoke alarm. In the most common type of photoelectric unit, however, light is scattered by smoke particles onto a photocell, initiating an alarm. In this type of detector there is a T-shaped chamber with a light-emitting diode (LED) that shoots a beam of light across the horizontal bar of the T. A photocell, positioned at the bottom of the vertical base of the T, generates a current when it is exposed to light. Under smoke-free conditions, the light beam crosses the top of the T in an uninterrupted straight line, not striking the photocell positioned at a right angle below the beam. When smoke is present, the light is scattered by smoke particles, and some of the light is directed down the vertical part of the T to strike the photocell. When sufficient light hits the cell, the current triggers the smoke alarm.
Which Method is Better?
Both ionization and photoelectric detectors are effective smoke sensors. Both types of smoke detectors must pass the same test to be certified as UL smoke detectors. Ionization detectors respond more quickly to flaming fires with smaller combustion particles; photoelectric detectors respond more quickly to smoldering fires. In either type of detector, steam or high humidity can lead to condensation on the circuit board and sensor, causing the alarm to sound. Ionization smoke detectors are less expensive than photoelectric smoke detectors, but some users purposely disable them because they are more likely to sound an alarm from normal cooking due to their sensitivity to minute smoke particles. However, ionization smoke detectors have a degree of built-in security not inherent to photoelectric smoke detectors. When the battery starts to fail in an ionization smoke detector, the ion current falls and the smoke alarm sounds, warning that it is time to change the battery before the detector becomes ineffective. Back-up batteries may be used for photoelectric smoke detectors.