What Are the Different Types of Smoke Detectors?

Types

• The U. S. Fire Administration (USFA) website advises that there are two types of smoke detectors sold for use in private homes. Photoelectric smoke detectors are the most expensive type, but they are efficient for detecting smoldering fires and are not as likely to trigger false alarms because of cooking smoke. Ion smoke detectors are cheaper but detect fires once they reach the point of breaking out into open flames. The Fire Safety Council explains that ion alarms use a small amount of radioactive material to measure the conductivity in air, which is changed by nearby combustion. Photoelectric detectors use a light beam that gets scattered when suspended combustion materials in the air get into the unit. Both are effective, according to the USFA, but you can increase household safety by getting one of each.

Similarities

• Photoelectric and ion smoke detectors have several similarities. Both are readily available in stores, and both come in battery-operated models or alarms that are hardwired into a home's electrical system. Many hardwired alarms include a battery backup system in case the fire causes a power outage. Battery powered photoelectric and ion smoke detectors both alert you when the batteries need replacement by making a periodic chirping sound.

Power

• Smoke detectors are powered by two different sources, according to the NFPA. Some use batteries while others are hardwired into a home's electrical system. Hardwired detectors are more reliable than their battery-powered counterparts, with 95 percent of electrically powered alarms sounding in a fire as compared to 75 percent of battery units. Smoke detectors with batteries are useless if their power source is not replaced regularly. The NFPA advises that 20 percent of smoke detector failures happen due to dead batteries, while only 8 percent of failures happen because of hardwired power problems.

Considerations

• Smoke detectors can be separate units, or they can be interconnected. Connected units all sound if one detects smoke in a certain area. Single units sound individually in the area where smoke is present. The NFPA reports that the Consumer Product Safety Commission cites interconnected smoke detectors as the most effective set-up, particularly if the units are located on every floor of a home. Multi-floor connected units warn all occupants about a blaze, even if it happens on a different story of the building.