Smoke and Carbon Monoxide Alarms
Types of Carbon Monoxide Detectors
A "silent killer," carbon monoxide (CO) gas is odorless, tasteless, and invisible. Carbon monoxide poisoning is one of the leading causes of poison related deaths in America. CO gas is released into the air when burning wood, oil, propane, charcoal, or natural gas. In most situations, it dissipates before it becomes concentrated enough to pose a health risk, but gas leaks in your home, TV, or garage can be fatal. Carbon monoxide detectors alert you to dangerous levels in the air using one of three types of sensors:
- Biometric detectors use gels that absorb carbon monoxide. Once a certain threshold is met, an alarm sounds.
- Metal oxide detectors have silica chips that trigger an alarm when CO is detected.
- Electrochemical sensors use electrodes in chemical solutions that sense changes in electrical currents caused by the presence of carbon monoxide. When CO is detected, the alarm sounds.
Types of Smoke Detectors
The two types of smoke detectors are ionization alarms and photoelectric alarms, though there are some combination smoke detectors that include both types of sensors because each is better at detecting a different type of fire.
- Ionization alarms use electrically charged partials to detect smoke and are faster at detecting flaming fires, such as a grease fire or a tipped over candle. Flaming fires spread quickly, filling a room or house with flames in minutes.
- Photoelectric smoke detectors use light beams to detect the presence of smoke and are faster at detecting smoldering fires, such as a smoking fireplace or burning roast. Smoldering fires fill a room with smoke with only small flames or no visible flame.
Where to Install Carbon Monoxide Detectors and Smoke Alarms
Industry experts recommended that CO detectors be placed on every floor of the building and the following rooms:
- 5-20 ft. from a furnace, water heater, or fireplace
- Living Room
- Laundry room
Most states require smoke detectors on each floor of a building in addition to the following rooms:
- Outside of sleeping areas
- Living Room
The overlap between where smoke and carbon monoxide alarms are required make combination smoke/CO alarms a smart purchase. In addition to this list, always check the local fire code as each state and municipality may have unique rules. For example, California is often the first to adopt more strict regulations, such as requiring tamper-proof smoke detectors.
Is Your Smoke Detector Still Effective?
Smoke alarms and carbon monoxide detectors become less effective over time. From 2009 to 2013, smoke alarms were present but failed to operate in 8% of reported fires, resulting in a 21% fatality rate. Even if the alarm sounds when tested, years of built up smoke, grease partials, dust, and other debris can coat the alarm's sensor and lessen its ability to detect a fire in a timely manner. Because of this, the National Fire Protection Agency (NFPA) recommends replacing the entire unit once every ten years even if you've been diligent about replacing the batteries.
Decade Long Protection: Tamper-Proof Smoke Detector
Never change the batteries again! First Alert carbon monoxide detectors and smoke detectors are now available with sealed 10-year Lithium batteries. California state law requires these tamper-proof designs for all smoke detectors and carbon monoxide detector replacements. When the low battery chirps, simply replace the unit for another decade of worry free protection. This is the best smoke detector for apartment buildings and rental homes as many states make the landlord responsible for upkeep, even if residents are the ones failing to replace the battery or disconnecting the unit to stop false alarms.
Should You Buy Battery Operated or Hard Wired?
Most importantly, check the regulations in your area. Homes built before 1992 generally aren't required to have hardwired smoke detectors, and California requires ten year tamper-proof battery operated alarms. Because hard-wired alarms can be connected, a fire on the first floor can trigger an alarm on the second floor, giving you more warning to get out of the house than if you're unable to hear the alarm over a TV or stereo. Just remember that hard-wired alarms have a backup battery that needs to be tested and periodically replaced as well. The backup battery is designed to keep power to the device in the event of a power-outage.
Interconnectivity and Retrofit Accessories
Alarms need to be mounted in locations to sound at the first sign of smoke or carbon monoxide. For elderly, sight or hearing impaired people, additional auxiliary warning devices can be mounted in places closer to the bed or easier to see from other places in the room. Relay modules can be used to activate these additional warning devices such as externally mounted bells, sirens, or stairway lighting.