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How Carbon Monoxide Detectors Work

Carbon Monoxide Detector Installation
Having your chimney inspected annually and cleaned when necessary can lower your risk of carbon monoxide poisoning.
Having your chimney inspected annually and cleaned when necessary can lower your risk of carbon monoxide poisoning.
© iStockphoto/Maciej Korzekwa

­In the United States, emergency rooms treat about 15,000 people for carbon monoxide (CO) exposure each year, and an average of 480 people die from carbon monoxide exposure annually [source: CDC]. Most nonfatal exposures happen in people's homes, which is why it's important to have a CO detector to go along with -- or as part of -- your smoke detector.

Before selecting a carbon monoxide (CO) detector, do a little research. Determine whether your local laws require you to have CO detectors of a particular type or configuration. You'll need to decide whether you'd rather have a battery-operated or plug-in detector. A plug-in unit goes into any wall outlet and can be moved to another room if necessary. But unless y­our plug-in unit has a battery backup, you're unprotected in the event of a power failure. This may not seem like a big deal in the case of temporary outages, but imagine a long power outage during winter. You may turn to a portable space heater or a wood stove to keep your home warm -- exactly the sort of fuel-burner that may release CO into the air.

Battery-operated units, on the other hand, are typically attached permanently to a surface in your home. This usually isn't a problem unless your detector mistakes other gases for CO, causing false alarms and prompting you to move the unit. Depending on the size of your home and the number and location of fuel-burning appliances, a combination of types may work best. Follow the manufacturer's instructions for placement, maintenance and scheduled inspection.

The National Fire Protection Agency (NFPA) recommends carbon monoxide detectors in several locations:

  • Outside sleeping areas
  • On each floor of the home
  • Anywhere else required by law

The NFPA also recommends using detectors that can be linked together so that one alarm sets off all the others, alerting the whole household.

Installing CO detectors is only one step in preventing carbon monoxide poisoning. Other important steps include:

  • Have furnaces and chimneys inspected every year and serviced as needed. Be sure to open the flue before lighting the fire.
  • Have gas-burning appliances installed only by a qualified professional. Follow all manufacturer's instructions carefully.
  • Use tools that burn fuel only in well ventilated areas.
  • Make sure furnace, water heater and dryer vents are kept clear of leaves, debris and snow.
  • Repair or replace any fuel-burning tools, like lawn mowers or chainsaws, that are not working properly.
  • Have your car's exhaust system inspected for leaks, and never idle your car in the garage.
  • Never use an oven as a heat source or use a grill inside your home.
  • Never use generators indoors.

Finally, test your carbon monoxide detector once a month -- it's your last line of defense against a malfunctioning stove or heater.