Carbon Monoxide Poisoning: How It Can Accumulate in Your Home

Published on: February 5, 2015
Carbon monoxide monitor | AC Southeast®

The majority of people killed by carbon monoxide poisoning every year never realized there was something wrong. It’s a sobering fact that many of the 200+ yearly fatalities occur to people asleep in their beds. These residents turned in for the night totally unaware that dangerous levels of carbon monoxide (CO) gas were silently accumulating inside the home.

Carbon monoxide deaths and injuries result from exposure to colorless, odorless CO gas, which is a common by-product of combustion that occurs in gas-fired furnaces and stoves, as well as internal combustion engines. While trace amounts of carbon monoxide gas may be present in tightly-sealed homes with gas furnaces and appliances, once concentrations reach toxic levels, illness, unconsciousness and death ensue rapidly.

Here are some of the ways CO levels may quickly rise from the harmless to the fatal.

Improper Venting

Gas appliances and furnaces should be vented to the outdoors via approved vent ducts that are inspected annually. Vents obstructed by birds nests, leaves or other debris may cause combustion gases, including CO, to enter the home. Vent ducts that are deteriorating and leaking at the seams are another source of possible carbon monoxide poisoning.

Inadequate Maintenance

Components of furnaces and stoves, including the burners and heat exchanger, should be inspected annually for safe operation. Incomplete combustion resulting from dirty or plugged burners generates excessive carbon monoxide. A cracked heat exchanger may permit combustion by-products, including CO, to enter the airflow inside ductwork.


Under certain circumstances, vented combustion gases can be sucked back into the home if the house is excessively depressurized. This may be caused by ventilation fans drawing too much air out of the home or duct leakage that disrupts neutral indoor air balance.

No CO Detector

Carbon monoxide detectors should be installed on every level of the home, close to sleeping areas. Test CO detectors for proper function twice a year. If battery-powered, replace the battery per manufacturer’s instructions.

For more information on preventing carbon monoxide poisoning, contact AirConditioningSouthEast.com for help finding a contractor in the southeast U.S.