HACKENSACK - Carbon monoxide. You can't see it. You can't smell it. It could kill you.
Most people know it's not a good idea to use their charcoal barbecue grill in the kitchen or to run their car or lawnmower inside their garage, even with the door open.
But, what about that furnace that has been pumping heat throughout the house in these below zero days and nights. It's heating the house well, so it probably is OK. You could be wrong.
That's what Shirl Calder of rural Hackensack found out the hard way. It almost ended her life.
Any combustible fuel furnace or appliance can produce carbon monoxide when the fuel isn't venting right or the burners aren't working efficiently. According to an Iowa State University Web site, having a blue gas or propane flame doesn't even ensure efficient, carbon monoxide-free burning.
This can happen whether your furnace or heater burns wood, natural gas, propane, oil, corncobs or any other fuel.
During incomplete combustion, part of the carbon is not completely oxidized, producing soot and carbon monoxide.
Incomplete combustion comes from insufficient mixing of air and fuel or insufficient air supply to the flame or insufficient time to burn or cooling of the flame temperature before combustion is complete, the Iowa University Biosystems and Engineering Web site states.
It can occur for a variety of reasons, including blocked heater vent system, blocked flue passage in heating appliances, downdrafting from the vent or chimney or cracked rusted heat exchanger.
You might have a carbon monoxide detection alarm in your house. If it isn't under five years old, don't count on it to work. Replace it.
These, like fire alarms, can only be expected to work within the warrantee period and if the battery is fresh. Fire alarms may be good up to 10 years, but carbon monoxide detectors have a maximum life span of only five.
The Consumer Protection Safety Commission reports on its Web site that more than 200 people in the United States die annually from carbon monoxide produced by fuel-burning appliances such as furnaces, fireplaces, cooking stoves, water heaters, clothes dryers and room heaters.
Several thousand people go to hospital emergency rooms annually for treatment for carbon monoxide poisoning.
Symptoms may include headache, fatigue, shortness of breath, nausea, dizziness, mental confusion or increased heart pain in people who already suffer from angina, the Consumer Protection Safety Commission reports.
The Environmental Protection Agency notes symptoms may be similar to those commonly associated with flu and other illnesses. If you suspect carbon monoxide poisoning, that agency emphasizes the importance of telling doctors, so they can check your blood for carbon monoxide levels.
Oxygen normally travels throughout a person's body through circulating blood. When carbon monoxide enters the body, it replaces oxygen in the blood stream, starving all vital organs, including the brain, of oxygen, the University of Iowa Web site notes.
This is what leads to disorientation commonly associated with more advanced carbon monoxide poisoning. Ultimately, it replaces oxygen throughout the body and causes death.
Gordy Nelson, owner of Advance Heating and Cooling of Backus, who replaced Calder's furnace, reported her furnace heat exchanger had cracked, reducing the furnace's efficiency and permitting carbon monoxide to circulate through her house.
He also found a downdraft from her chimney, accelerating the problem.
If you follow the recommendation to have your furnace checked annually before winter heating season, Nelson emphasized asking the service person to check all possible sources for furnace or heater failure.
This is especially important when the furnace was installed five or more years ago. The life span of existing furnaces in most homes today is 15 to 20 years, he said.
Annually checking the entire heating system is the safest measure homeowners and renters can take, Nelson said.
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