Susan Hansen, Extension Educator Colfax County

Thousands of carbon monoxide poisonings occur each year.

 

Homes today are built tighter and save substantial amounts of energy and expense. Home owners can save money on energy bills by applying caulking around the windows and doors, using weather stripping, insulating wall or attic spaces, adding storm windows and requesting airtight construction on remodeling projects.

 

These measures, coupled with air-consuming appliances such as the fireplace and the conventional furnace, affect pressure balances and can cause carbon monoxide problems in the home. Air pressure, ventilation, winds, moisture, and door and window opening/closing are additional factors that affect pressure balances and are potential carbon monoxide problems.

 

Virtually any ventilation system has the potential to create negative pressure, or the situation of more air leaving than is entering the home.

 

Carbon monoxide is produced when carbon-based fuels, such as gasoline, natural gas, wood, or coal, burn incompletely. CO is an odorless, tasteless, colorless gas that is difficult to detect. When CO combines with oxygen, it can be absorbed through the lungs into the bloodstream where it inhibits oxygen-carrying abilities of blood. High concentrations can be fatal.

 

Home poisonings occur when venting systems fail to remove combustion gases. A blocked chimney is the most obvious cause of vent failure. A less obvious failure occurs when the flow out of a chimney reverses. This condition is called back drafting.

 

Gas appliances such as furnace and water heater, kitchen and bathroom exhaust fans, clothes dryers and fireplaces consume household air during operation. To work properly, they require an adequate supply of air. A roaring fire in an open fireplace can use 10 times as much air as a furnace.

 

While a recommendation for good indoor air quality is to run the kitchen and bathroom exhaust fans for 20 minutes after use, their use for a prolonged period of time in a tight house with no make-up air supply can starve a furnace of air.

 

Energy-efficient homes today may not have enough air necessary for natural draft combustion appliances to operate properly.

 

The intensity of this problem is increased by the use of fireplaces and advanced ventilation exhaust fans for the kitchen and bathroom. The trend toward these source-specific ventilating fans is growing because of their quiet operation and concern about air quality pollutants.

 

Potential problems can be avoided by choosing a furnace or water heater that has the combustion process completely sealed from the home’s indoor air reservoir. Combustion air should be drawn from outside the house through a dedicated entrance only for that specific appliance. To avoid indoor air pollution, don’t even consider getting unvented appliances.

 

As with electrical and plumbing loads, the appliance should be properly sized for the home’s heating needs. A qualified and certified professional, trained in the system, air flow and mechanical structure of home and appliances, can help if there’s a problem. Also, consider installing carbon monoxide monitors.