Sometimes called the "silent killer," carbon monoxide (CO) is an invisible, odorless gas that can cause brain damage and fatality when inhaled. The danger is significant enough that building codes are increasingly requiring that carbon monoxide detectors be installed in homes.
CO detectors are small electronic devices that monitor the CO level within a home. They’re designed to alert the homeowner when the CO level has begun to rise over a period of time and sound the alarm before a healthy adult would experience any CO-poisoning symptoms, which include fatigue, headache and nausea. Using a CO detector is the only accurate way to know how much CO is present in a home's indoor air on an ongoing basis.
CO detectors have additional features, too, including backlighted displays for easy reading in low light; digital displays that update every 15 seconds to show the CO level in the home; peak-level memory to indicate the highest level of CO in the home; and voice warning, which announces when CO is a threat in addition to sounding the traditional alarm.
The National Fire Protection Association recommends that a CO detector be centrally located outside of each separate sleeping area. For added protection, install CO detectors on every level of the home. When locating the units, make sure each is at least 15 feet from fireplaces and flame-producing appliances to prevent false alarms. Because CO is slightly lighter than air and also because it may be found with warm, rising air, it’s best to place a detector on the wall about 5 feet above the floor. The detector may be placed on the ceiling but shouldn't be covered or obstructed.
Carbon monoxide is naturally present in low levels in the air. It’s also formed by incomplete combustion from any flame-fueled device. Examples in the home include ranges, ovens, clothes dryers, furnaces, fireplaces, grills, space heaters, vehicles and water heaters. When appliances and vents work properly and there’s enough fresh air in a home to allow complete combustion, the trace amounts of CO produced aren’t typically dangerous.
Some household situations, however, can cause CO to rise to dangerous levels. The most common is a vehicle left running in an attached garage, which can allow CO to seep into the living space through vents and doors. Malfunctioning appliances are another common cause. For example, the heat exchanger on a furnace may crack without any indication to the homeowners, and CO can leak into the home.
A third common problem is an improperly vented fireplace, wood-burning stove or charcoal grill. Even a chimney blocked by debris or snow can cause CO buildup. Finally, in today's tightly sealed homes, fresh air can be scarce, and as a result several gas appliances running at the same time and competing for that limited fresh air can cause incomplete combustion and produce CO even if the appliances are in good condition.
Follow these easy tips to refresh and recharge your home this spring.