Q. Our house has an attached two-car garage and I have been told that I should get a carbon monoxide detector. My question is where should I install it? We have smoke detectors located in each hallway, upstairs and down, and one at the foot of the basem ent steps. Should there be a CO detector at each of these locations or just one in the garage itself?
A. The location of carbon monoxide detectors is not as critical as smoke detectors as smoke is heat driven naturally to the higher levels of a room or a home which is why your smoke detectors are located where they are.
Like smoke detectors, having just one CO detector is not enough. If you have any potential CO sources in the home then you should have CO detection and more than one.
Carbon monoxide sources include any fossil fuel burning devices, including gas or oil furnaces, gas or oil water heaters, gas stoves, gas fireplaces or heaters, wood burning fireplaces or stoves and attached garages. I include wood burning fireplaces be cause some people have been known to do some pretty dumb things with their fireplaces that can cause CO poisoning such as burning charcoal briquettes for grilling in the fireplace then closing off the damper prior to the coals burning out-- they are big CO producers. We’ve had problems with people misusing gas powered generators during power outages-- a situation where no power to the wall outlet in which the CO detector is plugged disables the alarm should they even have one.
Carbon monoxide poisoning symptoms include headache, fatigue, shortness of breath, nausea and dizziness. Some folks have misdiagnosed these symptoms thinking it was the flu with tragic results. Carbon monoxide levels are measured in parts per million of air (ppm). Symptoms can begin in air that is only 70ppm. Increase that to 200ppm and you can die. Compare that with oxygen in normal air at 200,000ppm. So it doesn’t take much CO to create a dangerous condition.
Gas appliances and heating system flues and chimneys should be checked annually and since the weather is starting to cool now is the time. I’ve seen vents and flues clogged with bird nests built over the summer.
Many of the CO detectors on the market plug into the wall using the house current for a power source and normally most outlets are near the floor. The reality is that carbon monoxide mixes with the air in such a manner that if the thing detects properly and if the CO levels are approaching critical levels it's going to sound off almost no matter where it is. I tell folks to put one in the master bedroom as that's where people spend most of their time and generally if CO is going to get you, it's going to happen while you're sleeping.
I wouldn't bother putting a CO detector in a garage. You don't live in the garage and cars put out CO in large amounts which will cause the thing to sound when it's not really needed. One shouldn't start and warm a car in a closed garage and even a car that's hot from running will put off some CO after it's shut off for a little while. Garages are naturally leaky at the doors and unless a car is left running in a closed garage, the residual CO will vent away after a while.
Remember carbon monoxide detectors are not a lifetime product and their effectiveness diminishes over time. Having multiple old CO detectors can be just as bad as having none. Research the lifespan of the detectors you buy and replace them when they exp ire.
Recent building codes require that smoke detectors be located inside of each sleeping area. Research of the sad statistics kept on fatalities in the home showed that if a fire occurred inside of a room in which a person was sleeping and the door to the room was closed, the person in the room was very likely not to survive long enough to respond to the alarm in the hall so the rule was tightened. It's a good idea for you to follow suit and buy some battery operated smoke detectors and stick them in the bedrooms. Some smoke detectors now come sealed with long-term batteries that last for ten years. Some manufacturers even combine both smoke and carbon dioxide in the same unit.
Both CO detectors and smoke detectors have proven themselves as genuine lifesavers and are the cheapest form of life insurance you can buy so don't skimp-- get the best you can buy. The old phrase "The life you save may be your own" applies here.