So you just bought a carbon monoxide detector to put in your home. The most common response would be to plug it into the electrical socket near the ground. Stop right there though. You just made a crucial mistake that many other people make when choosing the location to mount their carbon monoxide detector.
It is known that some companies recommend mounting their units near the floor, but in general it is a potential risk due to the chemical properties of carbon monoxide. The key point that we want to focus on is the specific gravity of CO which is 0.966. Compared to the air we breathe (1.0), carbon monoxide is slightly lighter which means it will rise. Having a carbon monoxide detector mounted near the ground means there is the possibility that it may not detect CO when it is present in your home. Consequently, you will want to mount carbon monoxide detectors on the ceiling the same way you would mount a smoke alarm.
Additionally, here are some other guidelines you should follow when choosing a mounting location. You will want to keep CO detectors out of bathrooms or any other humid areas. You will also want to place them at least 15 feet away from heating or cooking appliances. Placing a CO dectector near a furnace may also set off false alarms since these devices are known to emit a small amount of carbon monoxide upon start-up.
This except from: “The Answer Man”.Belleville News-Democrat. 12 Feb 2007, Final Ed.: C8