You would think that the controversy with carbon monoxide detectors would be a thing of the past, but if you did, you would be wrong. Carbon monoxide detectors are now required in all homes in California per the Uniform Building Code. We often must install them when we install a new heating and air conditioning system. Home inspectors flag them when the home is sold. They are here to stay.
Carbon monoxide detectors are a very good way to be notified that your furnace has a crack in the firebox, but they simply won’t work very well until you are dead. There are no carbon monoxide detectors that I have found available to the public that detect the levels of carbon monoxide that start to harm people for sale. None—zip. Try reading the warnings and instructions on a carbon monoxide detector. In a nutshell it states that they don’t work at lower CO2 levels. If they go off, get out, you are in danger.
Most carbon monoxide detectors are being installed as combination units with smoke detectors. All of the units get installed in the home wired in series. When one goes off they all go off. The problem with the combination detectors is that CO2 is heavier than air and sinks to the floor and smoke rises to the ceiling. So if your Co2 detector is on the ceiling it will go off if the furnace is what is producing it because it will be quite hot when it leaves the supply register, but if the air coming out the register gets to cool off it will drop to the floor and not set off the CO2 detector.
You need one at the floor level. There are models that plug right into an electrical outlet. This is perfect for an easy installation. You still need them at the ceiling level, so replace the smoke detectors in your home with combination units.
You will need a low level CO2 detector. We can get them now, but I am sure that manufacturers will open up their sales to the Internet in the near future (maybe already) for low level CO2 detectors to the public.