I am learning this firsthand unfortunately. Christmas eve an unexplained failure of the natural gas-fired boiler in our house somehow began an acute Carbon Monoxide event that culminated around 6am. We thought it was food poisoning for TWO DAYS while it abated. This made 5 adult family members, my baby and my unborn baby, very very sick -- for days now. We could end up regretting this the rest of our lives. Skipping the ugly and sad personal details, I want to emphasize how important it is to have a properly designed heat and gas appliance system. It seems stupid now, but we did not have a Carbon Monoxide detector in the house despite having a monitored security and smoke detection system. While that is the life or death difference, there is more to consider for indoor health here. I will suggest:
1. First -- make sure you install a CO Detector.
2. If you have natural or propane gas systems and wake up in the night or the morning with a headache or dizziness -- open a window first and ask questions later. Especially if more than one person in the house has symptoms. It sounds so logical now, but when you aren't sure what the affliction is, time is wasting.
All gas appliances are far from equal when it comes to safety, not just efficiency. We had a boiler that used inside house air and exhausted through a chimney, relying on heat stacking just like a fireplace does. Without explaining all the details I'll say that there are several ways this system can fail, and the consequences are huge if it is located in a room of your house. High efficiency units are available that bring outside air in for combustion, and expel clean air directly to the outdoors -- even a failure can't release CO into the house. With today's "tight house" construction techniques and materials there is great risk in relying on traditional indirect ventilation to ensure that a traditional gas appliance burns efficiently. Also, the indoor pollutants these "loose" systems can generate are bad for you even when they are not killing you on Christmas morning.
I wouldn't share this sort of thing on this blog if it was strictly a personal tragedy. It bears on design and construction in Davis. There is no code in our area, and no code enforcement that I know of. That means no inspection of systems by a qualified engineer. I have learned the hard way not to be AT ALL casual about systems involving energy. It is easy to get excited about good location, a good price, good design and energy cost savings, and sometimes a bit boring to consider the technical details of safety. Until you have a tragedy. And then it gets extremely "interesting." My commitment is that we will build extremely safe and well-engineered homes in Davis Riverwalk, per national building code and with well-reviewed systems and installation.
Have a great and safe New Year.