If you use appliances that are powered by natural gas, it is important that the byproducts of the combustion are vented to the outside. If this doesn’t happen, it could lead to serious side effects, even to the point of death from CO poisoning. Sometimes, when the air pressure inside a home is very low, it could lead to backdrafting, where the exhaust is pulled into the home instead of being expelled.
It is possible that you might notice soot in the areas where the appliances are located, and this is an indicator that backdrafting is a problem. If you don’t see any soot, this doesn’t necessarily mean that you are safe however.
It is possible to test for backdraft using a smoke pencil, a puffer or a similar device and checking whether the smoke is being sucked into your home or not.
Having a carbon monoxide alarm could also help you spot a possible problem with backdrafts, and warn you when this lethal gas is present in your home.