The main source of CO2 in a home are things that turn natural gas into heat, in particular gas stoves, and surprisingly common problems with gas water heaters a

The main source of CO2 in a home are things that turn natural gas into heat, in particular gas stoves, and surprisingly common problems with gas water heaters and gas furnaces. Saw a study that mentioned during inspections that only 25% of homes got rid of the CO2 exhaust to the degree they should. I personally ended up with crazy high CO2 levels, turns out hail crushed the exhaust lid, blocking the airflow, and led to scary high levels that were so bad hand writing changed. Took awhile to track it down, then I started graphing the CO2 levels, figured out was going on, and fixed it the same day. Fortunately hand writing returned to normal. Most homes aren't going to have serious CO2 levels from just human breathing. Sure modern homes can be so well insulated you have problems, but said homes should be engineered for a specific airflow exchange rate and use heat exchangers as necessary.