From my experience relative air humidity matters the most. I'm trying to keep it between 50-60%. When it gets too high I have difficulty breathing. When it goes

From my experience relative air humidity matters the most. I'm trying to keep it between 50-60%. When it gets too high I have difficulty breathing. When it goes too low my skin is flaking. Of the gas appliances... I have never heard anyone having issues with their gas stove as any cooking is usually followed by ventilating the kitchen. Although I've heard a lot of horror stories about CO (carbon monoxide) poisonings from faulty appliances like water heaters. A CO monitor is something I would recommend to anyone having gas appliances at home. Again, based on third-hand experience.