There are such things as ventless gas heaters these days. They burn so clean that C O is not a major concern. The O2 sensor is sensitive enough that you are not even required to have a C O detector, although having one isn't a bad idea. The O2 sensor will kick off long before the C O detector senses an increase in C O.
I investigated these things very thoroughly two years ago. Several people in my neighborhood have ventless gas inserts in their fireplaces. They are not vented. They are in these tiny houses, 900 square feet. They are very safe. They are not meant to be used as a primary heat source, but definitely can be used as a supplemental heat source. A friend of mine has ten of them in his house. It's a very large house, over 6000 square feet, but he essentially has one in every room. People often forget that their gas oven is not vented but have no issues with cooking a turkey in it for multiple hours. -- Blue skies. Dan Rossi Carnegie Mellon University. E-Mail: [email protected] Tel: (412) 268-9081
