I would agree with the folks above. I wouldn't even use a gel-burning ventless fireplace first, because of the humidity issue and second, because I can't see any good coming out of introducing more chemicals into the living environment than there already are. Your typical house is loaded with chemicals (from carpet, paint, glue, etc.) and most houses do not have adequate air circulation (including mine). What you need is fresh air. You can purchase a direct-vent fireplace or space heater, meaning, it vents through the wall, where it stands (thus, without needed a long track of duct). You can order these products from a catalogue such as Jade Mountain www.jademountain.com (I'm a customer, not an affiliate). good luck to you; be healthy!