Question: Fireplace Inserts I have asthma and have difficulty breathing when I turn up my gas furnace. I saw an article in last Saturday's Press Democrat about gas fireplace inserts having cleaner air. I am considering having one installed and was wondering if you could help me in any way. Answer: I'm not sure what type of gas furnace that you have, but most gas furnaces are vented, which means that they should put ALL products of combustion up the flue, not into the home. Perhaps there is something wrong with your system. Another thought is that even vented furnaces can move dust around and you may be reacting to this. Better filter systems, including duct-mounted and/or freestanding models, should help with this problem. You should call a heating professional about these problems. Most gas fireplace inserts are DIRECT VENTED, which means that they use no air from inside the home and place no exhaust there. As a result, you should not have a problem with these, although the circulation of existing household dust is still possible.