Question: Can you give me some advice on how what measures I can take to stop smoke from getting into my home when I open the furnace door to check, or add wood to the firebox. My steel chimney is at least 3 feet above the top of my roof, and there are no obstructions around the home. I clean the furnace and pipes monthly, and only burn seasoned wood, I am cutting next winters wood now. I have the furnace in the basement with a window open to allow fresh air for the fire. my home has a air to air heat exchanger, and I watch to ensure it is not on defrost when I open the furnace door. I was wondering if I can put a hood over top of the door that would capture the smoke, but vent it to where. I am looking for any suggestions. Thank in advance. Answer: You did not mention the total height of the chimney, which is very important for draft. Also, make certain the pipe connection from the furnace to chimney is as straight as possible. You may also be able to fabricate a smoke shield that would make the door opening smaller when open. This is often a sheet metal flap which hinges from the top of the inner door frame. An electric draft inducer can also be fitted to the smokepipe or chimney top.