Hi, actually two questions about a possible add on stove. 1. I would have to run about 40 feet of 18" x 18" duct from my add on wood stove before it connects to the central furnace main duct line. Then from there the heat would be distributed to each room from the central duct line. All in all, it would be about 60 to 80 feet of ducting before the heat reached each room. Is that too long? Too much heat loss? 2. I have a couple of room that are heated via coil ducts, there is also duct tape and foil tape a various junctures. Now I understand that you should only have metal duct for add on wood stoves. In this case the heat would travel over 40 feet before it ever reached any coil ducting. Is this a safe operation? Thanks, looking forward to spending time here.