Question: In The Q and A you suggest buying a "boot" round to rectangular, that is designed for heating duct. Can you use this thin metal to transition from a rectangular opening, in the top of my insert to a round opening, to connect to the pipe going up the chimney? Can I use regular heating duct pipe to vent my insert or do I need to buy the expensive stainless steel? I only use my stove a few times a month for about 12 hours at a time. Answer: Since it is back in the fireplace, it is probably not as much a safety issue as a longevity one. The best way to do it is to use the boots and stainless tubes designed just for this use. They are available from many stove dealers. Since heating duct is not made for this use, it might be difficult to find the components to suit your size needs. I can attest, however, that many of these "rigs" exist in the field.