We are seriously thinking about replacing our propane insert with a pellet insert. The current propane insert is vented through the chimney. What will we have to do for venting for the pellet insert. Is it going to be an expensive install? Also can anyone recommend an insert. we already have a pellet stove in the basement and love it, but we aren't getting enough heat on the main floor running it on 3, so this insert would be a supplement. Thanks for any info.