Re: metal liner for chimney needed for new furnace?
Newer forced draft furnaces will not work properly emptying into an over sized chimney there is not enough heat or flow to get the proper draft. It must have a pipe 3" or 4" in diameter. High efficiency furnaces can be vented through PVC pipe and can be, and it is recommended, vented out a side wall. Both have restrictions on the number of elbows and length of pipe.
Be sure you live your life, because you are a long time dead.-Scottish Proverb