A:Answer Absolute shortest? It can be raised 14-16 inches. So, can you? Yes. Should you? No. It would take a very skilled craftsman and the right equipment to cut the chimneys down and you'd likely void the warranty. Mine is the highest it will go without modification, 32½" from the ceiling. You can cut off 4½" of the inner stack and the brackets and not worry too much about the cleanliness/precision of your cuts. Any more and you have to cut the outer stack; removing the tabs which keep the bottom of the stack in precise position, and then you'd have to recreate the alignment slots for the clip that holds the bottom halves together, and then blah, blah, blah...
DON'T.
but yes, you can
