Given your description, I would say that an outside chimney in MI should be insulated, especially since it's a bit on the short side (Not problematically so, but 18' isn't going to draw as well as 25')
Most people find that distributing heated air with the furnace blower is a loosing game - especially if the furnace or any of the ducts run outside the heated envelope of the house - you get enough duct losses to cancel the heat from the insert.
I will let others comment on how well the Lopi Declaration will work in your situation.
Gooserider
Most people find that distributing heated air with the furnace blower is a loosing game - especially if the furnace or any of the ducts run outside the heated envelope of the house - you get enough duct losses to cancel the heat from the insert.
I will let others comment on how well the Lopi Declaration will work in your situation.
Gooserider
