Due to the sudden increase in LP prices I have finally decided to install my Caddy add-on wood furnace. I purchased this unit new on e-bay as a "scratch & dent" freight claim. It's never been installed/used. There is a small dent in the lower front right sheet metal, but doesn't appear to hurt the operation of the unit any. I live in a 1600 square foot story and half home with an unfinished basement. I currently use a high efficiency LP forced air furnace. There is an unlined brick chimney with two flues with nothing hooked to it. The interior measurement is 10" x 10" to the flue I can get to. What size/type of liner should I use 6" or 7"? Is it worth insulating? The chimney is approximately 20' from the hook-up to the top. Should I use wrapped insulation or pourable? Also, my chimney is located inside the walls of the house on the north side. It appears that the chimney was "cut-down" at one time. Is it possible to use chimney pipe to continue above the current brick chimney in order to provide the proper clearances? My house has slate type shingles, but I'm worried about getting the proper draft. I will be burning mostly oak and hickory well seasoned if it makes a difference. Any advice or suggestions will be greatly appreciated. Thanks.