I have a vc montpelier insert and i am not jumping for joy about its output. i have a 25 ft chimney which is on the exterior, they sealed the top tightly and i have a great draft, i can get the 600 sq ft to about 80, but down a tihgt hallway with a doorjam i struggle to hit 70. the thermostat is about 8ft down the hallway. 2 questions......will insulation in the chimney help and would you recommend a fan at the beginning of the hall? i believe i know the answer to both but am curious for input. and if the question comes up, no there is no blockplate, which after being here for about 4 months i dont know why an install would be done without a blockplate, and or insulation. i do realize that there is an ongoing battle to obtain as much heat as possible and i am quite enjoying the battle!