My stove has a 25ft ss liner to the top and I'm alittle concerned about possible overdraft during the winter usage.I tried the stove out 3 times a week or so ago when the outside temp was in the 30s and the fire seemed to be under control!I have read here that adding a damper on the pipe would be a good idea but my pipe is hidden behind the insert trim.What options do i have if i need more control on the downdraft?