I don't have a NC-30 but a EPA woodfurnace. Last year I installed it into a 7x11 chimney and used the furnace for the season. I had to constantly keep an eye on the unit and didn't seem to have the heat output it should have. This summer I installed a stainless rigid liner for our furnace. I can load the thing and 20 minutes later, close it down and watch it burn for hours. Heat output has increased greatly as well as burn times.
As it gets colder, so will the chimney. When you close down the stove, there will be less heat going into that chimney. Without a liner, those gasses will cool and draft will suffer. I agree 100%, get a liner in that chimney and that thing will wake up. I wanted to see a nc-30 in person at home depot, but they just had them in the box. If they are even close to the size of the box, damn those things are monsters.
As it gets colder, so will the chimney. When you close down the stove, there will be less heat going into that chimney. Without a liner, those gasses will cool and draft will suffer. I agree 100%, get a liner in that chimney and that thing will wake up. I wanted to see a nc-30 in person at home depot, but they just had them in the box. If they are even close to the size of the box, damn those things are monsters.