Does anyone know how I can increase my burn time with this stove? I do not have a chimney damper. Currently I am burning red elm as that is the best wood that I have. Should I only cut oak from now on? (For next year) I can get flames for about two to three hours and coals for about 5 to 7 hours if I mix some oak and maple with the elm. Does this sound about right? My wife and I really like our stove. I just want to get more out of it. Our dealer is not much help. They did A great job with the install, but now they just want to deal with pellet stoves. Any heritage owners out there who can offer your knowledge? Thanks