Treexza is a consultant in Home Improvement, especially anything concerning roofing. You might not realize this, but your roofing actually plays a great role in determining the energy bills you would have to pay for. At the point when your chimney is not being used, warm air from inside your house is actually spouting out the stack when the climate is cool. The damper in your firebox does little to stop it since it is not water/air proof. You should consider introducing a hermetically sealed stack top for this problem since it provides a good way for you to conserve energy.