We built our house 5years ago and installed the vermont castings WMC36 fireplace in the main living space. Our house is an open design - vaulted ceilings 3500sqft. We don't get much heat output from this one, and are wondering what our options are for replacing this for a more efficient wood burning unit. We would like to find an option that would be able to really heat the house and help to offset our heating bill. Chimney is SK8...any suggestions would be greatly appreciated.