I have an old furnace that has been upgraded with a high efficiency oil burner. I am told that it is burning at 82% efficiency. Will a new furnace save me any money?
Yes it will. The 82% efficiency of your present furnace is combustion efficiency of your oil burner. Your older furnace was never tested and rated for AFUE (annual fuel use efficiency), and has a thick steel heat exchanger that has to be heated to transfer heat into the house. Your older furnace may only be capable of using 60-65% of the heat produced by the oil burner. A new furnace is built with thinner metal and multiple heat exchangers to transfer 80-85% of the heat into the house and is rated to have an AFUE of 80-85%.