There is a new set of standards coming for gas furnaces. The current minimum AFUE rating is 78%, though most are at 80%. The new requirements are possibly going to be between 95%-98%, which will mean a savings of billions of dollars — savings that could equal the gas and propane needs of New England for 17 years. The new condensation vented furnaces are cheaper to install in new construction because they do not require a metal and/or brick chimney. It is about $575 to $900 to replace an old furnace, but you would get your money back in about seven years with the savings from a more efficient unit.
Read the full article here: New Standards Proposed for Gas Furnaces