For Natural Gas Customers
An ENERGY STAR® certified natural gas furnace can save you 15% or more in natural gas/fuel costs, depending on the annual fuel utilization efficiency (AFUE) rating. The AFUE rating indicates how much of the natural gas is used for heat and how much is exhausted. The higher the AFUE rating number, the more energy efficient the furnace. A furnace with a 92% AFUE uses 92% of the natural gas for heat and 8% goes out the flue. A 96% AFUE furnace uses 96% of the natural gas for heat, with 4% going out the flue, which is a more energy efficient system.
For more information on energy efficient furnaces, visit the ENERGY STAR website