The Efficiency Ratings standards are set by the U.S. Department
of Energy under the National Appliance Energy Conservation Act
of 1987, which became effective January 1, 1992. All natural gas
heating systems have what's called an Annual Fuel Utilization
Efficiency (AFUE) rating. The rating is expressed in
percentages. |Minimum Efficiency Standards The higher the AFUE
rating – the more efficient the heating system – and the less
energy needed to heat your home. For example, a new, high-
efficiency furnace with a 94% efficiency rating provides 94
cents worth of heat from every energy dollar. By comparison, an
older, standard efficiency furnace with an efficiency rating of
60%, provides 60 cents worth of energy for every dollar spent.
Annual Savings: Simple Payback If you install a residential warm
air furnace at 90% AFUE vs. 80% AFUE, the estimated annual
savings in energy costs is $115 with a simple payback of
approximately 3 years*. *Analysis of annual savings provided by
the Consortium of Energy Efficiency, a