How to Choose the Right Furnace

February 25, 2014

Furnace Ratings

A furnace fueled by natural gas, fuel oil, coal or electricity is the most common type of heating element in Virginia. Furnaces are rated according to the Annual Fuel Utilization Efficiency (AFUE) ratio.  AFUE is a measure of thermal efficiency—a dimensionless ratio of useful energy output to energy input, calculated as a percentage.  For example, a furnace with a 75% AFUE rating means 75% of the fuel used is directly supplied to generate heat.  The other 25% is wasted.  The AFUE ratio only takes into account a furnace’s fuel efficiency, including natural gas or heating oil, but not its electricity usage.  Higher AFUE ratings mean greater fuel efficiency.

In the early 90’s, The U.S. Department of Energy (DOE) and Federal Trade Commission required every make and model of furnace to have at least an AFUE of 78%.  In the next year or so, requirements for furnace ratings will increase again. This is important because of the general nationwide concern of fuel efficiency.

Based on research from the DOE, the primary consumption of all energy use in households is accredited to heating.  An alarming 40% of this energy is actually wasted.   This is why it’s critical to research AFUE ratings and heating energy consumption when installing a new system, or making the decision to repair an old one.  Some people aren’t aware that if their furnace is over a decade old it’s possible it does not meet current AFUE ratings. The age and size of a furnace heating system are major contributors to the energy efficiency. Older units aren’t as efficient, and systems that are too large for the space lead to wasteful usage.

The right size and rating of a furnace, as well as maintenance is important to ensure maximum efficiency.  The technicians at DSC can help with furnace inspection, repair or maintenance, to make sure your unit is correctly sized and meets ratings regulations.  With the right system, thermostat and insulation, heating your home can use less energy and save you money.  To learn more about furnace ratings and energy efficient heating equipment, call DSC today at (800) 832-0758.