The U.S. Department of Energy instituted an energy star system to rank the efficiency of major household appliances and energy consuming components of a home.  The primary objectives of this initiative was to reduce the energy burden of a typical household which results in major advantages for the government and consumer alike.  Two of these are:

• Reduces the energy requirement for a single household, thereby lowering consumption and making more energy available for use.

• Reduces the overall cost to the consumer for energy which places more disposable income for savings or other purchases.

How an energy rating works

Although individual components of a home may have an energy star rating this does not necessarily mean that a home is energy efficient.   Improper sized HVAC equipment, leaky duct work, a poorly sealed envelope, sloppy or insufficient insulation, poor quality window and door choices can all result in lowering the benefits of energy star rated products.  Based on this fact, the U.S. Department of Energy now looks at a home as an "energy efficient system" with all components working together to render the consumer an energy efficient, cost effective and more comfortable environment in which to live.

What an energy rater does

Using test equipment (a blower door and manometer) an energy rater takes measurements of the amount of air leakage into a home under various conditions.  Also, checking for duct work leaks (duct blaster test) and other various factors including insulation, windows and doors, house orientation and climate.  The test results are factored into a computer based program developed by the Department of Energy and Resnet.  The resulting calculation comes in the form of a HERS (Home Energy Ratings) number.  This HERS number determines the energy star rating which numbers from 1 to 5.  A five plus rating being the most energy efficient home.