Calculation of Energy Consumption

There are four categories of end-uses where energy consumption is estimated; heating & cooling, water heating, appliances (including misc plug loads), and lighting. The Home Energy Saver uses engineering models to estimate energy consumption for all these end-uses.

The legacy energy calculation methods used by the Home Energy Saver API are located here.

For both the “quick inputs” and “detailed inputs” levels, the models used to estimate energy consumption are identical, with user-entered values substituting for default values as the user progresses through the “detailed inputs” level.

The Home Energy Saver utilizes data from a variety of sources to provide default input values and energy consumption. The bulk of the data compilation for the Home Energy Saver was completed in 1997-1999, and the most current data available at that time was used. For time-sensitive series such as equipment efficiencies and state energy prices, the data are updated to the most current data available on an annual basis.