Efficiency Gap Caused by the Input Data in Evaluating Energy Efficiency of Low-Income Households’ Energy Retrofit Program

Energy efficiency policies are made to reduce the energy necessary to achieve a given level of indoor heating and to decrease the greenhouse gas emission worldwide. National and state regulators routinely tighten the energy efficiency building code appliance standards. In particular, for low-income households, the government has been implementing an energy efficiency program, and the most common measures include furnace replacement, attic and wall insulation, and infiltration reduction. The belief that the energy efficiency programs are beneficial and lead to energy reductions often fails, which is known as the ‘efficiency gap.’ This paper analyzed the effect of input data in calculating the energy savings of the energy efficiency program for low-income households as a cause of the energy efficiency gap in energy efficiency treatments for low-income households. According to the retrofit of the low-income household, the energy saving effect predicted through the input data of detailed measurement was 65%, which was higher than 41% of the conventional prediction method (walk-through audit). The resulting greenhouse gas (GHG) reduction effect was also the same as the energy savings, and the results predicted by the existing prediction methods were less predicted than the detailed measurement results.