Refrigerator cost trap for low-income households: Developments in measurement and verification of appliance replacements

Energy efficiency of domestic refrigerators has markedly improved over recent years. Despite these improvements, low-income households in Australia still tend to own older and less energy-efficient refrigerators. Replacement of old refrigerators with energy-efficient appliances presents an important opportunity to reduce both greenhouse gas emissions and the electricity bills of households for sustainable development. This paper presents the measurement and verification of energy savings from a sample of 16 household refrigerator replacements under the Appliance Replacement Offer of the New South Wales Government, Australia. In-home monitoring and laboratory testing were conducted for both old and new refrigerators. A key challenge for this study was to estimate the energy savings of the replacement in each household based on limited in-home monitoring data. The annual energy savings from the refrigerator replacement in the households were estimated using the artificial neural networks (ANN) models for indoor air temperature prediction and the empirical models for the refrigerator energy consumption estimation. The experimental and estimation results both showed that most of the households achieved substantial energy savings from the replacement. The average annual energy cost savings and the average payback period of the refrigerator replacements were 53% and 4.3 years, respectively. It was also found that the energy savings could be compromised if the size of the new refrigerator was much larger than the old unit or if the efficiency of the old refrigerator was reasonably good.