The need for reference machines when energy labelling electric household appliances that are tested to international standards.

There are over 80 countries in the world that currently use some kind of energy label for electric household appliances. In Europe, as an example, a lot of appliances are obliged to have an energy label when shown for sale, including online. Energy labels give relevant information to the consumers to help them make an environmentally beneficial choice when buying a new appliance. However, the desire for an energy efficient appliance does not outweigh the wish for good performance. Therefore, some energy labels provide information about the performance of the appliance based on international performance measurement standards (hereafter: "international standards"). Indeed, within the one appliance, increased performance can often mean increased energy consumption, so a balance between these parameters needs to be made by product designers and users. Unlike measurements that are traceable to Systeme Internationale units through metrological traceability chains, there is no natural reference data for performance measurements. Therefore, some international standards use a reference machine to relate their testing results to. The comparison of test and reference machine eliminates variances, for example, due to the auxiliary materials used and the influence of manual preparation or assessment methods. Three international standards that are currently using reference machines are examined closely in this paper. It is assessed how the reference machines and their testing results are treated, whether the reference machines are comparable with their corresponding test machines and if the use of a reference machine can be considered beneficial for the testing procedure. Additionally, three key questions are developed that will indicate whether 13 other international standards for electric household appliances could also benefit from using a reference machine. The paper concludes with six recommendations for standardisation groups and energy policymakers that will help with deciding whether a reference machine should be implemented. [ABSTRACT FROM AUTHOR]