Impact of limestone incrustation on energy efficiency of washing machine

The reduction of energy consumption by household appliances is a global concern. In Europe, energy efficiency of clothe washing has increased significantly largely because of lower water wash temperatures, more efficient detergents, and the adoption of electronic control techniques. This paper addresses the problem of limestone formation on domestic appliances, in particular on the heating element of washing machines. An experimental study was conducted with the aim to assess the impact of an encrusted heating element in terms of energy consumption. The experiments were performed by following the instructions given by the regulation IEC 60456, which defines the main performance characteristics of electric household washing machines and describes the test methods for their measurement. Analysis of experimental data shows that limestone incrustation of the heating element causes a longer duration of the heating phase and a significant increase of energy consumption.