Impact of water hardness on energy consumption of geyser heating elements

Abstract

South Africa is an electricity-stressed country with a growing energy demand. Globally, hot water appliances are major consumers of electricity. Poor water quality for domestic purposes is a concern that may affect the efficiency of hot water appliances. Therefore, the Eskom Research, Testing, and Development Business Unit embarked on a study to examine total water hardness as a chemical parameter that may impact the power consumption of electrical geyser heating elements. An accelerated scaling method was developed to lime-scale the geyser heating elements for about 2 to 3 months. In addition, the geyser heating elements were tested with and without electronic descaler technology. The results showed that the accelerated scaling method developed for shortening the scaling time of geyser heating elements was successful. Furthermore, the results proved that scale formation of 1.5 kW and 3 kW geyser heating elements due to high total water hardness increased the power consumption by approximately 4% to 12%. This paper also presents energy-efficient electronic descaler technology as an alternative treatment of scaling for geyser heating elements.