Electrical water heaters continue to grow in popularity among consumers, but the conventional types waste energy. An EU initiative developed an energy-efficient alternative. Up until 2020, estimates show that about nine million water heaters will be installed yearly in new buildings. One million of those will be instantaneous electrical water heaters – models that combine a heating element through which hot water is produced on demand.
Traditional units that provide hot water take time to reach preferred temperatures, thus wasting water and energy.
The EU-funded RAPIDHEAT (The development of a high power density rapid response on demand water heating technology) project worked on a water heater for flexible and rapid response to hot water demand that will use new technologies for its heating element.
Work began by confirming the heating element's choice of materials and mechanical design. Project partners established that the costs of upgrading the electrical power supply to use such a heating element were not economical for many of the applications originally conceived for it.
An examination of the core technology's potential applications revealed several notable issues, namely operating voltage and costs associated with materials, infrastructure, peak demand and operations.
Based on the findings, the RAPIDHEAT team then proceeded with developing and testing a smaller element that is suitable for showers and vending machines.
The developed technology has proven effective thanks to its combination of high thermal conductivity with high electrical resistivity. This smaller, lighter heater responds faster, has lower thermal losses and outperforms existing competition.
Whereas current vending machines come with preheated water, the solution eliminates this need and provides freshly heated water at the appropriate temperature. What is more, instant hot water during showers provides water and energy savings for the home.
Thanks to RAPIDHEAT, it may not be long before optimised on-demand electric water heating technology becomes a part of commercial, industrial and public buildings as well as homes.