NESS®, an Alternative System to Double Strand of Hot Water that Saves Water and Energy

Abstract

The work presented here aims to establish the main differences between two water saving systems: the double strand of hot water and an alternative solution that is able to recirculate all water normally wasted while waiting for hot water but employing conventional cold and hot water pipes installed at any building. This alternative system enables saving the same amount of water than the double strand of hot water, that is to say, all the cold water stored in the hot water pipe after a while without using hot water. This amount rises to approximately 27% of water usage in housing. The main difference with regard to the double strand of hot water is the energy consumption required to make each system work: while NESS® works under the user’s demand, the double strand of hot water is continuously or periodically working in order to keep the water over a certain temperature around 50 °C, whether there is hot water demand or not. NESS® is able to generate significant energy savings with regard to double strand of hot water, by employing 35% of the energy required by the second. In addition, NESS® presents various enhancing properties for both, professionals and those interested in sustainability such as its cost reduced to half the installation cost of double strand system or a third of the installation time.