Lime-rich water has no problematic impact on the floor drain - neither on the gray water side (used shower water) nor the tap water side.
Lime precipitation in tap water applications in general
Problematic lime scale can generally form in water systems when the lime content reaches saturation of the water solution. This saturation depends mainly on the overall hardness and temperature of the water. Lime precipitates when water is heated because lime, as one of a few substances, has a so-called reverse solubility, which means that the solubility of lime decreases with increasing water temperature. Deposits in water engineering applications are therefore mainly formed either when water is heated above 60 °C (hard water), for example in water heaters, kettles, coffee makers, washing machines and so on; or when water evaporates and the mineral concentration passes the saturation level.
For Enduce energy recovery this means the following:
The gray water is cooled down in the heat exchanger, the solubility of lime in the water increases, and no lime-based deposits can form via precipitation as an effect of the temperature change. The heat recovery system also does not include wet dry zones (areas where water can evaporate and form lime deposits) that can lead to problematic deposits.
For the domestic water parts of the product, and in particular the cold water heated in the heat exchanger, the heating is very gentle in this context, up to a maximum of 35°C, compared to the water temperature of over 60°C that can cause problems in hard (calcareous) waters (Wennerholm, Resistance of water heaters, SP report 1995:22). The tap water side, for both cold and hot water, is permanently and completely wet, and therefore has no wet-dry zones. Overall, the risk of problematic limescale deposits is negligible even for the tap water.
This article was updated on 2024-10-09.
