The Therm-Liner heat exchangers are made from 1.4404 stainless steel. The surface is designed in such a way that the maximum possible energy extraction rate per m² of surface is achieved and dirt deposits are kept to a minimum. We always take the formation of a biofilm, which is inevitable to a certain extent, into account when designing the systems. In addition, the systems are designed for the minimal dry weather flow on a very conservative basis, so that the required output is available at any time. The heart of the heat exchangers is an integrated water cycle. The water in the module is colder than the wastewater in the sewer, so that the water in the module is warmed by the wastewater flowing over the module. This means that a heat transfer take place, although the wastewater and the water in the module are not in contact. The heat is transmitted via the stainless steel. The water, which is now heated, flows from the module through a pipe to the heating plant and forms the forward and return flow to the heat pump. Using a small amount of power, the heat pump makes the energy extracted from the sewer usable. A kWh of heat generated in this way consists of 75 % energy from wastewater, with only 25 % from electricity – this is energy efficiency and climate protection in action.
