HUBER SE has developed the RoWin Heat Exchanger particularly for such problems. Its efficiency and reliability has already been proven impressively in several projects. Nevertheless, we still had to convince the Burgerbad spa operators in Leukerbad. The spa uses about 20% of the thermal spring water to offer its guest superb relaxation in its wide choice of pools. Although the thermal water loses some of its energy in the pools, it leaves the spa with a temperature of about 30 °C. The fact that this temperature level is sufficient to ensure the supply for a modern heating system shows the high energy potential of these thermal springs.
What distinguishes the Burgerbad project from previous projects is the fact that it is the first project for which the tank version of the HUBER RoWin Heat Exchanger has been used. The heat exchanger modules are not mounted in a stainless steel tank as usual but directly in the concrete tank. It is therefore possible to install the modules underground. In this case they are installed in a tank below the parking area on the rear side of the spa. In order not to lose some of the parking area, the tank has load-bearing covers. So, it is out of sight but thanks to its excellent performance certainly never out of mind.
As the water flows from the building by gravity there is no need for a pump to feed the heat exchangers, this saves energy and significantly improves efficiency.
The optimised interconnection of both heat exchangers ensures an output of 450 kW from a wastewater flow of 8 – 9 l/s. As about 300 kW are added from an external energy source the heat pump receives 750 kW with a temperature of about 20 °C and generates a heat output in excess of 1 MW which is available to be used for heating purposes within the Burgerbad spa. It is therefore not only the spa guests who profit from the heat from the thermal springs but also the Burgerbad operators.
A natural energy source, all-year-round availability, heat exchangers installed in the outflow from the spa, an excellent coefficient of performance of the heat pump – this list of benefits could certainly be continued. The Burgerbad operators realised how profitable it is to use heat recovered from wastewater. Once this news has spread beyond the Valais, Burgerbad will certainly not remain the only spa that optimises its energy balance with a HUBER RoWin Heat Exchanger.